Aromatic alkyl carboxylic acids and ester derivatives thereof for agricultural use to promote plant growth, yield, and protect plants against abiotic and biotic stresses

Abstract

Aromatic alkyl carboxylic acids and ester derivatives thereof useful for promoting plant growth, yield, and protect against abiotic and biotic stresses. The present invention relates to the use of aromatic alkyl carboxylic acids and ester derivatives thereof, or an agriculturally acceptable salt thereof, to increase growth and / or yield of a plant, at any developmental stage, as compared to the non-treated plant of the same species and at the same developmental stage. It also relates to the use of the compound to further increase in the adaptability of the plant to biotic and abiotic stresses.

Description

[0001] Aromatic alkyl carboxylic acids and ester derivatives thereof for agricultural use to promote plant growth, yield, and protect plants against abiotic and biotic stresses.

[0002] This application claims the benefit of European Patent Application EP24382797.9 filed on 23 July 2024.

[0003] Technical Field

[0004] The present invention relates to the field of plant biology, breeding and agriculture and refers to compounds which are useful for promoting growth of plants. It also relates to the ability of the compounds of the invention to increase plant resistance to stress.

[0005] Background Art

[0006] As the world’s population continues to grow, food security is becoming a major issue that is further complicated by the potential impact of climate change on crop productivity.

[0007] Extreme temperatures, drought, and soil salinization are the main adverse environmental conditions affecting crops (Gupta, 2020).

[0008] Abiotic stresses, in particular heat and drought, are increasing in frequency and intensity with climate change. In the past decade, all regions across the world had an average annual temperature change of at least 1.0 °C, with Europe leading with a 2.1 °C annual change. It is expected that global atmospheric temperature will rise by approximately 4 °C by 2080. Rising temperatures and drought may hamper food production, affecting both plants and animals alike.

[0009] For immobile plants, abiotic environmental factors are the leading detrimental factors affecting their growth and development. These abiotic stresses result in a range of responses in plants, which may alter biological processes such as gene expression and cell metabolism, among others. Moreover, high temperatures and drought often occur together. Under stress, plants tend to divert energy and resources away from growth and toward a stress response, to ensure survival. Due to this survival strategy, crops under these conditions are not only affected in terms of growth rate but also quality.

[0010] For these reasons, the study of signaling pathways which are activated by plants in response to stress is of great interest. According to Zhang Y., et al., in “Plants’ Response to Abiotic Stress: Mechanisms and Strategies”, Int J Mol Sc / . 2023 Jun 30; 24(13): 10915, in recent years, genome-wide association studies have identified regulators and natural allelic variants of crop responses to abiotic stresses. This has helped identify genes that may be used to produce more adaptive and higher yielding crops, introducing genetic variations, known as transgenic crops. Biotechnological production of plants tolerant to abiotic stress, in particular drought, have been produced previously (Martignago et al. 2020). Engineering hormone signaling produced plant with improved drought resistance due to reduced ethylene sensitivity and delayed senescence. The first ever transgenic with improved drought resistance to reach the market was Verdeca’s Drought Tolerance Soybeans HB4®(Bergau, 2019). Another example for improved adaptation to abiotic stress, in particular drought, has been associated with a receptor in WO2015177215A1 , where certain genes are modulated to generate a drought tolerant plant without penalizing overall plant growth (Fabregas, 2018).

[0011] WO2022253967A2 furthermore describes methods to genetically modulate plant adaptation traits to induce heat resistance, as well as increasing growth of the plant at different levels (hypocotyl, root, etc). Unfortunately, these solutions involving genetic modifications are both complex and costly.

[0012] Another strategy to improve plant growth under stress is chemical intervention. It is known that some compounds may be used to induce plant tolerance to abiotic stresses and help plants survive such periods, however, at the expense of growth rate and yield, since plant’s energy is focused on survival mechanisms.

[0013] For instance, exogenous application of different compounds, such a thiourea (TU), have already been described to stimulate defense mechanisms in plants under abiotic stress, according to Waqas M.A., et al., in “Potential Mechanisms of Abiotic Stress Tolerance in Crop Plants Induced by Thiourea”, Front. Plant Sci., 2019, vol. 10:1336. However, plant responses vary by plant species and depend on the concentration applied, since, for instance, high doses of TU can cause severe injury to wheat plants.

[0014] Finally, application of some carboxylic acids such as gamma-aminobutyric acid (GABA) and succinic acid to plants (roots, stems and / or foliage) to stimulate their growth has been described, for example, in US5604177. The use of salicylic acid to help increase plant tolerance to abiotic stress is also known, for example, from Roumani, A., et al., “Effects of salicylic acid and spermine foliar application on some morphological and physiological characteristics of isabgol (Plantago ovata Forsk) under water stress”, Agronomy Research 2019, vol. 17(4), p. 1735-1749.

[0015] Accordingly, from what is known in the art, there is still a need to find non-toxic compounds for different plant species to enhance their development and growth, in particular, when exposed to abiotic or biotic stress. This would help overcome the serious threat posed by abiotic and biotic stresses on the sustainability of food production systems.

[0016] Summary of Invention

[0017] Inventors have found that certain aromatic alkyl carboxylic acid compounds and ester derivatives thereof can be used to increase growth and / or yield of several plant species including relevant crops at different developmental stages along the plant life cycle in normal and multiple adverse environmental conditions. It has been shown, for instance, an increase in growth, biomass of mature plants and an accelerated seedling growth and germination rate. Furthermore, these compounds also provide a protective effect on several plant species against abiotic stresses, at different developmental stages, and additionally, may have a positive impact on growth rate, biomass, yield and may even enable fast recovery to severe drought periods, resulting in a higher recovery percentage of the tested plants. They may also provide a protective effect on several plant species against biotic stresses, at different developmental stages.

[0018] Therefore, these compounds are advantageous because they represent a new opportunity to increase growth rate and / or plant yields, and, in particular, to help them overcome drought, floods, cold and heat stress periods, particularly when applied as a preventive treatment before physiological symptoms of plant stress, which are ever-more frequent and prolonged due to climate change.

[0019] Accordingly, the present invention relates to the use of a compound of formula (I) or any stereoisomer or mixture thereof, or an agriculturally acceptable salt of any of them, to increase growth and / or yield of a plant, at any developmental stage, as compared to the non-treated plant of the same species and at the same developmental stage, wherein X is selected from C, O, and S; n is an integer from 0 to 3; when X is O or S, R3 and R4 are absent; when X is C, is a bond; R1 and R2 are radicals independently selected from H, halogen, OH, NH2, SH, (Ci-Ce)-alkyl, (Ci-Ce)-alkenyl, O-(Ci-Ce)-alkyl, and (Ci-C6)-alcohol, or alternatively, R1 and R2 form together a C=O double bond, being n =1 ; R3 is a radical selected from H, halogen, OH, NH2, SH, (Ci-C3)-alkyl, (Ci-C3)-alkenyl, O-(Ci-C3)-alkyl, (Ci-C3)-alcohol, and (Ci-C3)-carboxylic acid; R4 is a radical selected from

[0020] H, halogen, OH, NH2, SH, (Ci-C3)-alkyl, (Ci-C3)-alkenyl, O-(Ci-C3)-alkyl, and (C1-C3)- alcohol; Rs is a radical selected from H, halogen, OH, NH2, SH, (Ci-Cs)-alkyl, (Ci-Cs)- alcohol, (Ci-C3)-alkyl (C1-C3) carboxylate, O-(Ci-Cs)-alkyl, NH-(Ci-Cs)-alkyl, and S-(Ci- Cs)-alkyl; or alternatively,

[0021] R4 '• Rs together with the atoms to which they are attached form a feasible 5 to 7- membered ring, yielding to a compound of formula (h), wherein R1 and R2have the same meaning as in formula (I); A-D are independently selected from the group consisting of CH2, CH, NH, N, O, S, NCH3 and N-CO-CH3; m and o are integers independently selected from 0 to 1 ; the feasible 5 to 7-membered ring is selected from an aromatic carbocycle, an aromatic heterocycle, a non-aromatic carbocycle, and a non-aromatic heterocycle; the aromatic and the non-aromatic heterocycle rings have from 1 to 3 heteroatoms; R6-R9 in formula (I) and formula (h) are radicals independently selected from H, halogen, OH, NH2, NO2, SH, (Ci-Cs)-alkyl, (C1- Cs)-alcohol, (Ci-C3)-alkyl (C1-C3) carboxylate, O-(Ci-Cs)-alkyl, NH-(Ci-Cs)-alkyl, and S- (Ci-Cs)-alkyl, or alternatively, two adjacent R6-R9 together with the carbon atom to which are attached form a membered ring selected from an aromatic carbocycle, an aromatic heterocycle, a non-aromatic carbocycle, and a non-aromatic heterocycle; and Rwin formula (I) and (h) is a radical independently selected from H or (Ci-Cs)-alkyl.

[0022] Brief Description of Drawings

[0023] FIG. 1 shows phenotyping of the hypocotyl in 6-day-old seedlings wild type (WT) Arabidopsis seedlings exposed to compounds (la), (lb), (If) and (Id) of the invention (5 pM) at 22°C and 28 °C.

[0024] FIG. 2 shows thermomorphogenesis response (percentage hypocotyl growth change relative to non-treated) of Arabidopsis seedlings when exposed to compounds (la), (lb), (Id) and (If) of the invention (5 pM) at 22°C and 28°C.

[0025] FIG. 3 shows germination of cereal sorghum after four days in water (control) or supplemented with 0.5 pM of each compound (la), (lb), (Id) and (If).

[0026] FIG. 4 shows root length of four-day-old seedlings of cereal sorghum germinated in water (control) or supplemented with 0.5 pM of each compound (la), (lb), (Id) and (If).

[0027] FIG. 5a and 5b show seedling germination and root length of commercial tomato cv "Marmande” after 5 days germination in water (control) or supplemented with 0.5 pM of each compound [(la), (lb), (Id) and (If)].

[0028] FIG. 6 shows the distribution of 7-day-old shoots length of sorghum seedlings with no treatment (control) and treated with compounds (la) and (lb) (0.5 pM), in normal conditions and under osmotic stress conditions (liquid media containing sorbitol).

[0029] FIG. 7 shows phenotype of 7-day-old Arabidopsis seedlings with no treatment (WT) and treated with compounds (la), (lb), (Id) and (If) (5 pM), in normal conditions (untreated media) or stress (sorbitol) conditions.

[0030] FIG. 8 shows distribution of 7-day-old Arabidopsis seedlings root lengths (cm) in untreated media or sorbitol conditions.

[0031] FIG. 9 shows survival rate (%) of Arabidopsis mature plants under severe drought stress (12-day period), comparing non-treated plants (control) versus treated with foliar application with compounds (la) and (lb) (2 pM).

[0032] FIG. 10 shows distribution of photosynthesis parameters (Fv / Fm) during recovery period after severe drought stress period (12 days), comparing non-treated Arabidopsis mature plant (control) versus treated with foliar application with compounds (la) and (lb) (2 pM).

[0033] FIG. 11 shows photosynthesis parameters (Fv / Fm) before a severe drought period (12 days) and after drought (recovery period) comparing non-treated Arabidopsis mature plant (WT) versus treated by foliar application with 2 pM of compounds (la) and (lb).

[0034] FIG. 12 shows phenotype differences in Arabidopsis mature plants, comparing nontreated plants (WT) and plants treated by foliar application with 2 pM of compounds (la) and (lb), both before a severe drought period (12 days) and after drought (recovery period). FIG. 13 shows survival rate (%) of Arabidopsis mature plant under severe heat (42°C) stress period (5 days), comparing non-treated plant (control) versus treated with foliar application with compounds (la) and (lb) (2 pM).

[0035] FIG. 14 shows distribution of photosynthesis parameters (Fv / Fm) during recovery period after severe heat (42°C) stress period (5 days), comparing non-treated Arabidopsis mature plant (control) to treated by foliar application with compounds (la) and (lb) (2 pM).

[0036] FIG. 15 shows phenotype of commercial tomato “Marmande” non-treated plants (control) and treated by foliar application with (la), (lb), (Id) and (If) (2 pM) during recovery period after 15 days of severe drought.

[0037] FIG. 16 shows survival rate (%) of commercial tomato “Marmande” non-treated plants (control) and treated by foliar application with (la), (lb), (Id) and (If) (2 pM) after a severe period of drought (15 days).

[0038] FIG. 17 shows photosynthesis parameters (Fv / Fm) at day 0 and day 3 of severe drought period comparing commercial tomato “Marmande” non-treated plants (control) and treated by foliar application with (la), (lb), (Id) and (If) (2 pM).

