Use of resin acid as defensive gene inducer for biological stress in plants

Abstract

The present invention relates to the use of a resin acid as a defensive gene inducer for biological stress in plants. The invention also relates to a composition comprising rosin and its use as a defensive gene inducer for biological stress in plants.

Description

Field of the Invention

[0001] The present invention relates to the use of resin acids as inducers of defense genes in plants. The present invention also relates to compositions comprising rosin and their use as inducers of defense genes against biotic stress in plants. Background of the Invention

[0002] Today, there is an increasing concern about environmental issues and a desire to protect our planet, especially in the agricultural field. However, the infestation of crops by pests is very serious, causing huge economic losses to the agricultural sector. In particular, pests such as fungi and / or oomycetes are viral to grapevines. If left untreated, the invasion of grape downy mildew (GDM) can lead to yield losses and a reduction in grape quality.

[0003] A common solution to minimize damage during the growing season is to repeatedly spray chemical pesticides on crops.

[0004] Among these pesticides, copper-based fungicide compositions are commonly used in conventional, integrated, and organic agriculture to control devastating plant diseases such as grape downy mildew, potato and tomato late blight, apple scab, and a wide range of other plant pathogens. In particular, Bordeaux mixture is commonly used as a control agent against grape downy mildew. This disease is caused by the fungus or oomycete Plasmopara viticola.

[0005] Since 2006, the use of copper has been restricted by European Commission regulations due to its toxicity to the environment. Despite its adverse ecotoxicological properties, the use of copper is still permitted due to its unique properties as a broad-spectrum fungicide and bactericide, especially against grape downy mildew.

[0006] Although this strategy can control the damage level at a relatively low level, it has serious environmental consequences, high production costs, and poses risks to human health, especially for grape growers. In addition, these substances may have an adverse impact on the wine-making process and thus affect the quality of wine.

[0007] Organic vineyards use copper-based fungicides to control diseases.

[0008] The control of pathogens using plant-derived plant protection products is an effective, sustainable, and environmentally friendly pest management method in integrated pest management (IPM) and organic agricultural systems. Natural organic compounds are usually easily degraded in the natural environment, for example, by ultraviolet light, and are therefore less likely to accumulate in the environment or leave residues on food.

[0009] Recent studies have shown that resin acid derivatives and phenolic compounds such as stilbenes, flavonoids, and lignans have fungicidal properties. In particular, Savluchinske-Feio et al. (1) found that the antimicrobial activity of resin acid derivatives is expressed by killing microorganisms and / or restricting their growth. This study focused on revealing the inhibitory concentrations IC50 or IC100 of different derivatives but did not mention the activity of resin acid on defense genes.

[0010] Gabaston et al. (2, 3) have demonstrated that stilbene-rich extracts from grape (Vitis vinifera) waste (vines, xylem, and roots) and common spruce bark are highly effective against grape downy mildew caused by the fungus or oomycete Plasmoparaviticola.

[0011] Alternative solutions for protecting crops from diseases rely on the use of elicitors to enhance plant resistance to pathogens. Elicitors are natural or synthetic compounds that can induce the defense response of plants after pathogen infection. They stimulate the defense activities of plants. Elicitors are non-specific and vary greatly in their chemical nature, including proteins, oligosaccharides, glycoproteins, and lipids.

[0012] Therefore, there is a need to provide non-toxic, highly effective, economical, and eco-friendly phytosanitary products to protect crops from fungal damage.

[0013] In particular, there is a high interest in providing alternative or complementary compositions to copper-based fungicides that can reduce the use of copper for preventing or treating diseases caused by fungi and / or oomycetes in plants. Summary of the Invention

[0014] The present disclosure relates to the use of resin acid as an inducer of defense genes against abiotic and / or biotic stress in plants. Specifically, the present invention relates to the use of resin acid as an inducer of defense genes against biotic stress in plants.

[0015] The present invention also relates to a composition comprising rosin and a solvent.

[0016] The present disclosure relates to the use of resin acid as a biostimulant or a phytosanitary product. Specifically, the present invention also relates to the use of resin acid as a phytosanitary product.

[0017] The present disclosure relates to the use of a composition comprising rosin as an inducer of defense genes against abiotic and / or biotic stress in plants. Specifically, the present invention also relates to the use of a composition comprising rosin as an inducer of defense genes against biotic stress in plants.

[0018] The present disclosure also provides a method for treating or preventing diseases in plants caused by at least one fungus and / or oomycete, the method comprising step (i): applying to the plant a composition comprising rosin. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A summary of the identified relevant proteins and pathways is illustrated to explain the effect of the rosin composition of the present invention on grape leaves. DETAILED DESCRIPTION

[0020] DEFINITIONS

[0021] For the purposes of the present invention, a "defense gene inducer" refers to the induction of gene expression representing the main defense pathways in plants - from defense proteins (pathogenesis-related proteins) to signaling pathways (salicylic acid, jasmonic acid, and ethylene).

[0022] For the purposes of the present invention, a "pine stump" refers to the remaining part of the trunk of a pine tree (with the roots still underground) after the pine tree has been cut down.