[0039] FIG. 18 shows the distribution of photosynthesis parameters (Fv / Fm) for commercial tomato “Marmande” treated by foliar application with (la), (lb), (Id) and (If) (2 pM) at day 0 and day 3 of severe drought period.

[0040] FIG. 19 shows relative change (%) to control (non-treated plant) of stem length of commercial tomato “Marmande” treated by foliar application with (la), (lb), (Id) and (If) (2 pM) during the recovery period after 15 days of drought stress.

[0041] FIG. 20 shows relative change to control (non-treated plant) of biomass of commercial tomato “Marmande” treated by foliar application with (la), (lb), (Id) and (If) (2 pM) during the recovery period after 15 days of drought stress.

[0042] FIG. 21 shows representative images of the stomata cell guards by light microscopy after 2h treatment by foliar application with (la), (lb), (5 pM).

[0043] FIG. 22 shows stomata aperture ratio (width / length) after 2h treatment by foliar application with (la), (lb), (5 pM). FIG. 23 shows hydrotropic response (root curvature percentage) in Arabidopsis seedlings (7-day-old roots) after 24h of sorbitol-induced osmotic stress (270 mM) in WT without (control) and with compounds (la), (lb), (Id) and (If) in a concentration of 0.5 pM.

[0044] FIG. 24 shows phenotype of Arabidopsis mature plants untreated (control) and treated by foliar application with (la) and (lb) (2 pM) after 16h of cold stress at -6°C and 3 days at 22°C of recovering period.

[0045] FIG. 25 shows survival rate (%) of Arabidopsis mature plants untreated (control) and treated by foliar application with (la) and (lb) (2 pM) after a cold stress period at -6°C.

[0046] FIG. 26 shows photosynthesis parameters (Fv / Fm) of Arabidopsis mature plants untreated (control) and treated by foliar application with (la) and (lb) (2 pM) during the recovering period (3 days at 22°C) after 16h of cold stress at -6°C.

[0047] FIG. 27 shows phenotyping of the hypocotyl in 6-day-old seedlings wild type (WT) Arabidopsis seedlings exposed to compounds of the invention (li), (II), (Im), (In), (Ip), (Iq), (It, (ly), (Iz), (laa), (lab), (laf) at (5 pM) and (Ih), (Ij), (Ik), (lu), (Iv), (lx), (lac), (lad), and (lae) at (50 pM) at 28 °C.

[0048] FIG. 28 shows thermomorphogenesis response (percentage hypocotyl growth change relative to non-treated) of Arabidopsis seedlings at 28 °C when exposed to compounds of the invention (li), (II), (Im), (In), (Ip), (Iq), (It), (ly), (Iz), (laa), (lab), (laf) at (5 pM) at (50 pM) at 28 °C.

[0049] FIG. 29 shows thermomorphogenesis response (percentage hypocotyl growth change relative to non-treated) of Arabidopsis seedlings at 28 °C when exposed to compounds of the invention (Ih), (Ij), (Ik), (lu), (Iv), (lx), (lac), (lad), and (lae) at (50 pM) at 28 °C.

[0050] FIG. 30 shows germination of cereal sorghum after four days in water (control) or supplemented with 1 pM of each compound (Ip), (Iq), (II), (Ij), (ly), (lad), (Iz), (laa), (Iv) and (lac).

[0051] FIG. 31 shows root length (mm) of four-day-old seedlings of cereal sorghum germinated in water (control) or supplemented with compound (Ip), (Iq), and (II).

[0052] FIG. 32 shows root length (mm) of four-day-old seedlings of cereal sorghum germinated in water (control) or supplemented with compound (Ij), (ly), (lad), and (Iz). FIG. 33 shows root length (mm) of four-day-old seedlings of cereal sorghum germinated in water (control) or supplemented with compound (laa), (Iv) and (lac).

[0053] FIG. 34 shows survival rate (%) of commercial tomato “Marmande” non-treated plants (control) and treated by fertirrigation with (Iz), (laa), (Ip), (Iq), (II), (Iv), (lx), (lab), (lac), (Ij), (Ik), (ly), (lad), (It) and (lu). (1 pM) after a severe period of drought.

[0054] FIG. 35 shows phenotype of tomato “Marmande” treated by fertirrigation with (Iz), (laa), (Ip), (Iq), (II), (Iv), (lx), (lab), (lac), (Ij), (Ik), (ly), (lad), (It) and (lu) (1 pM) after a severe period of drought followed by two weeks of recovery (normal water)

[0055] FIG. 36 shows relative change to control (non-treated plant) of aerial (above ground) and root biomass of commercial tomato “Marmande” treated by fertirrigation with (Iz), (laa), (Ip), (Iq), (II), (Iv), (lx), (lab), (lac), (Ij), (Ik), (ly), (lad), (It) and (lu) (1 pM) after a severe period of drought.

[0056] FIG. 37 shows relative change (%) to control (non-treated plant) of plant height of commercial tomato “Marmande” treated by fertirrigation with (Iz), (laa), (Ip), (Iq), (II), (Iv), (lx), (lab), (lac), (Ij), (Ik), (ly), (lad), (It) and (lu). (1 pM) after a severe period of drought.

[0057] Detailed description of the invention

[0058] All terms as used herein in this application, unless otherwise stated, shall be understood in their ordinary meaning as known in the art. Other more specific definitions for certain terms as used in the present application are as set forth below and are intended to apply throughout the description and claims.

[0059] As used herein, the indefinite articles “a” and “an” are synonymous with “at least one” or “one or more.” Unless indicated otherwise, definite articles used herein, such as “the,” also include the plural of the noun.

[0060] The word “comprise” for the purposes of the present invention encompasses the case of “consisting essentially of” and “consisting of”.

[0061] In the context of the present invention, when referring to “compounds of formula (I)”, its stereoisomers and its salts are included.

[0062] The term “halogen” is meant to include the chemically related elements fluorine (F), chlorine (Cl), bromine (Br), and iodine (I).

[0063] The expression "effective amount" as used herein, refers to the amount of a compound that, when administered, is sufficient to increase growth and / or yield of a plant to some extent, and / or sufficient to protect a plant against stress, without hindering its developmental and / or growth process. The particular dose of the compound administered according to this invention will of course be determined by the particular circumstances surrounding the case, including the compound administered, its administration method, the particular species and / or developmental stage of the plant, the particular stress against which the compound protects the plant, and the similar considerations.

[0064] The expression “agriculturally acceptable excipients or carrier” refers to agriculturally acceptable materials, compositions, or vehicles. Each component must be agriculturally acceptable in the sense of being compatible with the other ingredients of the composition. It must also be suitable for use in contact with the plant without excessive toxicity or other problems or complications commensurate with a reasonable benefit / risk ratio.

[0065] Within the context of this specification, “a plant adaption trait” or “a plant trait” is defined as at least one of the following: the growth physiology, the tolerance to stress, a vascular transport and / or the defence response.

[0066] A “wild-type” or “normal” or “untreated” or “control” or “reference” plant in this specification is meant to comprise a plant that has not been genetically modified nor has been treated with a compound that may induce its tolerance to stress or affect its growth development. In the context of the present invention these terms are interchangeably and are regarded as synonyms. A control plant in this specification may also be a plant known to the person skilled in the art to be sensitive to stress, which can be abiotic stress, such as heat, osmotic, cold, freeze, floods and / or drought stress, or biotic stress, such as those produced by a living organism.

[0067] Within the context of this specification, an “abiotic stress” is defined as the negative impact of non-living factors, such as environmental stimulus, on a living organism, such as a plant. This negative impact is achieved due to a variation in the normal range of these non-living factors, such as a variation in temperature, that is sufficiently significant to affect the performance or physiology of the organism. Examples of abiotic stress may include floods, heat, cold, osmotic and drought stress, but also nutrient deficiency, high winds, floods, and other natural disasters.

[0068] Within the context of this specification, a “biotic stress” is defined as the negative impact caused by a living organism or pathogen, such as bacteria, viruses, fungi, parasites, and insects, on another living organism, such as a plant. The negative impact caused by biotic stress may also refer to a decrease in yield or growth of the plant due to competition with weeds. Examples of biotic stress may include those produced by a living organism selected from the group consisting of bacteria, viruses, fungi, parasites, and insects.

[0069] As mentioned above, the present invention relates to the use of a compound of formula (I) or any stereoisomer or mixture thereof, or an agriculturally acceptable salt of any of them, to increase growth and / or yield of a plant, at any developmental stage, as compared to the non-treated plant of the same species and at the same developmental stage.

[0070] In a particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compound of formula (I) is wherein X is C; n is an integer from 0 to 3; - is a bond; Ri and R2 are radicals independently selected from H, halogen, OH, NH2, SH, (Ci-Cs)-alkyl, (Ci-Cs)-alkenyl, O- (Ci-Ce)-alkyl, and (Ci-C6)-alcohol, or alternatively, R1 and R2 form together a C=O double bond, being n =1 ; R3 is a radical selected from H, halogen, OH, NH2, SH, (Ci-C3)-alkyl, (Ci-C3)-alkenyl, O-(Ci-C3)-alkyl, (Ci-C3)-alcohol, and (Ci-C3)-carboxylic acid; R4 is a radical selected from H, halogen, OH, NH2, SH, (Ci-C3)-alkyl, (Ci-C3)-alkenyl, O-(Ci-C3)- alkyl, and (Ci-C3)-alcohol; Rs is a radical selected from H, halogen, OH, NH2, SH, (Ci-Cs)- alkyl, (Ci-Cs)-alcohol, (Ci-C3)-alkyl (C1-C3) carboxylate, O-(Ci-Cs)-alkyl, NH-(Ci-Cs)-alkyl, and S-(Ci-Cs)-alkyl; or alternatively, R4'• Rs together with the atoms to which they are attached form a feasible 5 to 7- membered ring, yielding to a compound of formula (h), wherein R1 and R2 have the same meaning as in formula (I); A-D are independently selected from the group consisting of CH2, CH, NH, N, O, S, NCH3 and N-CO-CH3; m and o are integers independently selected from 0 to 1 ; the feasible 5 to 7-membered ring is selected from an aromatic carbocycle, an aromatic heterocycle, a non-aromatic carbocycle, and a non-aromatic heterocycle; the aromatic and the non-aromatic heterocycle rings have from 1 to 3 heteroatoms; R6-R9 in formula (I) and formula (h) are radicals independently selected from H, halogen, OH, NH2, NO2, SH, (Ci-Ce)-alkyl, (C1- C6)-alcohol, (Ci-C3)-alkyl (C1-C3) carboxylate, O-(Ci-Ce)-alkyl, NH-(Ci-Ce)-alkyl, and S- (Ci-Ce)-alkyl, or alternatively, two adjacent R6-R9 together with the carbon atom to which are attached form a membered ring selected from an aromatic carbocycle, an aromatic heterocycle, a non-aromatic carbocycle, and a non-aromatic heterocycle; and Rwin formula (I) and (h) is a radical independently selected from H or (Ci-Ce)-alkyl.

[0071] In a particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compound of formula (I) is wherein: X is selected from C, O, and S; n is an integer from 0 to 3; when X is O or S, R3 and R4 are absent; when X is C, - is a bond; R1 and R2 are radicals independently selected from H, halogen, OH, NH2, SH, (Ci-Ce)-alkyl, (Ci-Ce)-alkenyl, O-(Ci-Ce)-alkyl, and (Ci-C6)-alcohol; R3 is a radical selected from H, halogen, OH, NH2, SH, (Ci-C3)-alkyl, (Ci-C3)-alkenyl, O-(Ci-C3)-alkyl, (Ci-C3)-alcohol, and (Ci-C3)-carboxylic acid; R4 is a radical selected from H, halogen, OH, NH2, SH, (Ci-C3)-alkyl, (Ci-C3)-alkenyl, O-(Ci-C3)- alkyl, and (Ci-C3)-alcohol; Rs is a radical selected from H, halogen, OH, NH2, SH, (Ci-Cs)- alkyl, (Ci-Cs)-alcohol, (Ci-C3)-alkyl (C1-C3) carboxylate, O-(Ci-Cs)-alkyl, NH-(Ci-Cs)-alkyl, and S-(Ci-Cs)-alkyl; or alternatively,

[0072] R4 '• Rs together with the atoms to which they are attached form a feasible 5 to 7- membered ring, yielding to a compound of formula (h), wherein: R1 and R2 have the same meaning as in formula (I); A-D are independently selected from the group consisting of CH2, CH, NH, N, O, S, and NCH3; m and o are integers independently selected from 0 to 1 ; the feasible 5 to 7-membered ring is selected from an aromatic carbocycle, an aromatic heterocycle, a non-aromatic carbocycle, and a non-aromatic heterocycle; the aromatic and the non-aromatic heterocycle rings have from 1 to 3 heteroatoms; R6- 9 in formula (I) and formula (h) are radicals independently selected from H, halogen, OH, NH2, SH, (Ci-Cs)-alkyl, (Ci-Cs)-alcohol, (Ci-C3)-alkyl (C1- C3) carboxylate, O-(Ci-Cs)-alkyl, NH-(Ci-Cs)-alkyl, and S-(Ci-Cs)-alkyl.

[0073] The expression “agriculturally acceptable salt” refers to any salt formed, provided that it is a non-toxic salt for plants, in the present with an organic or inorganic cation or with an organic or inorganic anion. Suitable agriculturally useful salts are those formed with cations and anions that do not have any adverse effect on the action of the compounds according to the present invention.

[0074] Examples of suitable cations are alkali metals, such as lithium, sodium, and potassium, alkaline earth metals such as calcium, magnesium, and barium, and transition metals, such as manganese, copper, zinc, and iron. Other examples of suitable salts include methylamine, dimethylamine, triethylamine, triethanolamine, ethylenediamine, tris(hydroxymethyl)methylamine, and those formed with ammonium (NH4+) and substituted ammonium, such as ethylammonium, isopropylammonium, dimethylammonium, diisopropylammonium, trimethylammonium, tetramethylammonium, tetraethylammonium, tetrabutylammonium, 2-hydroxyethylammonium, 2-(2-hydroxyethoxy)ethylammonium, bis(2-hydroxyethyl)ammonium, benzyltrimethylammonium, and benzyltriethylammonium. Other suitable cations include phosphonium and sulfonium ions, such as tri(Ci-C4- alkyl)sulfonium, and sulfoxonium ions such as tri(Ci-C4- alkyl)sulfoxonium.

[0075] Examples of suitable anions include chloride, bromide, fluoride, hydrogen sulphate, sulphate, dihydrogen phosphate, hydrogen phosphate, phosphate, nitrate, citrate, hydrogen carbonate, carbonate, hexafluorosilicate, hexafluorophosphate, benzoate, besylate, maleate, Ci-Ce carboxylate, such as formate, acetate, propionate, and butyrate.

[0076] The compounds of formula (I) or their salts, or their stereoisomers, can exist in solvated, as well as unsolvated forms, including hydrated forms. Thus, they can contain in its structure stoichiometric amounts of solvent in the case of solvates, or of water in the case of hydrates. It is to be understood that the invention encompasses all such solvated, as well as unsolvated forms.

[0077] The present invention also relates to a method to increase growth and / or yield of a plant, at any developmental stage, as compared to the non-treated plant of the same species and at the same developmental stage, comprising administering an effective amount of a compound of formula (I) or an agriculturally acceptable salt thereof, as defined above.

[0078] All the particular embodiments of the use of the invention are also embodiments of the method to increase growth and / or yield of a plant, at any developmental stage, as compared to the non-treated plant of the same species and at the same developmental stage, comprising administering an effective amount of a compound of formula (I) or an agriculturally acceptable salt thereof, as defined above.

[0079] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where Re and Rg are radicals independently selected from H, OH, (Ci-Ce)-alkyl, and O- (Ci-C6)-alkyl.

[0080] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where Re and Rg are H.

[0081] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where Re-Rg in formula (I) and formula (h) are radicals independently selected from H, halogen, OH, NH2, SH, (Ci-Ce)-alkyl, (Ci-C6)-alcohol, (Ci-C3)-alkyl (C1-C3) carboxylate, O- (Ci-C6)-alkyl, NH-(Ci-C6)-alkyl, and S-(Ci-C6)-alkyl. In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where the biradical is attached to two adjacent Re-Rg positions, wherein the biradical and the two adjacent Re-Rg positions form a non-aromatic heterocycle or a non-aromatic carbocycle.

[0082] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where the biradical is attached to two adjacent Re-Rg positions, wherein the biradical and the two adjacent Re-Rg positions form a non-aromatic heterocycle.

[0083] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where the biradical attached to two adjacent Re-Rg positions is selected from the group consisting of -(C3-C4)-alkyl-, -O-(Ci-C2)-alkyl-O-, -NH-(Ci-C2)-alkyl-NH-, -S-(Ci-C2)-alkyl-S- , -O-(Ci-C2)-alkyl-NH-, -NH-(Ci-C2)-alkyl-O-, -O-(Ci-C2)-alkyl-NH-, -O-(Ci-C2)-alkyl-S-, -S- (Ci-C2)-alkyl-O-, -NH-(Ci-C2)-alkyl-S-, -S-(Ci-C2)-alkyl-NH.

[0084] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where Re, R? and Rs are radicals independently selected from H, OH, and -O-(Ci-Ce)-alkyl.

[0085] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where R?and Rs are radicals independently selected from H, OH, (Ci-Ce)-alkyl, and O-(Ci- Cej-alkyl.

[0086] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, R? and Rs are radicals independently selected from H, OH and -O-CH3.

[0087] In a more particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where X is C, n is 1 and Rs is COOH, and Re, R? and Rs are radicals independently selected from H, OH, and -O-(Ci-C6)-alkyl. In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where R3 is a radical selected from H, (Ci-C3)-alkyl, and (Ci-C3)-carboxylic acid.

[0088] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where n is an integer from 0 to 1 .

[0089] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, R1 and R2 are radicals independently selected from H, halogen, OH, NH2, SH, (Ci-Ce)-alkyl, (Ci-Ce)-alkenyl, O-(Ci-Ce)-alkyl, and (Ci-C6)-alcohol.

[0090] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, R1 and R2 form a C=O double bond. The expression “R1 and R2 form a C=O double bond” is intended to mean that R1 and R2 represent a carbonyl functional group in the Markush structure.

[0091] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where R1 and R2 are radicals independently selected from H and (Ci-Ce)-alkyl.

[0092] In a more particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where n is 0 to 1 , R1 and R2 are H.

[0093] In a particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where X is C.

[0094] In a particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where X is C, and n is 1.

[0095] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, R6-R9 in formula (I) and formula (h) are radicals independently selected from H, halogen, OH, NH2, SH, (Ci-Ce)-alkyl, (Ci-Ce)- alcohol, (Ci-C3)-alkyl (C1-C3) carboxylate, O-(Ci-Ce)-alkyl, NH-(Ci-Ce)-alkyl, and S-(Ci- Ce)-alkyl. In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where Ri-Rs and Rg are H. In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where RyRs are OH.

[0096] In a more particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where R3 is COOH.

[0097] In a more particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where X is C, n is 1 and Ra is COOH.

[0098] In a more particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where R1-R2, R4, and Re-Rg are H.

[0099] In a particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where Rs is selected from the group consisting of (Ci-Cs)-alkyl and O-(Ci-Cs)-alkyl. In a more particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where Rs is selected from the group consisting of methyl and methoxy.

[0100] In a particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where X is C and n is 0.

[0101] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where R3 or R4 is (Ci-Cs)-alkyl. In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where R3 or R4 is methyl.

[0102] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where R3 or R4, Rs-Re, and R9 are H. In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where RyRs are OH.

[0103] In a particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where X is O.

[0104] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where n is 3.

[0105] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where R1-R2, Rs-Rs, and Rs-Rg are H.

[0106] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where R5-R9 are H.

[0107] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where R? is O-(Ci-Cs)-alkyl. In a more particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (I) are those where Rs is methoxy.

[0108] In a particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (h) are those where the 5 to 7-membered ring is an aromatic ring. In a more particular embodiment, the aromatic ring is a carbocycle. In another particular embodiment, the aromatic ring is a heterocycle containing oxygen, sulphur and / or nitrogen. In a more particular embodiment of the use according to the invention, the heterocycle contains 1 to 3 heteroatoms. In a more particular embodiment of the use according to the invention, the heterocycle can be for instance pyridine, pyrimidine, pyrrole, pyrroline, pyrrolidine, pyrazine, pyridazine, imidazole, oxazole, isoxazole, thiazole, isothiazol, pyran, pyrazole, furane, thiophene, furazan.

[0109] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, R4 '• Rs together with the atoms to which they are attached form a feasible 5 to 7-membered ring, yielding to a compound of formula (h), and A-D are independently selected from the group consisting of CH2, CH, NH, N, O, S, and NCH3.

[0110] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, R4 '' '• Rs together with the atoms to which they are attached form a feasible 5 to 7-membered ring, yielding to a compound of formula (h), A is NH or N-CO-CH3, B is CH2, m is 1 , o is 0, and D is CH2. The radical N- CO-CH3 is intended to mean an N-substituted acetamide functional group. That is to say, in another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, A being N-CO-CH3 corresponds to a N- substituted acetamide group (the nitrogen atom has three chemical bonds).

[0111] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (h) are those where the 5 to 7-membered ring is a non-aromatic ring. In a more particular embodiment, the non-aromatic ring is a carbocycle. In another particular embodiment, the non-aromatic ring is a heterocycle containing oxygen, sulphur and / or nitrogen. In a more particular embodiment of the use according to the invention, the heterocycle contains 1 to 3 heteroatoms. In a more particular embodiment of the use according to the invention, the heterocycle can be, for instance, pyrrolidine, morpholine, piperidine, thianes, dithianes, tetrahydrothiophene, tetrahydrofuran, dioxolane.

[0112] In a more particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (h) are those where the non-aromatic heterocycle is a 6-membered ring. In a more particular embodiment, the compounds of formula (h) are those where m is 0, A is NH, C and D are CH2.

[0113] In a more particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (h) are those where n is 0.

[0114] In a more particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (h) are those where R6-R9 are H.

[0115] In another particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compounds of formula (h) are those where R3 is selected from H and (Ci-Ce)-alkyl. In a more particular embodiment, R3 is H. In another particular embodiment, R3 is methyl. In a particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, R in formula (I) and (h) is H.

[0116] In a particular embodiment of the use according to the invention, in combination with any of the embodiments above or below, the compound of formula (I) as defined above is selected from the following list:

[0117] 2-(2-methylphenyl)butanedioic acid (la), with CAS number 91143-76-9;

[0118] 2-(2-methoxyphenyl)butanedioic acid (lb), with CAS number 91144-07-9;

[0119] 2-(3,4-dihydroxyphenyl)propanoic acid (Ic), also known as 3,4-dihydroxy-a- methylphenylacetic acid, with CAS number 37697-50-0;

[0120] 1 ,2,3,4-tetrahydro-1-isoquinolinylacetic acid (Id), with CAS number 105400-81-5;

[0121] 2-(1 ,2,3,4-tetrahydroisoquinolin-1-yl)propanoic acid (le), with CAS number 2104602-06-2;

[0122] 3-(3,4-dihydroxyphenyl)propanoic acid (If), also known as di hydrocaffeic acid, with CAS number 1078-61-1 ;

[0123] 4-(4-methoxyphenoxy)butanoic acid (Ig), with CAS number 55579-99-2;

[0124] 3-(4-hydroxyphenyl)-2-oxopropanoic acid (Ih), with CAS number 156-39-8;

[0125] 3-(4-hydroxyphenyl)butanoic acid (li), with CAS number 6739-21-5;

[0126] 3-(4-methoxyphenyl)propionic acid (Ij), with CAS number 1929-29-9;

[0127] 3-(3-methoxyphenyl)propionic acid (Ik), with CAS number 10516-71-9;

[0128] 3-(2-hydroxyphenyl)propionic acid (II), with CAS number 495-78-3;

[0129] 3-(3-hydroxy-4-methoxyphenyl)propionic acid methyl ester (Im), with CAS number 129150-61-4;

[0130] 3-(3-hydroxy-4-methoxyphenyl)propionic acid (In), with CAS number 1135-15-5;

[0131] 3-(4-hydroxyphenyl)propionic acid (Io), with CAS number 501-97-3;

[0132] (3S)-3-Phenylbutyric acid (Ip), with CAS number 772-15-6;

[0133] (3R)-3-Phenylbutyric acid (Iq), with CAS number 772-14-5; phenylsuccinic acid (It), with CAS number 635-51-8;

[0134] 2,3-dimethyl-2-Phenylsuccinic acid (lu), with CAS number 3461-90-3;

[0135] (2-(4-methoxyphenyl)butanedioic acid) (Iv), with CAS number 6331-59-5;

[0136] 2-(2-chlorophenyl)butanedioic acid (lx), with CAS number 6954-40-1 ;

[0137] 2-(4-nitrophenyl)succinic acid (ly), with CAS number 21021-53-4;

[0138] 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolin-1-yl acetic acid (Iz), with CAS number 303094-23-7;

[0139] 6-methoxy-1,2,3,4-tetrahydroisoquinolin-1-yl acetic acid (laa), with CAS number 1028844- 20-3; methyl 2-(1 ,2,3,4-tetrahydroisoquinolin-1-yl)acetate (lab), with CAS number 91640-73-2; 2-(2-acetyl-1 ,2,3,4-tetrahydroisoquinolin-1-yl)acetic acid (lac), with CAS number 53921- 74-7; 1 ,2, 3, 4-tetrahydro-isoquinoline-1 -carboxylic acid (lad), with CAS number 151004-93-2; 3-(4-hydroxyphenyl)-2-hydroxypropanoic acid (lae), with CAS number 306-23-0; and 3-(1 ,3-benzodioxol-5-yl)-2-methylpropanoic acid (laf), with CAS number 77269-66-0. and having the following chemical structures:

[0140] The compounds to be used are either known or can be prepared analogously to the known compounds by the methods known in the art.