[0023] For the purposes of the present invention, a "biostimulant" refers to a substance that stimulates plant nutritional processes independently of the nutrients it contains, with the aim of improving one or more of the following characteristics of the plant or its rhizosphere: nutrient use efficiency, abiotic stress tolerance, quality characteristics, availability of nutrients in the soil or rhizosphere (in accordance with EU Regulation 2019 / 1009).

[0024] Biostimulants can be certain harmless natural preparations (PNPP). PNPP are:

[0025] - Natural substances for biostimulants (NSPB) or

[0026] - Basic substances.

[0027] The definition of basic substances is given in Article 23 of Regulation (EC) 1107 / 2009. These substances have phytosanitary significance, but their main use is not plant protection (e.g., food).

[0028] In the context of the present invention, the term "biotic stress" refers to stress resulting from damage to plants caused by living organisms (e.g., plant pathogens). The term "pathogen" refers generally to all pathogens of plants, such as bacteria, viruses, fungi, parasites, or insects. More preferably, the pathogen is a fungal pathogen, such as a fungus and / or oomycete.

[0029] In the context of the present invention, the term "abiotic stress" refers to stress resulting from damage to plants caused by abiotic environmental factors (e.g., drought, extreme cold or heat, strong winds, salinity, heavy metals). DETAILED DESCRIPTION OF THE INVENTION

[0031] The present invention concerns the use of resin acids as inducers of defense genes against biotic stress in plants.

[0032] The present invention also relates to the use of resin acids as phytosanitary products.

[0033] Specifically, the resin acids disclosed herein have activity against at least one fungus and / or oomycete.

[0034] Surprisingly, the applicant has found that resin acids can induce plant defenses and thus can be used as inducers of defense genes against biotic stress to combat pathogens.

[0035] Therefore, resin acids can be classified into the category of elicitor or triggering molecules.

[0036] Examples of the present invention show that the use of resin acids derived from or contained in rosin can reduce the invasion of fungi and / or oomycetes, especially the invasion of vine mildew (severity and frequency) in field trials.

[0037] Advantageously, the composition containing rosin is particularly effective in preventing fungal damage and treating fungal diseases in plants.

[0038] Notably, the combination of the compositions disclosed herein with low-content copper-based compositions is as effective as conventionally used copper-based fungicides.

[0039] Therefore, the fungicidal compositions based on resin acids derived from or contained in rosin disclosed herein can reduce the amount of copper-based fungicides used in vineyards.

[0040] Resin Acids

[0041] The present invention relates to resin acids and their ability to induce plant defenses. The term "resin acid" should be understood to mean any compound or mixture obtained or derived from wood and containing a carboxylic acid functional group and a fused tricyclic group. The resin acids are tricyclic diterpene monocarboxylic acids or are derived from tricyclic diterpene monocarboxylic acids. Resin acids include acids from abietic-type acids, primaric-type acids, and other acids (such as communic acid or mercusic acid). Specifically, the present invention relates to resin acids from abietic-type acids and their ability to induce plant defenses.

[0042] Examples of resin acids include, but are not limited to, abietic acid, levopimaric acid, palustric acid, neoabietic acid, dehydroabietic acid, isopimaric acid, pimaric acid, levopimaric acid, sandaracopimaric acid, pinus elliottii var. elliottii acid, oxidized resin acid, dimerized resin acid, polymerized resin acid, or mixtures thereof.

[0043] According to any embodiment of the present invention, the resin acid is in the form of a mixture that contains at least one acid selected from dehydroabietic acid, abietic acid, pimaric acid, dimerized resin acid, polymerized resin acid, and mixtures thereof. Specifically, the resin acid is in the form of a mixture that contains at least one acid selected from dehydroabietic acid, dimerized resin acid, polymerized resin acid, and mixtures thereof.

[0044] The resin acid is preferably derived from or contained in rosin.

[0045] Rosin

[0046] Rosin, also known as colophony, is typically obtained from coniferous trees, particularly pine trees.

[0047] Rosin is a type of resin that is solid at room temperature.

[0048] It is typically produced by heating liquid resin to evaporate volatile liquid terpene components.

[0049] Rosin mainly consists of resin acids (such as those listed above).

[0050] The softening point and acid number of rosin are key quality parameters.

[0051] The softening point can be determined by measuring the glass transition temperature of rosin. The softening point of rosin is determined according to methods well known to those skilled in the art, particularly according to the procedure described in patent WO2022 / 133426.

[0052] The softening point of rosin according to the present invention is typically 50 °C to 175 °C, preferably 60 °C to 140 °C, preferably 75 °C to 125 °C, more preferably 80 °C to 120 °C.

[0053] Depending on its use, rosin may need to be softened, for example, for consumer products or during storage. The value of the softening point will affect the properties of rosin.

[0054] The acid value, also known as the "acid number", is used to quantify the amount of acid present in rosin. The acid value of rosin is determined according to methods well known to those skilled in the art, in particular according to the procedure described in patent WO2022 / 133426.

[0055] This acid value can be less than about 175, for example about 50 to about 175, preferably 90 to 170, preferably 100 to 170 or 90 to 140, preferably 110 to 170 or 90 to 130, preferably 120 to 170 or 90 to 130, preferably 130 to 170 or 90 to 130, preferably 140 to 170 or 90 to 130, even more preferably 150 to 170 or 90 to 130.