[0141] For instance, compounds (la), (lb), (It), (lu), (I v), (lx) and (ly) may be prepared following the method disclosed by Citterio, A., et. al., in “Reductive arylation of maleic and fumaric acid derivatives by arenediazonium and titanium (III) salts”, Synthesis, 1986, vol. 4, p. 308-9. Compounds (Id), (le), (Iz), (laa), (lab), (lac) and (lad) may be prepared following the method disclosed by Pelletier J. C., et al., in “Synthesis of the Marine Alkaloids Aaptamine and Demethyloxyaaptamine and of the Parent Structure Didemethoxyaaptamine”, J. Org. Chem., 1987, vol. 52, p. 616-622. Compound (If), (Ij), (Ik), (II), (Im), (In), (Io), (Ip), (Iq) and (lae) may be prepared following the method disclosed by Deng, L., et. al., in “Coordination Chemistry Based Approach to Lipophilic Inhibitors of 1-Deoxy-D-xylulose-5-phosphate Reductoisomerase”, J. Med. Chem., 2009, vol. 52, p. 6539-6542. Compound (Ig) may be prepared following the method disclosed by Hong, F.- T., in “Heteroatomic Effects on the Reducibility of C-2 Carbinol Centers in 6-Ethoxy-3,6- dihydropyrans and -thiopyrans”, J. Org. Chem, 1999, vol. 64, p. 3783-3786. Compound (le) may be prepared following the method disclosed by Limanskii et al. in “Synthesis of 2- (3,3-dimethyl-3,4-dihydroisoquino-1-yl) propanoic acid amides and their influence in blood coagulation” Pharm. Chem. J. 2009, vol. 43, 89-91.

[0142] Compounds (Ic) and (li) may be prepared by a process comprising two steps, first a hydroxyalkylation of an aromatic compound followed by a dihydroxylation or reduction of the formed alcohol. The first step may be conducted by reaction of pyrocatechol with 2- oxopropanoic acid in the presence of a base, such as sodium hydroxide, in aqueous media, and using a catalyst, such as alumina. The reaction takes place at a specific temperature in a range from 25°C to 50°C, generally for 6 to 9 hours. The reaction may be quenched with hydrochloric acid. In the second step, the resulting 2-(3,4-dihydroxyphenyl)- 2-hydroxypropanoic acid may be reacted with formic acid and a mixture of disulfurous acid and sodium salt (1 :2) in aqueous media, at a specific temperature in a range from 100°C to 130°C, generally, for 8 to 11 hours, obtaining compound (Ic) as a result.

[0143] Compound (Ih) can be prepared using as a starting material the hydroxyderivative described in US20160102042A1 and then performing a Jones oxidation using potassium dichromate in presence diluted sulfuric acid in a similar way as described by S. Naruto and A. Terada (Chem. Pharm. Bull., 1983, vol. 31 , p. 4286-4294) Optical Resolution and Determination of Absolute Configuration of (±)-2-[4-(2-Oxocyclopentylmethyl) phenyl] propionic Acids.

[0144] Compound (laf) can be prepared from piperonal, by reaction with methyl malonic acid with a mixture of pyridine and morpholine under reflux conditions as described by Achanta et al. (Drug Dev Res. 2019; 1-8. Synthesis and antimicrobial evaluation of piperic acid amides and their lower homologues) followed by a common catalytic hydrogenation with Pd / C like the one described by Garcia et al. (Tetrahedron, 1993, vol. 37, p. 8433-8440).

[0145] Some of the compounds of formula (I) and of formula (h) as defined above may have one or more chiral centres, meaning that R and S enantiomers, or racemates thereof, may be obtained.

[0146] Racemates and diastereomer mixtures obtained can be separated into the pure isomers or racemates in a known manner on the basis of the physicochemical differences of the components, for example by fractional crystallization. Racemates obtained may furthermore be resolved into the optical enantiomers by known methods, for example by recrystallization from an optically active solvent, chromatography on chiral adsorbents, with the aid of suitable microorganisms, by cleavage with specific immobilized enzymes, via the formation of inclusion compounds or by conversion into diastereomeric salts. Thus, for example a racemic compound of formula (I) can be separated into its enantiomers by reaction of the racemate with an optically active acid or bases and separation of the diastereomer mixture obtained. Examples of appropriate optically active acids are carboxylic acids such as tartaric or malic acid; sulfonic acids such as camphorsulfonic acid. Examples of appropriate optically active bases are naturally occurring alkaloids such as quinine or brucine, or basic amino acids such as lysine. The separation of the diastereomer mixture obtained in this manner, can be done on the basis of its differing solubilities. Then, the desired enantiomer can be liberated by the action of suitable agents. The most active enantiomer is advantageously isolated.

[0147] It is particularly surprising and advantageous that the compounds of the invention, as shown in the examples, are not only capable of accelerating growth and development rates of plants, in particular when applied to seeds and / or seedlings, which are cultivated under optimal conditions, but most importantly, they are capable of enabling plants to maintain growth and development rates and yield even when the plant is subject to abiotic conditions, such as floods, drought, heat, cold and / or osmotic stress. In comparison to a genetically modified plant, the present invention offers several advantages, not only from an economic perspective, but also for the simplicity of application of the compounds of the invention, at any developmental stage of the plant, and by well-known application methods.

[0148] Thus, in a particular embodiment of the use of the compounds of formula (I) as defined above, in combination with any of the embodiments above or below, the plant is a plant subject to an abiotic stress, and the use further comprises an increase in the adaptability of the plant to an abiotic stress. In a more particular embodiment of the use of the compounds of formula (I) as defined above, the abiotic stress is selected from the group consisting of floods, heat stress, drought stress, cold stress and osmotic stress.

[0149] In another embodiment of the use of the compounds of formula (I) as defined above, in combination with any of the embodiments above or below, the plant is a plant subject to a biotic stress, and the use further comprises an increase in the adaptability of the plant to a biotic stress. In a more particular embodiment of the use of the compounds of formula (I) as defined above, the biotic stress of the plant is that which is produced by a living organism selected from the group consisting of bacteria, viruses, fungi, parasites, and insects.

[0150] The expression “osmotic stress” response is meant to encompass a degree of adaptation to a sudden change in the solute concentration to which the plant it is exposed. Such osmotic stress might be provoked by an increased ion concentration (e.g. increased salinity, NaCI, heavy metals) or decreased water contents such as salt, which are mostly the results of drought or salinity / salt stress. Osmotic stress will result in a decreased water potential in the leaves of the plant and reduced turgor pressure in the cells. Osmotic stress includes changes in turgor, cell wall stiffness and integrity, membrane tension, and cell fluid volume at cellular level reducing plants growth and production.

[0151] The expression “drought tolerant” is meant to encompass a degree of adaptation to arid or drought conditions, reduced water availability or stress factors associated therein. Drought or water stress, for the purpose of this invention, is an extended period of time of 1 to 13 days, or 2 to 13 weeks, or longer, wherein a plant receives less water and is hence under drought stress.

[0152] In a particular embodiment of the use of the compounds of formula (I) as define above, in combination with any of the embodiments above or below, the plant receives less water than normal, for example 0.5% to 80% less water or less compared to normal or average conditions.

[0153] Drought is known to vary in length depending on the plant species and the conditions it typically grows in. Typically, a drought sensitive plant has a decreased survival rate of at least 5% to 90% or more during drought or after a drought period when compared to the survival rate of said plant when not exposed to drought. A drought resistant plant, a drought tolerant plant, a plant that survives longer during or after water or drought stress, and a plant with improved survival and / or growth during or after a drought or water stress period in the context of this application are considered synonymous to each other and used interchangeably.

[0154] Typically, an abiotic stress sensitive plant has a decreased survival rate, a reduced fertility and / or yield loss of at least 5% to 90% or more during or after a heat, osmotic, cold and / or drought stress period when compared to the survival rate, fertility and / or yield of said plant when not exposed to an abiotic stress.

[0155] Similarly, a biotic stress sensitive plant has a decreased survival rate, a reduced fertility and / or yield loss of at least 5% to 90% or more during or after a stress period produced by a living organism, when compared to the survival rate, fertility and / or yield of said plant when not exposed to a biotic stress.

[0156] In a particular embodiment of the use of the compounds of formula (I) as define above, in combination with any of the embodiments above or below, an abiotic stress sensitive plant treated with compounds of the invention may exhibit a growth adaptation to such stress. For instance, Example 4 shows enhanced growth in sorghum seedlings treated with compounds of the invention and subjected to osmotic stress, showing longer roots and shoots than control sorghum seedlings cultivated under the same conditions.

[0157] Likewise, mature plants treated with the compounds of the invention and subject to heat stress showed higher survival rate compared to the non-treated plants, as well as higher levels of photosynthesis rate, indicating a better performance during stress conditions. “Heat stress” and “elevated temperature” are synonymous in the context of the application. “Heat stress” or “elevated temperature”, for the purpose of this invention, is an extended period of time of at least 1 to 13 days, or 2 to 13 weeks, or longer, wherein the temperature is higher than the temperature under normal or average conditions, which may also be called the optimum growth temperature. This is the temperature at which a plant will grow the best. Such optimum temperature is different for each plant species / variety. The temperature is higher than the temperature under normal or average conditions when it is at least 1 to 15 degrees Celsius higher than the optimum growth temperature for each species or variety.

[0158] Obviously, “heat stress” is plant species specific and one plant species may experience a “heat stress” at a given temperature while another plant species will not experience such a “heat stress” at the same temperature. As soon as a plant (or plant species) has a decreased survival rate, reduced fertility and / or yield loss of at least 5% to 90% or more after a period of from 1-15 days during which said period the temperature is at least 1 to 15 degrees Celsius higher than the optimum growth temperature, one can say that this plant is sensitive for heat stress.

[0159] “Cold stress” and “low temperature” are synonymous in the context of the application. “Cold stress” or “low temperature”, for the purpose of this invention, is an extended period of at least 1 to 13 days, or 2 to 13 weeks, or longer, wherein the temperature is lower than the temperature under normal or average conditions, which may also be called the optimum growth temperature. This is the temperature at which a plant will grow the best. Such optimum temperature is different for each plant species / variety. Cold stress is characterized by three temperature ranges that are common for plant cultivation: (1) freezing (<0 °C), (2) chilling (>0 °C to growth limit), and (3) suboptimum (growth limit to optimum) conditions. Cold stress is characterized by three temperatures zones that are common for plant cultivation: (1) freezing (<0 °C), (2) chilling (>0 °C to growth limit), and (3) suboptimum (growth limit to optimum) conditions.

[0160] Obviously, “cold stress” is plant species specific and one plant species may experience a “cold stress” at a given temperature while another plant species will not experience such a “cold stress” at the same temperature. As soon as a plant (or plant species) has a decreased survival rate, reduced fertility and / or yield loss of at least 5% to 90% or more after a period of from 1-15 days during which said period the temperature is in any of the above-defined zones (1), (2) or (3), one can say that this plant is sensitive for cold stress.

[0161] The treated plants with the compounds of the present invention are resistant or tolerant to heat and cold stress, showing improved survival rate, fertility, growth and / or yield compared to the control plant as previously defined. The improvement is of at least 5% to 90% or more measured during the same period of time and under the same stress conditions.