[0056] Rosin is a solid form of turpentine resin from pine trees and is obtained by cutting the bark. Distillation of turpentine resin can produce a volatile fraction mainly composed of terpenes and a non-volatile solid fraction corresponding to rosin.

[0057] Rosin can be solid at room temperature, translucent, and its color ranges from light yellow to dark brown, or even black.

[0058] Suitable sources of rosin include gum rosin, wood rosin, tall oil rosin, their derivatives, or mixtures thereof.

[0059] Preferred sources are wood rosin, gum rosin, and their derivatives.

[0060] Gum rosin can be from resin exudates of trees or other plants and can be harvested by cutting or wounding the trees and then collecting and processing the exudates.

[0061] Tall oil rosin is a by-product of the distillation of crude tall oil in the kraft pulp production process for pine pulp.

[0062] Wood rosin can be from materials harvested from pine trees (especially pine stumps), for example by solvent extraction and / or distillation.

[0063] Advantageously, these resins are sticky and waterproof, and thus can be induced more effectively.

[0064] According to a specific embodiment, the preferred rosin is gum rosin, especially gum rosin derivatives. The term "gum rosin derivatives" refers to chemically modified gum rosin; for example, gum rosin can be further hydrogenated, dehydrogenated, disproportionated, esterified, dimerized, polymerized. In particular, the preferred rosin is disproportionated gum rosin or dimerized gum rosin. Conditions applicable to gum rosin derivatives are well known to those skilled in the art.

[0065] According to another specific embodiment, the preferred rosin is gum rosin.

[0066] In some embodiments, the rosin is gum rosin extracted from pine trees, especially pine stumps.

[0067] In some embodiments, the rosin is gum rosin extracted from pine trees, provided that the gum rosin is not extracted from knots.

[0068] Advantageously, these resins are sticky and rain - proof, and thus can be induced more effectively.

[0069] According to any embodiment of the present invention, the rosin is gum rosin or disproportionated gum rosin or dimerized gum rosin extracted from pine trees, and the rosin contains dehydroabietic acid (CAS No. 1740 - 19 - 8). The disproportionated gum rosin is gum rosin treated with a catalyst (such as palladium in metallic form, Pd / C, platinum in metallic form, Pt / C, nickel in metallic form, Ni / C or iodine). Dismutation is also known as disproportionation. The dimerized gum rosin is gum rosin treated with a Bronsted acid (such as sulfuric acid or formic acid) or a Lewis acid (such as BCl 3 、BF 3 or ZnCl 2 ).

[0070] In some embodiments, the applicant has also demonstrated that gum rosins sold, for example, under the names MC, and etc. can induce defense genes in grapevines against biotic stress.

[0071] MC and are three resins produced from pine stump extracts by Pinova, registered according to the Reach regulation, and their CAS numbers are the same as those of gum rosin, i.e., 8050 - 09 - 7.

[0072] Gum rosin contains resin acids as described above, which have been proven in the present invention to be able to induce defense genes in plants against biotic stress.

[0073] Suitable rosins include any rosin registered according to the Reach regulation, with a CAS number of 8050 - 09 - 7 (corresponding to gum rosin) or a CAS number of 65997 - 05 - 9 (corresponding to polyrosin). Non - limiting examples of commercially available rosins include but are not limited to Vinsol and sold by Pinova or Resigral 140 sold by DRT and 95

[0074] Typically, rosin is obtained from pine trees of the genus Pinus. The pine trees are preferably selected from the following species:

[0075] - Aleppo pine or Jerusalem pine (scientific name: Pinus halepensis)

[0076] - Calabrian pine or Turkish pine or Persian pine (scientific name: Pinus brutia)

[0077] - Macedonian pine or Balkan pine (scientific name: Pinus peuce)

[0078] - Maritime pine or Landes pine (scientific name: Pinus pinaster)

[0079] - Mountain pine or mugo pine, Pinus mugo, Black pine (scientific name: Pinus nigra)

[0080] - Stone pine, Scots pine (scientific name: Pinus sylvestris)

[0081] - Lodgepole pine (Pinus contorta)

[0082] - Siberian pine (Pinus sibirica)

[0083] - Monterey pine (scientific name: Pinus radiata)

[0084] - Frankincense pine (scientific name: Pinus taeda)

[0085] - Jack pine (scientific name: Pinus banksiana)

[0086] - Caribbean pine (scientific name: Pinus caribaea)

[0087] - Pinus tecunumanii

[0088] - Ponderosa pine (scientific name: Pinus ponderosa)

[0089] - Slash pine (scientific name: Pinus elliottii)

[0090] - Bosnian pine (scientific name: Pinus heldreichii, synonym: Pinus leucodermi)

[0091] - Canary Island pine (scientific name: Pinus canariensis)

[0092] - Cembro pine (scientific name: Pinus cembra)

[0093] - Longleaf pine (scientific name: Pinus palustris)

[0094] Preferably, rosin is obtained from pine tree species of Pinus palustris, Pinus pinaster, and Pinus elliottii.

[0095] According to a specific embodiment, wood rosin is extracted from pine stumps of the genus Pinus. Specifically, wood rosin is extracted from pine stumps of the species Pinus palustris and Pinus elliottii.

[0096] Wood rosin is generally obtained from pine stumps through traditional extraction processes. For example, wood rosin can be obtained by hot water extraction, subcritical water extraction, water / organic solvent mixture extraction, water / alcohol solvent mixture extraction, or extraction with at least one organic solvent.

[0097] Preferably, the extract is obtained by extraction with a water / organic solvent mixture or by extraction with at least one organic solvent.

[0098] Any organic solvent mixture existing in such extraction processes can be used for the purposes of the present invention.

[0099] Non-limiting examples include hydrocarbon solvents such as hexane, cyclohexane, heptane, octane, or ether solvents such as methyltetrahydrofuran, alcohol solvents such as methanol, ethanol, propanol, 2-methylbutan-2-ol or mixtures thereof, ester solvents such as n-butyl acetate, isopropyl acetate, ethyl acetate, or ketone solvents such as acetone, acetophenone, butanone, cyclopentanone, or mixtures thereof.

[0100] In some embodiments, the rosin contains 15 to 95% by weight of resin acids, particularly 20 to 85% by weight, particularly 40 to 80% by weight, particularly 60 to 80% by weight, or 40 to 75% by weight, more preferably 65 to 75% by weight, based on the total weight of the rosin. In a particular embodiment, the rosin contains at least 85% by weight of resin acids based on the total weight of the rosin.

[0101] In some embodiments, the rosin contains at least 30% by weight of dehydroabietic acid, particularly 40% by weight, particularly at least 45% by weight, more preferably at least 50% by weight, based on the total weight of the rosin.

[0102] In some embodiments, the rosin contains at least 20% by weight of dimer resin acids, particularly at least 30% by weight, more particularly at least 35% by weight, based on the total weight of the rosin.

[0103] The rosin disclosed herein may also contain flavonoids, stilbenes, dimethoxystilbene, waxes, polyterpenes, lignans, and lignan degradation products such as phenolic derivatives.

[0104] Examples of flavonoids include pinocembrin.

[0105] Typically, the stilbenes are selected from the group consisting of pinosylvin monomethyl ether and pinosylvin dimethyl ether.

[0106] Examples of lignans or lignan degradation products include nortrachelogenin, phlobaphenes, carboxylated phlobaphenes, lignin hydroxylactone.

[0107] Preferably, the rosin is gum rosin extracted from pine stumps or disproportionated gum rosin or dimerized gum rosin, and is used as an inducer of defense genes against total biotic stress in plants.

[0108] In some embodiments, the plant is a crop.

[0109] Non-limiting examples of the plant include grapevine, vegetables such as tomato plants, potato plants, lettuce, cucurbitaceous plants such as melons, and cereals such as wheat, barley, oats, and rye.

[0110] Preferably, the plant is selected from the group consisting of grapevine and cereals.

[0111] In some embodiments, the defense gene is a gene encoding an enzyme in the phenylpropanoid pathway or a pathogenesis-related protein.

[0112] More specifically, rosin can be used to enhance defense genes selected from pathogenesis-related proteins, phenylpropanoids, isoprenoids, oxidative stress, parietal modifications, and signaling pathways such as salicylic acid, jasmonic acid, and ethylene.

[0113] Plants are not only subject to biotic stresses such as pathogen infections, but also to abiotic stresses such as cold, heat, drought, and salinity. Plants adopt adaptive strategies to avoid or mitigate these adverse effects. Fatty acids and reactive oxygen species (ROS) are general defenders and play a key role in the adaptation of plants to abiotic and biotic stresses. In fact, plants induce the synthesis of fatty acids to thicken their cuticle, thereby protecting themselves from dehydration or pathogen attacks. Similarly, plants also induce the synthesis of ROS to respond to ultraviolet light or fungal invasions.

[0114] As shown in the examples, proteomic analysis experiments on grapevine leaves treated with the compositions containing wood rosin disclosed herein showed an induction of the DAMP (damage-associated molecular pattern) response, including proteins that may be involved in cell wall synthesis, transport of secondary metabolites and sugars, detoxification of xenobiotics, abscisic acid receptors, and regulation of reactive oxygen species.

[0115] Therefore, the related pathways involved in the present invention include the biosynthesis of pantothenate and coenzyme A, lipid synthesis and / or cell wall synthesis, and the regulation of reactive oxygen species.

[0116] In some embodiments, rosin can be used in combination with a fungicide.

[0117] This combination is of particular interest as an alternative to treatment with a copper-based fungicide alone.

[0118] Furthermore, this combination is as effective as traditional copper-based fungicides when sprayed on plants.

[0119] Preferably, the fungicide is selected from the group consisting of: copper-based products such as copper hydroxide, Bordeaux mixture, dithiocarbamates, dicarboximides, potassium phosphonate, dipotassium phosphonate, monopotassium phosphite, disodium phosphonate, carboxamides, cyanoimidazoles, acetamides, phenylamides and benzamides, phthalimides, cyanoacetamide oxime, sulfamoyl triazoles, triazolopyrimidine amines and piperidine triazole isoxazoline.

[0120] In some preferred embodiments, the copper-based fungicide is copper hydroxide. This fungicide is sold by ActionPin under the brand name.