[0162] Heat stress tolerance in this specification is meant to encompass a degree of adaptation to heat or elevated temperatures or stress factors associated with elevated temperatures. Examples of stress factors associated with heat or elevated temperatures include increased light intensity, increase of factors associated with greater water evaporation from soil such as decreased water availability or increase in soil solute (salt) concentrations. A plant that survives longer during or after heat stress and a plant with improved survival or growth during or after a heat period in the context of this specification are considered synonymous to each other and used interchangeably.

[0163] Cold-stress tolerance in this specification is meant to encompass a degree of adaptation to cold or low temperatures, freezing or stress factors associated with low temperatures. In chilling temperatures plants can be affected at any developmental stage, observed in the form of chlorosis, stiffness of seedlings, withering and often the death of seedlings. Effects can range from slight delays in development from growth inhibition to plant death. Other commonly observed stress responses include leaf chlorosis and necrotic lesions. Many physiological processes in plants are impeded by low temperatures, such as photosynthetic capacity, membrane rigidity, transpiration, and enzyme activity (Ritonga, et al., 2020). Together, these physiological effects of cold stress can result in poor agronomic performance. A plant that survives longer during or after cold stress and a plant with improved survival or growth during or after a cold period in the context of this specification are considered synonymous to each other and used interchangeably.

[0164] In a particular embodiment of the use of the compounds of the present invention, in combination with any of the embodiments above or below, the tolerance of the plant to an abiotic stress (preferably floods, heat, osmotic, cold and / or drought stress) has been improved, in that the plant may have an improved root hydrotropism, a greater hypocotyl growth, a greater petiole elongation, improved survival rate, an improved carbon utilization and / or reduced or repressed photorespiration pathway signalling in normal conditions and under heat stress, and / or a capacity to accumulate metabolites in normal conditions and under heat stress.

[0165] In a particular embodiment of the use of the compounds of the present invention, in combination with any of the embodiments above or below, the growth physiology of the treated plant, whether it is subjected or not to an abiotic or biotic stress, may be different to that of the control plant in that the treated plant may have an increased hypocotyl growth, an increased root growth, an increased petiole length, an altered flowering time and / or a modulation of a marker gene involved in phytohormone response, among other. Preferably, the hypocotyl growth of said plant is increased by at least 5% to 90% or higher when compared to the corresponding percentage of a control or reference plant under the same conditions. Preferably, the root growth of said plant is increased by at least 5% to 90% or higher when compared to the corresponding percentage of a control or reference plant under the same conditions.

[0166] Improved growth can be seen as increased accumulated biomass or increased average accumulated biomass. For example, the biomass of treated plants as envisioned by the invention compared to the biomass of wild-type plant is higher by 5% to 90% or more. Biomass can be determined be weighing the entire plant or a specified part thereof, such as roots, stem, stalk, leaves, fruit, seeds, or a combination thereof.

[0167] Within the context of this invention, a plant with improved root hydrotropism is defined as a plant with an increase in average or mean root curvature distribution, or an increase in percentage of roots with a curvature close to 180 degrees (Takahashi, 2002). Preferably, a plant with improved root hydrotropism contains a root curvature distribution where the percentage of roots with an angle between 160 and 180 degrees is increased by at least 5% to 90% or higher when compared to the corresponding percentage of a normal or wildtype plant under the same conditions (period of time and drought). Root curvature can be measured by growing seedlings vertically on MS standard medium or 14 MS standard medium and treated during 24-48 h or during 30 min to 24 hours in a gradient concentration of sorbitol, subsequently measuring 3 to 10-day old seedling root curvature and analysing the angle in Image J software. 14 MS standard medium is MS standard medium, which has been, diluted 14.

[0168] Within the context of the invention, the vascular transport properties of the treated plant according to the invention have been improved when plants treated with the compounds of the invention are compared to control plants, and the treated plant exhibits an increased accumulation of metabolites. Such metabolites may be osmoprotectant and / or relevant for the plant stress response and nutrient efficiency. Examples of such metabolites include sucrose, trehalose, ornithine, urea, proline, arginine, galacturonic acid, glycerol, erythritol, glutamine, maleic acid and beta alanine. Within the context of this invention, a plant exhibiting an increased accumulation of metabolites, wherein the length of the root is an indication of the status of the accumulation of metabolites, an increase of the length of the root usually correlating with an increased accumulation of metabolites. In a particular embodiment of the use of the compounds of formula (I) as define above, in combination with any of the embodiments above or below, the increase is an increase of at least 5% to 95% or more when compared to the length of the root in a control plant under the same conditions (time and heat and / or water availability).

[0169] Inventors have found, as can be seen in several Examples, that the application of the compounds of the invention, whether it be on plants subject to an abiotic or biotic stress or neither, promote development and growth rates at any stage of the plant’s life. The compounds of the invention have proven to be non-toxic at different dose ranges, for several species and families of plants tested and at different developmental stages, providing moreover benefits for such plants. Thus, in a particular embodiment of the use of the compounds of formula (I) as defined above, in combination with any of the embodiments above or below, the plant is a mature plant. In another particular embodiment of the use of the compounds of formula (I) as defined above, the plant is a seed or a seedling.

[0170] In an embodiment, in combination with any of the embodiments above or below, the compounds of formula (I) for use as defined above are in form of a solution or a suspension in water.

[0171] In a particular embodiment, in combination with any of the embodiments above or below, the compounds of formula (I) for use as defined above are in a concentration range from 0.001 nM to 1000 pM in the solution, suspension or emulsion to be administered to the plant. In a more particular embodiment, the compounds of formula (I) for use as defined above are in a concentration range from 0.001 pM to 500 pM in the solution or suspension to be administered to the plant. In a more particular embodiment, the compounds of formula (I) for use as defined above are in a concentration range from 0.01 pM to 200 pM in the solution or suspension to be administered to the plant. In a more particular embodiment, the compounds of formula (I) for use as defined above are in a concentration range from 0.5 pM to 50 pM in the solution, suspension or emulsion to be administered to the plant.

[0172] “Administering" or “applying” in the context of the invention comprises providing the compound (dissolved in water) to the plant by way of spraying or otherwise applying directly on or to the plant, to the seed, by any seed coating or directly to the soil or other support on which the plant is growing, or by dissolving it in the agar medium provided for plant germination. In an embodiment, in combination with any of the embodiments above or below, the compounds of the invention are applied to the plant, seed or soil through any administration form, such as injectable, and by any chemical delivery method, such as nanoparticles, conjugated with lipids, or hydrogels.

[0173] In an embodiment, in combination with any of the embodiments above or below, the compounds of the invention are applied to the plant, seed or soil by means of a spray. In a particular embodiment, the spray also comprises a surfactant.

[0174] For the purpose of the invention, an “adult” or “mature” plant, which are synonymous in the context of the application and may be used interchangeably, is defined as a plant of at least 2 weeks old. The person skilled in the art will be aware that the minimal age to reach adulthood may differ depending on the plant species. Depending on the developmental stage of the plant, the compounds of the invention may be applied using different methods, all of which show non-toxicity and effectivity in terms of conferring resistance and promoting growth to the plant. Thus, in a particular embodiment of the use of the compounds of formula (I) as defined above, in combination with any of the embodiments above or below, the plant is a mature plant, and the compounds of formula (I) are applied to the mature plant by foliar application.

[0175] Foliar application is known in the art, however, this method of application has not been described for the use of the compounds of the invention, let alone for the purpose of the present invention. Foliar application for the use of the present invention has proven to be a great method of supplying plant requirements for secondary nutrients and micronutrients, and in this case the compounds of the invention, since they are sprayed directly on the leaves and other developed parts of the plant, not only having an impact on the absorption of the compounds, but also simplifying the process. On the other hand, since seeds and / or seedlings have not yet developed, foliar application is not possible and other methods, which have proven to have effect in the Examples, are applied. Thus, in another particular embodiment of the use of the compounds of formula (I) as defined above, in combination with any of the embodiments above or below, the plant is a seed or a seedling, and the compounds of formula (I) are applied to the seed or seedling by immersion, coating, incubation and / or supplementation.

[0176] As mentioned above and as can be seen in the Examples, the compounds of the invention have proven to be non-toxic for several species and families of plants tested and at different developmental stages, providing benefits for such plants in terms of resistance to stress, development and growth rates, and crop yields. The compounds of the invention may be applied to different plant species, in the field of agriculture as well as other fields, including edible and non-edible species.

[0177] In an embodiment, plants to which the compounds of the invention may be applied include, but are not limited to, those belonging to the following groups: crops of cereals, oilseeds and protein crops, forest crops, viticulture, horticulture, sod, flax, cotton, vegetables, fruit gardens, aromatics and spice, arboriculture, and industrially cultivated plants for use in the production of raw materials. In another embodiment, plants to which the compounds of the invention may be applied are selected from the group comprising Rosaceae sp., Ribesioidae sp., Juglandaceae sp., Betulaceae sp., Anacardiaceae sp., Fagaceae sp., Moraceae sp., Pinaceae sp.,Oleaceae sp., Actinidaceae sp., Lauraceae sp., Musaceae sp., Rubiaceae sp., Theaceae sp., Sterculiceae sp., Rutaceae sp., Solanaceae sp., Vitaceae sp. Liliaceae sp., Asteraceae sp., Umbelliferae sp., Cruciferae sp., Chenopodiaceae sp., Cucurbitaceae sp., Papilionaceae sp., such as Graminae sp., Fabacae sp., as well as genetically modified homologues of these crops. In another embodiment, the compounds of the invention may be applied to a plant that is a food crop selected from the group comprising wheat, buckwheat, rice, brown rice, lentils, couscous, com, soybean, potato, barley, oat, quinoa, peas, red bean, and millet. In another embodiment, the plant is a vegetable crop selected from the group comprising tomato, radish, cress, cucumber, cabbage, watermelon, melon, cabbage, Chinese cabbage, scallion, onion, carrot, zucchini, and Arabidopsis thaliana. In another embodiment, the plant is a fruit crop selected from the group comprising avocado, apple, pear, date, peach, kiwi, grape, orange, persimmon, plum, apricot, banana, and tangerine. In another embodiment, the plant is a special crop selected from the group comprising mustard, ginseng, tobacco, cotton, sesame, sugar cane, sugar beet, peanut, and rapeseed. In another embodiment, the plant is a flower crop selected from the group comprising rose, gerbera, gladiolus, carnation, chrysanthemum, lily, and tulip. In another embodiment, the plant is a feed crop selected from the group comprising rye grass, red clover, orchard grass, alfalfa, and tall fescue.

[0178] The fact that the compounds show positive effects on different plant families is a great advantage in the field of agriculture, in particular in the fight for maintaining food security in an ever-more inhospitable world for plant cultivation, due to frequent periods of drought and extreme heat associated to climate change. The inventors have found that the compounds of the invention have effect on plant families which are crucial in terms of food and nutrition worldwide, in particular, cereals, such as wheat, solanaceous plants, from which we obtain tomatoes, potatoes, eggplants, among others, and crucifers, from which we obtain, for example, broccoli and cauliflower. Thus, in a particular embodiment of the use of the compounds of formula (I) as defined above, in combination with any of the embodiments above or below, the plant family is selected from Brassicaceae, Poaceae, and Solanaceae. In a more particular embodiment of the use of the compounds of formula (I) as defined above, the plant genus is selected from Arabidopsis, Solanum, Triticum, Sorghum.

[0179] Throughout the description and claims the term "comprise” and variations of the word, are not intended to exclude other technical features, additives, components, or steps. Furthermore, the word “comprise” encompasses the case of “consisting of”. Additional objects, advantages and features of the invention will become apparent to those skilled in the art upon examination of the description or may be learned by practice of the invention. The following examples and drawings are provided by way of illustration, and they are not intended to be limiting of the present invention. Reference signs related to drawings and placed in parentheses in a claim, are solely for attempting to increase the intelligibility of the claim and shall not be construed as limiting the scope of the claim. Furthermore, the present invention covers all possible combinations of particular and preferred embodiments described herein.

[0180] For reasons of completeness, various aspects of the invention are set out in the following numbered clauses:

[0181] Clause 1. Use of a compound of formula (I) or any stereoisomer or mixture thereof, or an agriculturally acceptable salt of any of them, to increase growth and / or yield of a plant, at any developmental stage, as compared to the non-treated plant of the same species and at the same developmental stage, wherein:

[0182] X is selected from O, S, and C; n is an integer from 0 to 3; when X is O or S, R3 and R4 are absent; when X is C, ■ is a bond;

[0183] Ri and R2 are radicals independently selected from H, halogen, OH, NH2, SH, (Ci-Ce)- alkyl, (Ci-Ce)-alkenyl, O-(Ci-Ce)-alkyl, and (Ci-C6)-alcohol;

[0184] R3 is a radical selected from H, halogen, OH, NH2, SH, (Ci-C3)-alkyl, (Ci-C3)-alkenyl, O- (Ci-C3)-alkyl, (Ci-C3)-alcohol, and (Ci-C3)-carboxylic acid;

[0185] R4 is a radical selected from H, halogen, OH, NH2, SH, (Ci-C3)-alkyl, (Ci-C3)-alkenyl, O- (Ci-C3)-alkyl, and (Ci-C3)-alcohol;

[0186] Rs is a radical selected from H, halogen, OH, NH2, SH, (Ci-C6)-alkyl, (Ci-C6)-alcohol, (Ci- C3)-alkyl (C1-C3) carboxylate, O-(Ci-C6)-alkyl, NH-(Ci-C6)-alkyl, and S-(Ci-C6)-alkyl; or alternatively,

[0187] R4 '' '• Rs together with the atoms to which they are attached form a feasible 5 to 7- membered ring, yielding to a compound of formula (h), wherein:

[0188] R1 and R2 have the same meaning as in formula (I);

[0189] A-D are independently selected from the group consisting of CH2, CH, NH, N, O, S, and NCH3; m and o are integers independently selected from 0 to 1 ; the feasible 5 to 7-membered ring is selected from an aromatic carbocycle, an aromatic heterocycle, a non-aromatic carbocycle, and a non-aromatic heterocycle; the aromatic and the non-aromatic heterocycle rings have from 1 to 3 heteroatoms;

[0190] Re-Rg in formula (I) and formula (h) are radicals independently selected from H, halogen, OH, NH2, SH, (Ci-Ce)-alkyl, (Ci-C6)-alcohol, (Ci-C3)-alkyl (C1-C3) carboxylate, O-(Ci-Ce)- alkyl, NH-(Ci-C6)-alkyl, and S-(Ci-C6)-alkyl.

[0191] Clause 2. Use according to clause 1 , wherein Re and Rg are H.

[0192] Clause 3. Use according to any of the clauses 1-2, wherein R? and Rs are radicals independently selected from H, OH, (Ci-Ce)-alkyl, and O-(Ci-Ce)-alkyl.

[0193] Clause 4. Use according to any of the clauses 1-3, wherein R3 is a radical selected from

[0194] H, (Ci-C3)-alkyl, and (Ci-C3)-carboxylic acid.

[0195] Clause 5. Use according to any of the clauses 1-4, wherein X is C, n is 1 and Rs is COOH.

[0196] Clause 6. Use according to any of the clauses 1-5, wherein the compound of formula (I) is selected from the following list:

[0197] 2-(2-methylphenyl)butanedioic acid (la);

[0198] 2-(2-methoxyphenyl)butanedioic acid (lb);

[0199] 2-(3,4-dihydroxyphenyl)propanoic acid (Ic);

[0200] I ,2,3,4-tetrahydro-1-isoquinolinylacetic acid (Id);

[0201] 2-(1 ,2,3,4-tetrahydroisoquinolin-1-yl)propanoic acid (le);

[0202] 3-(3,4-dihydroxyphenyl)propanoic acid (If), and

[0203] 4-(4-methoxyphenoxy)butanoic acid (Ig).

[0204] Clause 7. Use according to any of the clauses 1-6, wherein the plant is a plant subject to an abiotic stress, and the use further comprises an increase in the adaptability of the plant to an abiotic stress.

[0205] Clause 8. Use according to clause 7, wherein the abiotic stress is selected from the group consisting of heat stress, drought stress, cold stress and osmotic stress.

[0206] Clause 9. Use according to any of the clauses 1-6, wherein the plant is a plant subject to a biotic stress, and the use further comprises an increase in the adaptability of the plant to a biotic stress. Clause 10. Use according to any of the clauses 1-9, wherein the plant is a mature plant.

[0207] Clause 11. Use according to clauses 10, wherein the compound of formula (I) is applied to the mature plant by foliar application.

[0208] Clause 12. Use according to any of the clauses 1-9, wherein the plant is a seed or a seedling.

[0209] Clause 13. Use according to clauses 12, wherein the compound of formula (I) is applied to the seed or seedling by immersion, coating, incubation and / or supplementation.

[0210] Clause 14. Use according to any of the clauses 1-13, wherein the plant family is selected from Brassicaceae, Poaceae, and Solanaceae.

[0211] Clause 15. Use according to clause 14, wherein the plant genus is selected from Arabidopsis, Solanum, Triticum, Sorghum.

[0212] Clause 16. Use according to any of the clauses 1-3, wherein the feasible 5 to 7- membered ring is selected from a non-aromatic carbocycle and a non-aromatic heterocycle.

[0213] Abbreviations

[0214] Wild type (WT), materials and methods (MM), interquartile range (IQR).

[0215] Materials and methods

[0216] MM.1. Sterilized Arabidopsis seeds (Col-0) were vernalized at 4°C for 48h and germinated in 0.5 MS soft agar media + 5 pM compounds (la), (lb), (Id) and (If) at 22 °C or 28°C.

[0217] Hypocotyl length was measured after 6 days at 28°C or 22°C light intensity around 120 pmoles / m2 / s and 60% relative humidity. For compounds (li), (II), (Im), (In), (Ip), (Iq), (It), (ly), (Iz), (laa), (lab), (laf), (Ih), (Ij), (Ik), (lu), (Iv), (lx), (lac), (lad) and (lae), sterilized Arabidopsis seeds (Col-0) were vernalized at 4°C for 48h and germinated in 0.5 MS liquid media + 5 pM or 50 pM compounds at 22°C. Hypocotyl length was measured after 3 days exposure at 28°C light intensity around 120 pmoles / m2 / s and 60% relative humidity.

[0218] MM.2. Sterilized Sorghum (Sorghum bicolor) TX430 seeds were soaked in plates with a primming solution of (0.5 pM) for each compound ((la), (lb), (Id) and (If)) or water (control) at 28°C for germination. After 4 days the number of germinated seeds and the length of the root and aerial part was measured. The experiment was performed with 12 seeds per treatment and 3 independent replicas. For compounds (Ip), (Iq), (II), (Ij), (ly), (lad), (Iz), (laa), (Iv) and (lac) or water (control), sterilized Sorghum (Sorghum bicolor) TX430 seeds were soaked in plates with a primming solution of (1 pM) for each compound (Ip), (Iq), (II), (Ij), (ly), (lad), (Iz), (laa), (Iv) and (lac) or water (control) at 28°C for germination. After 4 days the number of germinated seeds and the length of the root and aerial part was measured. The experiment was performed with 12 seeds per treatment and 3 independent replicas.

[0219] MM.3. Sterilized tomato commercial variety "Marmande" were soaked in plates with a primming solution of (0.5 pM) for each compound [(la), (lb), (Id) and (If)) or water (control)] at 24°C for germination. After 3 days the number of germinated seeds and the length of the root and aerial part were measured. The experiment was performed with 20 seeds per treatment and 3 independent replicas.

[0220] MM.4. Sterilized and germinated Sorghum (Sorghum bicolor) TX430 were primed with a 0.5 pM solution for each compound [(la) and (lb)) or with water (control)]. Three day-old- seedlings transferred either to control or to 270 mM sorbitol for 72h. Aerial part length was measured after 72h of treatment.

[0221] MM. 5. Sterilized Arabidopsis seeds were vernalized at 4°C for 48h and germinated in 0.5 MS agar at 22°C. Seedlings of 3-day-old were transferred to either control or 270 mM sorbitol media with the addition of each compound (la), (lb), (Id), and (If) independently at 5 pM, or without treatment. Root length was measured after 4 days of treatment.

[0222] MM.6. Sterilized Arabidopsis seeds were germinated in MS1 / 2 agar plates and transferred after 1 week to pots containing 30 ± 1 g (8:1 :1 turba, vermiculite and perlite). Three-week- old plants were treated by foliar application with a solution of each compound [(la) and (lb) or with water (control)] and subjected to severe drought stress by withholding water for 12 days followed by re-watering for one week.

[0223] Formulation containing the compound and Tween 20 at 0.01% emulsifier were sprayed on leaves till run off. A solution of Tween 20 at 0.01% was used as control.

[0224] After the 7-day recovery period, biomass, survival rate and photosynthesis parameters were measured. The experiment was performed with 15 plants and 3 independent replicas.

[0225] MM.7. Sterilized Arabidopsis seeds were germinated in MS1 / 2 agar plates and transferred after 1 week to pots containing 30 ± 1 g (8:1:1 turba, vermiculite and perlite). Three-week- old plants were treated by foliar application with a 2 pM solution of each compound [(la) and (lb) or with water (control)] and subjected to 3 days at 42 °C. Formulation containing the compound and Tween 20 at 0.01% emulsifier were sprayed on leaves till run off. A solution of Tween 20 at 0.01% was used as control.

[0226] After the 7-day recovery period, biomass, survival rate and photosynthesis parameters were measured. The experiment was performed with 12 plants and 3 independent replicas.

[0227] MM.8. Sterilized tomato commercial variety "Marmande" were germinated at 24°C for germination and transferred to pots containing (3:1 :1 turba, vermiculite, perlite). Two-week old plants were treated by foliar application with a 2pM solution of each compound [(la), (lb), (Id) and (If)) or with water (control)]. Formulation containing the compound and Tween 20 at 0.01 % emulsifier were sprayed on leaves till run off. A solution of Tween 20 at 0.01% was used as control. After two daily applications, plants were subjected to severe drought stress by withholding water for 15 days followed by re-watering for the following 2 weeks. After 15 days of recovery: biomass, survival rate and photosynthesis parameters were measured. The experiment was performed with 10 plants and 3 independent replicas. For compounds (Iz), (laa), (Ip), (Iq), (II), (Iv), (lx), (lab), (lac), (Ij), (Ik), (ly), (lad), (It) and (lu) sterilized tomato commercial variety "Marmande" were germinated at 24°C for germination and transferred to pots containing (3:1 :1 turba, vermiculite, perlite). Two-week old plants were treated by fertirrigation with a 1 pM solution of each compound (Iz), (laa), (Ip), (Iq), (II), (Iv), (lx), (lab), (lac), (Ij), (Ik), (ly), (lad), (It) and (lu). After the priming treatment, plants were subjected to severe drought stress by withholding water for 11-13 days followed by re-watering for the following 2 weeks. After 11-13 days of recovery: biomass, survival rate and photosynthesis parameters were measured. The experiment was performed with 8 plants and 3 independent replicas.

[0228] MM.9. Epidermal peels of expanded mature leaves from tomato cultivated (cv) “Marmande”, from abaxial sides of leaves in continuous light, were incubated in a stomatai opening solution for 2h. In some cases treatment with compounds (la), (lb), at 5 pM was added to the solution, and in others, the plants were left untreated (control). Imaging of epidermal strips performed using Axiophot microscope. Stomatai aperture was scored as width / length pore ratio using Image J software. Data were retrieved from n=60 stomata.

[0229] MM. 10. Sterilized Arabidopsis seeds were germinated in MS1 / 2 agar plates and transferred after 1 week to pots containing 30 ± 1 g (8:1 :1 turba, vermiculite and perlite). Three-week-old plants were treated by foliar application with a solution of each compound (la) and (lb) (2 pM) or with water (control) and subjected to cold stress by incubation at -6 °C for a period of 16h. The formulation containing the compound of the invention and Tween 20 at 0.01 % emulsifier were sprayed on leaves till run off. A solution of Tween 20 at 0.01% was used as control. Examples

[0230] Example 1 : Treatment with compounds (la), (lb), (Id) and (If) seedlings promote plant growth under heat stress in Arabidopsis.

[0231] Plants were cultivated for a period of six days on agar media, with the media supplemented with 5 pM of compounds (la), (lb), (Id) and (If). Two different temperature conditions were tested: 22 °C as a control (optimal) and 28 °C to simulate elevated suboptimal temperatures (Rivero, et al., 2014). The results showed that these compounds have a protective effect against the adverse effects of high-temperature exposure without compromising overall growth. In a WT background, treatment with compounds promote growth rate of the hypocotyl compared to growing in media without addition of compounds. At 22°C, there is an increase of the hypocotyl length of +25%, +15.9%, +13.9%, and +6.41% from compound (la), (lb), (If) and (Id), respectively. At 28°C, the same increase is about 40.5%, 15.4%, 31.6%, and 56.8% from compound (la), (lb), (If) and (Id), respectively (FIG. 1 and FIG. 2). This experiment was performed in triplicate, following the methods described in MM1 Data for FIG.2 were retrieved from three independent biological replicates (n>80 per replicate).