[0121] Rosin composition

[0122] The present invention also relates to a composition comprising rosin and a solvent as described above and its use as an inducer of defense genes against biotic stress in plants.

[0123] In some embodiments, the solvent is selected from the group consisting of: dimethyl sulfoxide (DMSO), fatty acid methyl ester, N,N-dimethyldecanamide (such as C10 fatty acid dimethylamide sold under the brand name Genagen ), 1-butylpyrrolidin-2-one sold under the brand name Genagen ), alkyl-1,2-diols with an alkyl chain having 5 to 10 carbon atoms, 2,5,7,10-tetraoxaundecane, dibutoxymethane (butylal), diethoxymethane (ethylal), bis(ethylhexoxy)methane (2-ethylhexylal) and ethyl lactate.

[0124] Typically, the composition comprises 35 to 60% by weight of the solvent, preferably 35 to 40% by weight, more preferably 36 to 40% by weight of the solvent based on the total weight of the composition.

[0125] The composition according to the present invention may further comprise an emulsifier, a penetrant and a wetting agent.

[0126] In some embodiments, the emulsifier is selected from the group consisting of: ethoxylated castor oil, ethoxylated fatty alcohols, alkyl polyglucosides, ethoxylated rapeseed oil, glycerol polyether-2-cocoate, polyethoxylated polyol esters such as Levenol Polyoxyethylene sorbitan monolaurate is also known as polysorbate or Tween 20.

[0127] Typically, the composition comprises an emulsifier in an amount of 15 to 40% by weight, preferably 20 to 30% by weight, more preferably 22 to 28% by weight, even more preferably 23 to 27% by weight, based on the total weight of the composition.

[0128] The composition may further comprise a penetrant selected from the group consisting of tall oil fatty acids, unsaturated fatty acids such as oleic acid or linoleic acid, and saturated fatty acids such as palmitic acid and stearic acid.

[0129] Generally, the composition comprises a penetrant in an amount of 1 to 15% by weight, preferably 5 to 13% by weight, more preferably 7 to 12% by weight, even more preferably 8 to 11% by weight, based on the total weight of the composition.

[0130] In some embodiments, the wetting agent is a terpene alcohol, especially the wetting agent is selected from the group consisting of 2,6-dimethyloct-7-en-2-ol, α-terpineol, 4(8)-p-menthen-1-ol, cis-3,7-dimethyl-2,6-octadien-8-ol, trans-3,7-dimethyl-2,6-octadien-1-ol, 10-hydroxymethylene-2-pinene, 3,7-dimethyloct-6-en-1-ol.

[0131] Advantageously, the use of terpenes can improve the spreading of the composition according to the invention on plants.

[0132] The composition typically comprises a wetting agent in an amount of 5 to 30% by weight, preferably 5 to 20% by weight, more preferably 6 to 15% by weight, even more preferably 7 to 12% by weight, even more preferably 8 to 11% by weight, based on the total weight of the composition.

[0133] In some embodiments, the composition comprises rosin in an amount of 15 to 25% by weight, preferably 16 to 23% by weight, more preferably 16 to 20% by weight, based on the total weight of the composition. In some embodiments, the composition comprises rosin in an amount of 17% by weight, based on the total weight of the composition.

[0134] In some preferred embodiments, the rosin is wood rosin extracted from pine stumps or disproportionated gum rosin or dimerized gum rosin.

[0135] The present invention typically provides a composition comprising a solvent in an amount of 35 to 40% by weight, an emulsifier in an amount of 20 to 30% by weight, rosin in an amount of 15 to 25% by weight, a penetrant in an amount of 1 to 15% by weight, and a wetting agent in an amount of 5 to 30% by weight, based on the total weight of the composition. In some preferred embodiments, the rosin is wood rosin extracted from pine stumps or disproportionated gum rosin or dimerized gum rosin.

[0136] Advantageously, the compositions according to the invention enhance the plant's defense against fungi and / or oomycetes.

[0137] The compositions according to the invention can be in solid or liquid form. Preferably, they are in liquid form.

[0138] In some embodiments, the compositions disclosed herein are in the form of an emulsifiable concentrate.

[0139] In some embodiments, the composition comprising rosin is provided in a form suitable for application by spraying.

[0140] Advantageously, the compositions according to the invention can reduce the dose of copper fungicide composition used on plants.

[0141] In some embodiments, the dose of copper is reduced by 20% to 50% relative to the usual dose on plants.

[0142] The composition can be prepared by conventional methods, for example by mixing different components.

[0143] The invention also relates to the use of the compositions disclosed herein as phytosanitary products.

[0144] Plant protection composition

[0145] The invention also relates to a plant protection composition comprising a rosin-based composition and a fungicide as described above.

[0146] Preferably, the fungicide is selected from the group consisting of copper-based products such as copper hydroxide, Bordeaux mixture, dithiocarbamates, dicarboximides, potassium phosphonate, dipotassium phosphite, monopotassium phosphite, disodium phosphite, carboxamide, cyanoimidazole, acetamide, phenylamide and benzamide, phthalimide, cyanoacetamide oxime, sulfamoyl triazole, triazolopyrimidine amine and piperidine triazole isoxazoline.

[0147] In some preferred embodiments, the copper-based fungicide is copper hydroxide. This fungicide is sold by ActionPin under brand.