[0232] Example 2: Sorghum cereal treated by seed immersion with compounds of the invention showed enhanced seedling development and growth.

[0233] The impact of compounds (la), (lb), (Id) and (If) on germination rate and seedling growth was assessed in sorghum seeds as cereal model following the methods described in MM.2. Four-day-old seedlings of sorghum were germinated in water (control) or supplemented with 0.5 pM of each compound [(la), (lb), (Id) and (If)]. Sorghum seeds exposed to compounds of the invention exhibited notable acceleration in seedling development during a period of 4 days leading to an increase in overall seedlings growth (FIG. 3). The phenotype of root length revealed a significant effect on promoting root growth. Compound (If) exhibited a remarkable performance by promoting root length up to 3X compared to non-treated followed by compound (Id) with a similar growth rate in root development (FIG. 4). Boxplots depict the distribution of 4-days-old root length of control (untreated) and 0.5 pM compounds (la), (lb), (Id) and (If) treatment. Boxplots represent the median and interguartile range (IQR). Different letters represent significant differences (p-value < 0.05). Data were retrieved from three independent biological replicates (n > 60). The incubation of seeds with the compounds of the invention did not show any indications of toxicity on seedling development. In addition, these compounds demonstrated a beneficial effect by significantly promoting seedling development and fostering a notable root growth rate in sorghum. In summary, this study underscores the non-toxic and high beneficial impact of these compounds on seedling development in sorghum.

[0234] Example 3: Seed coating with compounds (la), (lb), (Id) and (If) showed enhanced germination rate and seedling growth in tomato (Solanum LycopersicumY

[0235] The effect of the compounds (la), (lb), (Id) and (If) on germination rate and seedling development was also assayed for tomato as an important agronomic crop model. The experimental assays were performed with four replicas following the methods described in MM.3. The results revealed that tomato seeds, when germinated in water supplemented with 0.5 pM of compounds (la), (lb), (Id) and (If) over a 5-day period, exhibited enhanced seed germination rates, accelerated seedling growth, and increased root development compared to the control group (water). Under non-stress conditions, root length measurements demonstrated a significant increase (indicated by asterisks on the graph) in root development during the germination phase, with all tested compounds performing similarly, i.e. added value compared to the control (FIG. 5a and FIG. 5b). Data were retrieved from four independent biological replicates (n > 50). Boxplots depict the distribution of 5-days-old root length of control (untreated) and 0.5 pM compounds (la), (lb), (Id) and (If) treatment. Boxplots represent the median and interguartile range (IQR). Different letters represent significant differences (p-value < 0.05). Collectively, these findings suggest that the germination of tomato seeds with treatments of compounds (la), (lb), (Id) and (If) had no adverse effects on this plant species and instead promoted overall seedling growth.

[0236] Example 4: Seed coating with compounds (la) and (lb) provides protection against osmotic stress in sorghum seedlings.

[0237] To determine the role of compounds (la) and (lb) in the response to drought stress, an analysis of overall seedling growth rate and primary root growth was conducted in sorghum seedlings following the methods described in MM.4. Sorghum seedlings that were germinated in the presence of 0.5 pM of compound (la), (lb) or not treated (control) were subjected to osmotic stress by transferring them to liguid media containing sorbitol. Subseguently, the level of inhibition in both shoots and roots growth in sorbitol relative to control conditions (in water, under no osmotic stress) was guantified. Results showed that sorghum seeds when germinated in the presence of 0.5 pM of compounds (la) and (lb) exhibited enhanced overall growth under stress conditions. These seedlings displayed longer roots and shoots compared to the control (with no treatment) (FIG. 6). A significantly lower level of inhibition in shoots growth under osmotic stress was observed in pre-treated seedlings with compounds in contrast to the non-treated seedlings. In addition to the protection effect against osmotic stress, in control conditions, both compounds promote shoots and roots growth by increasing 50% shoots growth for compound (la) and achieving a 25% increase for compound (lb). Boxplots in FIG. 6 depict the distribution of 7-day-old shoots lengths in water or sorbitol, both for seedlings treated with compounds (la) and (lb) or non-treated seedlings (control). Data was retrieved from 3 independent biological replicates (n > 60). Boxplots represent the median and interquartile range (IQR). Different letters represent significant differences (p-value < 0.05).

[0238] Example 5: Treatment with compounds (la), (lb), (Id) and (If) promote root length in Arabidopsis seedlings under osmotic stress.

[0239] To determine the role of compounds (la), (lb), (Id) and (If) in the response to osmotic stress, an analysis of was conducted in Arabidopsis seedlings following the methods described in MM.5.

[0240] Arabidopsis seedlings were subjected to osmotic stress by transferring them to sorbitol- containing media containing each of the compounds (la), (lb), (Id) and (If), or without treatment (WT). The level of inhibition in roots growth in sorbitol was quantified after 4 days. Results showed that seedlings in the presence of compounds exhibited a lower level of root growth inhibition mediated by osmotic stress compared to the untreated seedlings (FIG. 7 and FIG. 8). These seedlings displayed longer roots compared to the control (with no treatment). A significantly lower level of inhibition in shoots growth under osmotic stress was observed in pre-treated seedlings with compounds in contrast to the non-treated seedlings. In addition to the protection effect against osmotic stress, in control conditions, both compounds promote shoots and roots growth by increasing 11.7% root growth for compound (la), 22.7 % increase for compound (lb), 18% for (Id) and 12.4% for (If) compared to the WT. Boxplots in FIG. 8 depict the distribution of 7-day-old root lengths in untreated media (solid border) or sorbitol (dotted border) conditions. The trendline depicts relative root growth inhibition upon stress (ratio sorbitol / control). Different letters represent significant differences (p-value < 0.05). Data from 2 independent biological replicates (n > 30).

[0241] Example 6: Foliar application of compounds of the invention confers drought tolerance in Arabidopsis mature plants.

[0242] To further investigate if the protection effect of compounds (la) and (lb) against abiotic stress observed in seedlings is preserved in mature plants, Arabidopsis adult plants were treated with the compounds and exposed to severe drought following the methods described in MM.6. Improved drought tolerance can be determined by comparing the drought tolerance of a plant according to the invention with the drought tolerance of a wildtype plant during or after a drought period or during or after a period of reduced water availability. Results show that foliar treatment with 2 pM of compounds (la) and (lb) in three-week-old Arabidopsis plants enhanced the capacity of plant survival after a severe drought period of 12 days (up to 83%) compared to the non-treated controls (36%) (FIG. 9). The plants sprayed with compound (la) achieved 83% of survival rate, followed by compound (lb) with 55% survival rate. The time course of photosynthesis parameters (Fv / Fm) at the beginning and the end of the stress period, as well as the recovery period, indicated that the treated plants were healthier, and they even reached initial photosynthesis levels during the recovery (FIG. 10 and 11). Altogether, the results indicate that the treatment of mature plants with compounds (la) and (lb) offers protection against a stress period of 12 days in severe water withholding regime ( / .e., drought) (FIG. 12) shows phenotype differences between non-treated plants and those treated with compounds of the invention, and even enables recovery of pre-stress physiological parameters in a short period (1-2 weeks). Data were retrieved from 3 independent biological replicates (n > 40). Different letters represent significant differences (p- value < 0.05).

[0243] Example 7: Foliar application of compounds of the invention to Arabidopsis mature plants confers heat stress protection.

[0244] Heat stress protection conferred by compounds (la) and (lb) was assessed by treatment of Arabidopsis adult plants before exposing them to a period of 5 days at 42°C following the methods described in MM.7. Arabidopsis mature plants treated by foliar application with 2 pM compounds (la) and (lb) followed by a heat period of 5 days at 42°C showed a higher survival rate of up to 35% for compound (lb), followed by 25% for compound (la), compared to the non-treated plants (15%) (FIG. 13). In addition, treated plants showed higher levels of photosynthesis rate (Fv / Fm) compared to the non-treated plants during the recovery rate, indicating a better performance during stress conditions (FIG. 14) Overall, foliar application of compounds (la) and (lb) to Arabidopsis mature plants confers protection against a heat episode of 42°C during a period of 5 days. Data was retrieved from 3 independent biological replicates (n > 40). Different letters represent significant differences (p-value < 0.05).

[0245] Example 8: Foliar application of compounds of the invention to commercial tomato mature plants confers drought stress protection.

[0246] The protection effect provided by compounds (la), (lb), (Id) and (If) in abiotic stress was determined in tomato as a crop model. A drought assay was performed in the commercial cultivar of tomato cv. "Marmande" in an early vegetative stage following the methods described in MM.8. An adaptation to drought stress may be seen, for instance, as a change in biomass production, such as seed production, grain size and / or root length, which not only denotes resistance to the abiotic stress but moreover an increase in growth and development of the plant. Foliar treatment with 2pM of compounds (la), (lb), (Id) and (If) was provided to vegetative developmental stage of tomato plants (two-week-old) in two consecutive treatment days. Plants were grown with a period of 15 days without irrigation and physiological parameters were followed during this period and the recovery phase (re-water).

[0247] Results show that foliar treatment in two-week-old tomato plants enhance the capacity of plant survival up to 80% after a severe drought compared to the control (non-treatment) (FIG. 15 and 16). After a recovery period, growth rate was measured, showing that treated plants have a faster recovery compared to the non-treated plants, with a higher effect for compound (If). Photosynthesis parameters (Fv / Fm) were measured at day 0 and 3 of the stress period (FIG. 17). The results indicate that treated plants were healthier, reaching higher photosynthesis levels during the stress period (FIG. 18, where boxplots represent the median and interquartile range (IQR) and different letters represent significant differences (p-value < 0.05)). Treated plants reached from 25 to 50% stem length compared to the non-treated tomato plants during the recovery periods (FIG. 19). In terms of biomass production, treated plants with compounds increased biomass production from 2X up to 4X for compound (la) (FIG. 20). Altogether, the results indicate that the protective effect of the compounds to a two-weeks period of severe drought can be extended to crops such as tomato with spray application in a vegetative stage. Data were retrieved from 3 independent biological replicates (n > 40).

[0248] Example 9: Stomata regulation in tomato “Marmande” treated with compounds of the invention.

[0249] Stomata regulation by compounds was assayed following MM9. Results show that a short-period incubation with compounds (la) and (lb) promote the closure of stomata in tomato “Marmande” treated plants (FIG. 21 and 22) indicating that can effectively regulate stomatai closure to have higher water use efficiency.

[0250] Example 10: Hydrotropic sensitivity of primed Arabidopsis seedlings by compounds of the invention under osmotic stress.

[0251] Hydrotropism forms part of the drought-avoidance plant response. Roots are able to sense differences in water availability and bend with different curvature angles to avoid low water potential. The angle indicates the strength of the hydrotropism response. Root curvature distribution (%) in Arabidopsis seedlings (7-day-old roots) was measured after 24h of sorbitol-induced osmotic stress (270 mM) WT without (control) and with compounds (la), (lb), (Id) and (If) (FIG. 23) in a concentration of 0.5 pM. The treatments with (la), (lb), (Id) and (If) in WT seedlings regulates the hydrotropism response. The root curvature with compounds showed an increase in root curvature (as measured by the angle respect the vertical) compared to the non-treated roots (37%, 35%, 40%, and 41 %) for (la), (lb), (If) and (Id) respectively. FIG. 23 shows discrete distribution of root hydrotropic curvature angles in the different treatments. Different letters indicate a significant difference (p-value < 0.05) in a one-way ANOVA test plus Tukey’s HSD test. Boxplots represent the median and interquartile range (IQR). Whiskers depict Q1 - 1 ,5*IQR and Q3 + 1 ,5*IQR and points experimental observations. Data were retrieved from four independent biological replicates (n >45).

[0252] Example 11 : Foliar application of the compounds of the invention confers cold stress protection in Arabidopsis

[0253] Arabidopsis adult plants were treated with the compounds of the invention and were then exposed to cold stress following the methods described in MM. 10. After the 7-day recovery period, survival rate and photosynthesis parameters were measured.

[0254] Results show that foliar treatment with 2 pM of compounds (la) and (lb), separately, in three-week-old Arabidopsis plants, enhanced the capacity of plant survival (of up to 83%) after a cold stress period of 16h at -6°C when compared to the non-treated controls (36%) (FIG. 24 and 25). The plants sprayed with compound (la) achieved 70% of survival rate whereas for compound (lb) the survival rate reached 75%. The time course of photosynthesis parameters (Fv / Fm) during the recovery period, indicated that the treated plants were healthier, and they even reached initial photosynthesis levels during the recovery (FIG. 26). Altogether, the results indicate that the treatment of mature plants with compounds (la) and (lb) offers protection against a stress period of 16h at -6°C and even enables recovery of pre-stress physiological parameters in a short period (3 days). Data were retrieved from 2 independent biological replicates (n > 40). Different letters represent significant differences (p-value < 0.05).