[0148] In some preferred embodiments, the rosin is wood rosin extracted from pine stumps or disproportionated gum rosin or dimerized gum rosin.

[0149] Method

[0150] The invention also relates to a method for treating or preventing diseases in plants caused by at least one fungus and / or oomycete, the method comprising step (i): applying to the plant a composition according to the invention.

[0151] In some embodiments, the method comprises step (i): applying to the plant an effective amount of a composition according to the present invention.

[0152] The present invention can enhance the resistance of the treated plants to diseases.

[0153] The present invention also relates to a method for inducing defense genes against biotic stress in plants using resin acids.

[0154] The present invention also relates to a method for inducing defense genes against biotic stress in plants using rosin according to the present invention.

[0155] In some embodiments, the present invention also relates to a method for inducing defense genes against biotic stress in plants using a composition according to the present invention.

[0156] In some embodiments, the method of the present invention may further comprise step (ii): applying a fungicidal composition to the plant.

[0157] Preferably, the fungicidal composition contains copper.

[0158] Advantageously, the combination of the compositions disclosed herein with copper-based fungicides can reduce the amount of copper used on plants and exhibit similar activity in preventing or treating diseases caused by fungi and / or oomycetes.

[0159] Steps (i) and (ii) can be carried out simultaneously or sequentially in a certain order.

[0160] Preferably, the diseases caused by at least one fungus and / or oomycete are selected from the group consisting of grapevine downy mildew, grapevine powdery mildew, grapevine botrytis, potato and tomato late blight, apple scab, and wheat rust.

[0161] More common diseases are grapevine downy mildew, grapevine powdery mildew, grapevine botrytis, or wheat rust.

[0162] Examples of fungi and / or oomycetes include, but are not limited to: Plasmopara viticola, Phytophthora infestans, Pseudoperonospora cubensis, Bremia lactucae, Botrytis cinerea, Erysiphe necator, Uromyces sp., and Puccinia sp.

[0163] Preferably, the fungus and / or oomycete is Plasmopara viticola, which causes grapevine downy mildew.

[0164] In some embodiments, the application rate of the composition according to the invention is 0.5 to 2 liters per hectare per leafwall area, preferably 1 liter per hectare per leafwall area.

[0165] In some embodiments, the application rate of the composition according to the invention is 0.5 to 3 liters per hectare, preferably 0.8 to 2.4 liters per hectare.

[0166] On a per-application-unit basis, 0.5 liters per hectare per leafwall area is equivalent to 0.8 liters per hectare.

[0167] The dose depends on the leafwall area of the plant, which in turn depends on the row width and height of the plant.

[0168] In the present invention, the leafwall area (LWA) is calculated according to the following formula:

[0169] LWA = (2 × H × 10000) / D

[0170] where LWA is the leafwall area (m 2 / ha),

[0171] H is the height of the leafwall (m), measured vertically as the height between the lowest and highest leaves of the leafwall area, and

[0172] D is the distance measured between the rows of plants (m).

[0173] When the pest pressure is high, the rosin-based compositions disclosed herein can be used in combination with a fungicidal composition.

[0174] The method typically involves applying 0.5 to 3 liters per hectare of the rosin-based composition disclosed herein and 0.5 to 2 liters per hectare of the fungicidal composition.

[0175] In some embodiments, the application rate of the fungicidal composition is 0.5 to 2 liters per hectare, preferably 0.5 to 1 liter per hectare, and even more preferably 0.5 to 0.75 liters per hectare.

[0176] In some preferred embodiments, the application rate of the fungicidal composition is 0.5 liters per hectare.

[0177] In some embodiments, the fungicidal composition is a copper-based composition, and the application rate is 0.5 to 2 liters per hectare, which is equivalent to a copper dose of 200 to 800 grams per hectare.

[0178] Generally, the composition according to the present invention is applied by spraying onto the plants.

[0179] In some preferred embodiments, the plant is a crop.

[0180] The spraying can be repeated several times on the plants.

[0181] In some embodiments, the spraying can be repeated at least twice, preferably 2 to 10 times.

[0182] In some embodiments, the spraying can be repeated at least twice, at intervals of 4 to 30 days, preferably at intervals of 7 to 20 days.

[0183] Non-limiting examples of the plant include grapevines, vegetables such as tomato plants, potato plants, lettuce, cucurbitaceous plants such as melons, and cereals such as wheat.

[0184] Preferably, the plant is a grapevine.

[0185] The following examples are presented to provide a complete disclosure and description to those of ordinary skill in the art on how to make and use the present invention, and are not intended to limit the scope of what the inventors regard as their invention, nor are they intended to represent that the following experiments are all or the only experiments conducted.

[0186] Bibliography

[0187] (1) Savluchinske-Feio et al., Applied Microbioly and Biotechnoly, 2006, 72, 430 - 436, “Antimicrobial activity of resin acid derivatives”.

[0188] (2) Gabaston, J. et al., Industrial Crops and Products, 2017, 103, 267 - 273, “Stilbenes from common spruce (Picea abies) bark as natural antifungal agent against downy mildew (Plasmopara viticola)”.