[0255] Example 12: Treatment with compound (li), (II), (Im), (In), (Ip), (Iq), (It), (ly), (Iz), (laa), (lab), (laf), (Ih) , (lj) , (Ik) ,(lu) ,(lv), (lx), (lac), (lad), and (lae) in seedlings promote growth under heat stress in Arabidopsis.

[0256] Plants were cultivated for a period of six days on agar media, with the media supplemented with 5 pM of compounds (li), (II), (Im), (In), (Ip), (Iq), (It), (ly), (Iz), (laa), (lab), (laf) or 50 pM of compounds (Ih), (Ij), (Ik), (lu), (Iv), (lx), (lac) , (lad), and (lae) at (50 pM). Simulate elevated suboptimal temperature was tested (Rivero, et al., 2014). The results showed that these compounds have a protective effect against the adverse effects of high-temperature exposure without compromising overall growth. In a WT background at 28 °C treatment with compounds promote growth rate of the hypocotyl compared to growing in media without addition of compounds. There is an increase of the hypocotyl length up to 130% for compound (lx), followed by 50% for (Ik) at 50 pM. The increase for compounds at 5 pM is between 5-35% range depending on the compound with compound (II) reaching the highest difference (FIG. 27 and FIG. 28-29). This experiment was performed in triplicate, following the methods described in MM1 Data for FIG. 28-29 were retrieved from three independent biological replicates (n>80 per replicate).

[0257] Example 13: Sorghum cereal treated by seed immersion with compounds of the invention showed enhanced seedling development and growth.

[0258] The impact of compounds compound (Ip), (Iq), (II), (Ij), (ly), (lad), (Iz), (laa), (Iv) and (lac) on germination rate and seedling growth was assessed in sorghum seeds as cereal model following the methods described in MM.2. Four-day-old seedlings of sorghum were germinated in water (control) or supplemented with 1 pM of each compound (Ip), (Iq), (II), (Ij), (ly), (lad), (Iz), (laa), (Iv) and (lac). Sorghum seeds exposed to compounds of the invention exhibited notable acceleration in seedling development during a period of 4 days leading to an increase in overall seedlings growth (FIG. 30) and an increase in germination rate reaching up to 10% higher than untreated for compounds (Ij), (Ik), (laa) and (lu). The phenotype of root length revealed a significant effect on promoting root growth. Compound (laa) exhibited a remarkable performance by promoting root length up to 2X compared to non-treated followed by compounds ((Ij), (ly) and (II) that increase root growth in the range of 25-35% compared to the untreated (FIG. 31-33). Boxplots depict the distribution of 4-days-old root length of control (untreated) and 1 pM compounds (Ip), (Iq), (II), (Ij), (ly), (lad), (Iz), (laa), (Iv) and (lac) treatment. Boxplots represent the median and interquartile range (IQR). Different letters represent significant differences (p- value < 0.05). Data were retrieved from three independent biological replicates (n > 60). The incubation of seeds with the compounds of the invention did not show any indications of toxicity on seedling development. In addition, these compounds demonstrated a beneficial effect by significantly promoting seedling development and fostering a notable root growth rate in sorghum. In summary, this study underscores the non-toxic and high beneficial impact of these compounds on seedling development in sorghum.

[0259] Example 14: Fertirrigation application of compounds of the invention to commercial tomato mature plants confers drought stress protection. The protection effect provided by compounds (Iz), (laa), (Ip), (Iq), (II), (Iv), (lx), (lab), (lac), (Ij), (Ik), (ly), (lad), (It) and (lu) in abiotic stress was determined in tomato as a crop model. A drought assay was performed in the commercial cultivar of tomato cv. "Marmande" in an early vegetative stage following the methods described in MM.3. An adaptation to drought stress may be seen, for instance, as a change in biomass production, such as seed production, grain size and / or root length, which not only denotes resistance to the abiotic stress but moreover an increase in growth and development of the plant. Fertirrigation treatment with 1 pM of compounds compounds (Iz), (laa), (Ip), (Iq), (II), (Iv), (lx), (lab), (lac), (Ij), (Ik), (ly), (lad), (It) and (lu) was provided to vegetative developmental stage of tomato plants (two-week-old). Plants were grown with a period of 11-13 days without irrigation and physiological parameters were followed during this period and the recovery phase (rewater).

[0260] Results show that compound treatments applied to a two-week-old tomato plants enhance the capacity of plant survival up to 87% for compound (lu) after a severe drought compared to the control (non-treatment) (FIG. 34 and FIG 35). In terms of biomass production, treated plants with compounds increased biomass production up to 4X in root biomass for compound (laa) and up to 3X in aerial biomass for compound (Iv) (FIG. 36). Treated plants reached up to 22% increase in plant height for compounds (lu) and (Iv) compared to the non-treated tomato plants during the recovery periods (FIG. 37). Altogether, the results indicate that the protective effect of the compounds to protect plants from a period of severe drought which can be extended to crops such as tomato with application as primming in vegetative stage. Data were retrieved from 3 independent biological replicates (n > 40).

[0261] Citation List

[0262] Patent Literature

[0263] - US5604177

[0264] - WO2015177215A1

[0265] - WO2022253967A2

[0266] - US20160102042A1

[0267] Non-Patent Literature

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Claims

Claims1 . Use of a compound of formula (I) or any stereoisomer or mixture thereof, or an agriculturally acceptable salt of any of them, to increase growth and / or yield of a plant, at any developmental stage, as compared to the non-treated plant of the same species and at the same developmental stage,wherein:X is C; n is an integer from 0 to 3; is a bond;R1 and R2 are radicals independently selected from H, halogen, OH, NH2, SH, (Ci-Cs)- alkyl, (Ci-C6)-alkenyl, O-(Ci-C6)-alkyl, and (Ci-C6)-alcohol, or alternatively, and R1 and R2 form together a C=O double bond, being n =1 ;R3 is a radical selected from H, halogen, OH, NH2, SH, (Ci-C3)-alkyl, (Ci-C3)-alkenyl, O- (Ci-C3)-alkyl, (Ci-C3)-alcohol, and (Ci-C3)-carboxylic acid;R4 is a radical selected from H, halogen, OH, NH2, SH, (Ci-C3)-alkyl, (Ci-C3)-alkenyl, O- (Ci-C3)-alkyl, and (Ci-C3)-alcohol;Rs is a radical selected from H, halogen, OH, NH2, SH, (Ci-C6)-alkyl, (Ci-C6)-alcohol, (Ci- C3)-alkyl (C1-C3) carboxylate, O-(Ci-C6)-alkyl, NH-(Ci-C6)-alkyl, and S-(Ci-C6)-alkyl; or alternatively,R4'• Rs together with the atoms to which they are attached form a feasible 5 to 7- membered ring, yielding to a compound of formula (h),wherein:Ri and R2 have the same meaning as in formula (I);A-D are independently selected from the group consisting of CH2, CH, NH, N, O, S, NCH3 and N-CO-CH3; m and o are integers independently selected from 0 to 1 ; the feasible 5 to 7-membered ring is selected from an aromatic carbocycle, an aromatic heterocycle, a non-aromatic carbocycle, and a non-aromatic heterocycle; the aromatic and the non-aromatic heterocycle rings have from 1 to 3 heteroatoms;R6-R9 in formula (I) and formula (h) are radicals independently selected from H, halogen, OH, NH2, NO2, SH, (Ci-C6)-alkyl, (Ci-C6)-alcohol, (Ci-C3)-alkyl (C1-C3) carboxylate, O-(C Ce)-alkyl, NH-(Ci-Ce)-alkyl, S-(Ci-Ce)-alkyl, or alternatively, two adjacent R6-R9 together with the carbon atom to which are attached form a membered ring selected from an aromatic carbocycle, an aromatic heterocycle, a non-aromatic carbocycle, and a non- aromatic heterocycle; and Rwin formula (I) and (h) is a radical independently selected from H or (Ci-Ce)-alkyl.

2. Use according to claim 1 , wherein R1 and R2 are radicals independently selected from H, halogen, OH, NH2, SH, (Ci-C6)-alkyl, (Ci-C6)-alkenyl, O-(Ci-C6)-alkyl, and (Ci-C6)- alcohol;Re-Rg in formula (I) and formula (h) are radicals independently selected from H, halogen, OH, NH2, SH, (Ci-Ce)-alkyl, (Ci-C6)-alcohol, (Ci-C3)-alkyl (C1-C3) carboxylate, O-(Ci-Ce)- alkyl, NH-(Ci-Ce)-alkyl, and S-(Ci-Ce)-alkyl; andR10 is H, and when R4 '• Rs together with the atoms to which they are attached form a feasible 5 to 7-membered ring, yielding to a compound of formula (h), A-D are independently selected from the group consisting of CH2, CH, NH, N, O, S, NCH3.

3. Use according to any of the claims 1-2, wherein Re and Rg are H.

4. Use according to any of the claims 1-3, wherein R? and Rs are radicals independently selected from H, OH, (Ci-Ce)-alkyl, and O-(Ci-Ce)-alkyl.

5. Use according to any of the claims 1-4, wherein R3 is a radical selected from H, (C1-C3)- alkyl, and (Ci-C3)-carboxylic acid.

6. Use according to any of the claims 1-5, wherein n is 1 and Rs is COOH.

7. Use according to any of the claims 1-6, wherein the compound of formula (I) is selected from the following list:2-(2-methylphenyl)butanedioic acid (la);2-(2-methoxyphenyl)butanedioic acid (lb);2-(3,4-dihydroxyphenyl)propanoic acid (Ic);1 ,2,3,4-tetrahydro-1-isoquinolinylacetic acid (Id);2-(1 ,2,3,4-tetrahydroisoquinolin-1-yl)propanoic acid (le);3-(3,4-dihydroxyphenyl)propanoic acid (If);3-(4-hydroxyphenyl)-2-oxopropanoic acid (Ih);3-(4-hydroxyphenyl)butanoic acid (li);3-(4-methoxyphenyl)propionic acid (Ij);3-(3-methoxyphenyl)propionic acid (Ik);3-(2-hydroxyphenyl)propionic acid (II);3-(3-hydroxy-4-methoxyphenyl)propionic acid methyl ester (Im);3-(3-hydroxy-4-methoxyphenyl)propionic acid (In);3-(4-hydroxyphenyl)propionic acid (Io);(3S)-3-Phenylbutyric acid (Ip);(3R)-3-Phenylbutyric acid (Iq); phenylsuccinic acid (It);2,3-dimethyl-2-phenylsuccinic acid (lu);(2-(4-methoxyphenyl)butanedioic acid) (Iv);2-(2-chlorophenyl)butanedioic acid (lx);2-(4-nitrophenyl)succinic acid (ly);6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolin-1-yl acetic acid (Iz);6-methoxy-1,2,3,4-tetrahydroisoquinolin-1-yl acetic acid (laa); methyl 2-(1 ,2,3,4-tetrahydroisoquinolin-1-yl)acetate (lab);2-(2-acetyl-1 ,2,3,4-tetrahydroisoquinolin-1-yl)acetic acid (lac);I , 2, 3, 4-tetrahydro-isoquinoline-1 -carboxylic acid (lad);3-(4-hydroxyphenyl)-2-hydroxypropanoic acid (lae); and 3-(1 ,3-benzodioxol-5-yl)-2-methylpropanoic acid (laf).

8. Use according to any of the claims 1-7, wherein the plant is a plant subject to an abiotic stress, and the use further comprises an increase in the adaptability of the plant to an abiotic stress.

9. Use according to claim 8, wherein the abiotic stress is selected from the group consisting of heat stress, drought stress, cold stress and osmotic stress.

10. Use according to any of the claims 1 -7, wherein the plant is a plant subject to a biotic stress, and the use further comprises an increase in the adaptability of the plant to an biotic stress.I I . Use according to any of the claims 1-10, wherein the plant is a mature plant.

12. Use according to claim 11, wherein the compound of formula (I) is applied to the mature plant by foliar application.

13. Use according to any of the claims 1-10, wherein the plant is a seed or a seedling.

14. Use according to claim 13, wherein the compound of formula (I) is applied to the seed or seedling by immersion, coating, incubation and / or supplementation.

15. Use according to any of the claims 1-14, wherein the plant family is selected from Brassicaceae, Poaceae, and Solanaceae.

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