[0189] (3) Gabaston, J. et al., International Viticulture and Enology Society, 2022, 56, 55 - 68, “A grapevine by - product extract enriched in oligomerised stilbenes to control downy mildews: focus on its modes of action towards Plasmopara viticola”.

[0190] Examples

[0191] Materials and methods

[0192] Wood rosin was obtained from commercial products and MC, two resins from pine stumps, produced by Pinova, registered according to the Reach regulation, with the same CAS number as wood rosin, i.e., CAS 8050 - 09 - 7.

[0193] Example 1: Preparation of the composition according to the invention

[0194] First, dimethyl sulfoxide was mixed with the wetting agent described above. Then the resulting mixture was stirred and heated at 50 °C.

[0195] Wood rosin flakes were gradually added to the above - mentioned mixture under strong stirring.

[0196] The crude mixture was stirred until the wood rosin was completely dissolved. Then the stirring speed was slowed down and ethoxylated castor oil and tall oil fatty acids were added.

[0197] Finally, the mixture was stirred for another 20 minutes to obtain a homogeneous mixture.

[0198] According to this process, an emulsifiable concentrate C1 can be obtained from MC or an emulsifiable concentrate C2 can be obtained from obtained.

[0199] Example 2: Evaluation of the gene defense induction activity of composition C1 prepared according to Example 1 in grapevines

[0200] The ability to induce plant defense genes in a grapevine model was evaluated using the qPFD platform method with 15 marker genes (INRA patent WO2011 / 161388); grape variety: Cabernet Sauvignon.

[0201] These 15 marker genes were selected from pathogenesis-related proteins, phenylpropanoids, and oxidative stress.

[0202] RNA was extracted from leaf tissues treated with 6 different compositions. The yield and quality of the extracted RNA were evaluated using a spectrophotometer. Gene expression levels were calculated and normalized.

[0203] The results are shown in Table 1.

[0204] In this table, the following six compositions were evaluated and compared with an inducer control at day 0 (D0) and two days after treatment (D2). The six compositions are as follows:

[0205] - Emulsifiable concentrate from MC, pine stump extract: composition C1

[0206] - Emulsifiable concentrate from pine stump extract: composition C2

[0207] - Emulsifiable concentrate from turpentine extract: composition PK1

[0208] - Lignan fraction: F1

[0209] - Mixture of stilbenes and flavonoids: F2

[0210] - Resin acid fraction: F3

[0211] Fractions F1 to F3 were obtained by purifying the crude resin extract by silica gel chromatography.

[0212]

[0213] Table 1: Heatmap of the relative quantitative expression of 15 defense genes in grapevines. Six different candidate products were evaluated two days after treatment and compared with an inducer control.

[0214] H 2 O 2The application was carried out 24 hours (one day) after treatment to simulate pathogen invasion. Average relative gene expression was obtained by RT-qPXR in two independent biological replicates and relative to a water control.

[0215] qPFD analysis demonstrated that wood rosin and, more precisely, resin acids induced defense genes in grapevines against biotic stress.

[0216] Trials conducted over two years in vineyards showed that rosin composed of resin acids and formulated as an emulsifiable concentrate and MC had an effect against downy mildew. Higher defense gene expression was observed when using wood rosin from pine stump extracts compared to turpentine extracts.

[0217] F3 containing only resin acids provided the best results, confirming its activity as an inducer of defense genes against biotic stress.

[0218] This efficacy is due to the resin acids in rosin that can induce genes for grapevine defense. The stimulated plants can establish a defense system against fungal pathogens.

[0219] Example 3: Evaluation of the efficacy of the composition according to the invention against grapevine downy mildew

[0220] To evaluate the efficacy of the composition according to the invention against grapevine downy mildew (Plasmopara viticola), 30 field trials were conducted in France, Italy, Spain, and Greece from 2018 to 2020. The product was tested on several representative grapevine varieties under different agro-climatic conditions in European grape-growing regions. All trials were GEP (Good Experimental Practice) trials and were conducted according to EPPO PP 1 / 031 and French CEB M007 guidelines.

[0221] The composition prepared according to Example 1 was tested at 1 L / 10000 m 2 LWA (leaf wall area) and compared with a standard elicitor (25 g / ha of COS-OGA). C1 at 1 L / 10000 m 2 LWA was combined with a copper-based fungicide at 200 g / ha and compared with a copper-based fungicide at 750 g / ha to reduce the amount of copper required for downy mildew control. The copper-based fungicide composition was a commercial solution of copper hydroxide sold under the brand Action Pin.

[0222] Apply 8 to 10 times at intervals of 7 to 10 days, from the BBCH 13 (third leaf unfolded) to the BBCH 81 (beginning of maturity) crop stage, thus from April to early August. The spraying volume ranges from 150 to 1000 liters per hectare, depending on the amount of vegetation and local practices.

[0223] The experiment was designed as a randomized complete block design with 4 replications. The experimental plot size was 4 to 12 grapevine saplings (12.0 - 36.0m 2 ). To ensure a sufficient disease level, artificial inoculation was carried out by spraying a spore suspension on the grapevine saplings.

[0224] During the experiment, 2 to 3 disease symptoms related to the development of downy mildew and disease pressure were observed. 100 leaf or 100 grape cluster samples were observed per plot. The disease severity on the leaves or grape clusters was recorded on each observation day. The efficacy was calculated using the Abbott formula.

[0225] Statistical analysis included ANOVA variance analysis at a 5% α risk and the Newman - Keuls test for mean comparison.

[0226] The ANOVA statistical groups are represented by the letters "a", "b", and "c" in the following table.

[0227] Data with the same letter are statistically the same. Data with different letters are statistically different.

[0228] Example 3a: Evaluation of the application of a composition containing only wood rosin according to the invention on grapevine leaves and grape clusters Evaluation

[0229]

[0230] Table 2: Application results of the composition containing wood rosin on diseased leaves.

[0231]

[0232] Table 3: Application results of composition C1 on diseased grape clusters.

[0233] The wood rosin - based composition C1 showed a similar efficacy in protecting leaves and grape clusters to the COS - OGA standard elicitor. Happily, this concentration does not cause any phytotoxic effects.

[0234] Example 3b: Evaluation of the application by spraying on grapevine leaves and grape clusters of a composition containing wood rosin according to the invention in combination with a copper-based composition Evaluation

[0235] The following table summarizes the comparison of the combination of composition C1 with a copper - based composition at a reduced rate and a full - rate copper - based composition.

[0236]

[0237] Table 4: Application results of the combination of composition C1 and a copper-based composition at a reduced rate on diseased leaves.

[0238]

[0239] Table 5: Application results of the combination of composition C1 and a copper-based composition at a reduced rate on diseased grape clusters.

[0240] Spraying the combination of composition C1 and a copper-based composition at a reduced rate is as effective as spraying the full-rate copper-based composition in protecting grapevine leaves and grape clusters.

[0241] Furthermore, this concentration does not cause any phytotoxic effects.

[0242] Therefore, the wood rosin-based composition can reduce the use of copper while maintaining a certain degree of efficacy in preventing downy mildew.

Claims

1. Use of resin acids as inducers of defense genes against biotic stress in plants.

2. Use of resin acids according to claim 1, wherein the resin acids are derived from or contained in rosin.

3. Use of resin acids according to claim 2, wherein the rosin is selected from gum rosin, tall oil rosin, their derivatives or mixtures thereof, preferably the rosin is selected from gum rosin, tall oil rosin, their derivatives.

4. Use of resin acids according to any one of claims 1 to 3 as a phytosanitary product.

5. Use of resin acids according to any one of claims 2 to 4, wherein the rosin is derived from conifers, preferably from pine trees.

6. Use of resin acids according to any one of claims 3 to 5, wherein the gum rosin is extracted from pine stumps or the rosin is disproportionated tall oil rosin or dimerized tall oil rosin.

7. A composition comprising rosin according to any one of claims 2 to 6 and a solvent.

8. The composition according to claim 7, wherein the rosin contains 15 to 95% by weight of resin acids, in particular 20 to 85% by weight, in particular 40 to 80% by weight, in particular 60 to 80% by weight, or 40 to 75% by weight, more preferably 65 to 75% by weight, based on the total weight of the rosin.

9. The composition according to any one of claims 7 to 8, further comprising an emulsifier, a penetrant and a wetting agent. Preferably, the emulsifier is selected from the group consisting of ethoxylated castor oil, ethoxylated fatty alcohols, alkyl polyglycosides, ethoxylated rapeseed oil, glycerol polyether-2-cocoate, polyethoxylated polyol esters such as Levenol Polyoxyethylene sorbitan monolaurate is also known as polysorbate or Tween 20; preferably, the penetrant is selected from the group consisting of tall oil fatty acids, unsaturated fatty acids such as oleic acid or linoleic acid, and saturated fatty acids such as palmitic acid and stearic acid; preferably, the wetting agent is a terpene alcohol, in particular the wetting agent is selected from the group consisting of 2,6-dimethyloct-7-en-2-ol, α-terpineol, 4(8)-p-menthene-1-ol, cis-3,7-dimethyl-2,6-octadien-8-ol, trans-3,7-dimethyl-2,6-octadien-1-ol, 10-hydroxymethylene-2-pinene, 3,7-dimethyloct-6-en-1-ol.

10. The composition according to any one of claims 7 to 9, wherein the composition contains 15 to 25% by weight of rosin based on the total weight of the composition.

11. Use of the composition according to any one of claims 7 to 10 as an inducer of defense genes against biotic stress in plants.

12. A plant protection composition comprising the composition according to any one of claims 7 to 10 and a fungicide.

13. The plant protection composition according to claim 12, wherein the fungicide is selected from the group consisting of copper-based products such as copper hydroxide, Bordeaux mixture, dithiocarbamates, dicarboximides, potassium phosphonate, dipotassium phosphonate, monopotassium phosphite, disodium phosphonate, carboxamide, cyanoimidazole, acetamide, phenylamide and benzamide, phthalimide, cyanoacetamide oxime, amidosulfotriazole, triazolopyrimidineamine and piperidinyltriazoleisoxazoline.

14. A method for treating or preventing diseases in plants caused by at least one fungus and / or oomycete, the method comprising step (i): applying to the plant the composition according to any one of claims 7 to 10.

15. The method according to claim 14, comprising step (ii): applying a fungicidal composition to the plant, preferably the fungicidal composition contains copper.

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