Plant activator

Abstract

Provided is a plant activator with which it is possible to safely, stably, and effectively promote an increase in fruiting by appropriately spraying the activator onto plants or using the same for irrigation. The plant activator contains: at least one compound selected from an oxo fatty acid or a derivative thereof or a salt thereof; and a terpene.

Description

Plant activators

[0001] The present invention relates to a plant activator.

[0002] Technologies for regulating plant growth have been developed with the aim of improving the supply efficiency of grain plants and horticultural plants. In addition to measures such as optimizing temperature and sunlight conditions and fertilization, methods for activating plants using plant activators that have plant growth regulating effects such as promoting growth, suppressing dormancy, and alleviating stress have been reported.

[0003] Patent Document 1 discloses a method for efficiently producing ketooctadecadienoic acid, which is known as a functional component that exhibits a fat-burning effect, by using an enzyme. It also describes that the resulting ketooctadecadienoic acid can be used as a plant activator that exhibits a strong resistance-inducing effect.

[0004] Patent Document 2 discloses a method for early prediction of soybean yield by obtaining analytical data of one or more components selected from 2-hydroxypyridine, choline, citric acid, glyceric acid, glycine, L-pyroglutamic acid, malonic acid, sucrose, and threitol, which are metabolites contained in the leaves of a soybean sample to be predicted, and comparing the data with a yield prediction model.

[0005] Patent Document 3 describes a plant activator characterized by containing an oxo fatty acid derivative or its salt or ester as an active ingredient, which has low soil contamination and toxicity and excellent resistance induction effects. Patent Document 4 proposes a plant activator comprising one or more substances selected from (1) fatty acids or derivatives thereof, (2) organic acids or derivatives thereof, (3) lipids or derivatives thereof, (4) alcohols or derivatives thereof, (5) amines or derivatives thereof, (6) amino acids or derivatives thereof, (7) proteins or derivatives thereof, (8) nucleic acids or derivatives thereof, (9) terpenes or derivatives thereof, (A) natural product extracts, (B) fermentation products, (C) fermentation residues, and (I) vitamins. Examples of terpenes or derivatives thereof include orange oil, turpentine oil, peppermint oil, eucalyptus oil, camphor (d-camphor), dl-camphor, 1-menthol, dl-menthol, and thymol.

[0006] Japanese Patent Publication No. 2020-25534 Japanese Patent Publication No. 2020-174553 International Publication No. 2018 / 168860 Japanese Patent Publication No. 2001-288011

[0007] Grains, which are rich in starch and protein, are used as staple food or regular food for humans and animals, and increasing their yield is therefore extremely important. There is a need for a plant activator for increasing yield that can provide a growth-promoting effect superior to that of the plant activator containing ketooctadecadienoic acid as an active ingredient described in Patent Document 1 and the plant activator described in Patent Document 3, and that can stably and safely increase the grain yield.

[0008] Patent Document 2 describes that predicting soybean yield can significantly improve the efficiency of developing yield-increasing technologies, but does not disclose any specific yield-increasing technologies. Furthermore, the plant activator in Patent Document 4 is insufficient as a yield-increasing technology.

[0009] The present invention has been made in view of the above-mentioned problems, and aims to provide a plant activator that can be appropriately sprayed or irrigated onto plants to safely, stably, and effectively increase seed production.

[0010] The present invention relates to a plant activator comprising at least one compound selected from oxo fatty acids, derivatives thereof, or salts thereof, and a terpene. The oxo fatty acids in the present invention are fatty acids having a carbonyl group on a carbon skeleton other than a carboxyl group, and preferably do not have an α-ketol structure.

[0011] The oxo fatty acid is preferably an oxo fatty acid represented by the following formula (I) or the following formula (II): HOOC-(R 1 )-C β H=C α H-C(=O)-R 2 (I) In formula (I), R 1 R represents a linear or branched, saturated or unsaturated hydrocarbon group containing 6 to 12 carbon atoms. 2represents an alkyl group having 2 to 8 carbon atoms, which may contain one or more branches and / or double bonds. α is R １ The α-carbon is the first adjacent carbon from the carbonyl group on the side of C β is R １ The β-carbon atom is the second adjacent carbon atom from the carbonyl group. 3 )-C(=O)-C α H=C β H-R 4 (II) In formula (II), R 3 represents a linear or branched, saturated or unsaturated hydrocarbon group containing 3 to 10 carbon atoms. 4 represents a hydrocarbon group having 4 to 11 carbon atoms, which may contain one or more branches and / or double bonds. α is R ４ The α-carbon is the first adjacent carbon from the carbonyl group on the side of C β is R ４ It is the second adjacent beta carbon from the carbonyl group.

[0012] In the formula (I), R 1 is the α carbon C in the formula (I). α and β carbon C β and in the formula (II), R 4 is the α carbon C in the formula (II). α and β carbon C β It is preferable that the double bond between the double bond and the double bond between ... between the double bond between the double bond between the double bond between the double bond between the double bond between the double bond between the double bond between the double bond between the double bond between the double bond between the double bond

[0013] The oxo fatty acid represented by the formula (I) and the oxo fatty acid represented by the formula (II) are preferably ketooctadecadienoic acid.

[0014] In the formula (I), R 1 is a linear or branched hydrocarbon group having 9 carbon atoms, and R 2 is an alkyl group having 5 carbon atoms, and in the formula (II), R 3 is a linear or branched hydrocarbon group having 7 carbon atoms, and R 4It is preferred that the alkyl group has 7 carbon atoms and has the structure CH3-CH2-CH2-CH2-CH2-CH=CH-.

[0015] The oxo fatty acid is preferably at least one selected from the group consisting of 9-oxo-10,12-octadecadienoic acid, 13-oxo-9,11-octadecadienoic acid, 5-oxo-6,8-octadecadienoic acid, 6-oxo-9,12-octadecadienoic acid, 8-oxo-9,12-octadecadienoic acid, 10-oxo-8,12-octadecadienoic acid, 11-oxo-9,12-octadecadienoic acid, 12-oxo-9,13-octadecadienoic acid, and 14-oxo-9,12-octadecadienoic acid.

[0016] The plant activator preferably contains at least two or more kinds of oxo fatty acids.

[0017] The plant activator preferably contains at least one oxo fatty acid represented by formula (I) and at least one oxo fatty acid represented by formula (II).

[0018] In the plant activator, it is preferable that the oxo fatty acid represented by formula (I) is 13-oxo-9,11-octadecadienoic acid, and the oxo fatty acid represented by formula (II) is 9-oxo-10,12-octadecadienoic acid.

[0019] In the plant activator, the ratio of the content of 9-oxo-10,12-octadecadienoic acid to the content of 13-oxo-9,11-octadecadienoic acid is preferably 0.3 to 2.0 by weight. Furthermore, it is particularly desirable that the ratio of the content of 9-oxo-10,12-octadecadienoic acid to the content of 13-oxo-9,11-octadecadienoic acid is 1.0 to 2.0 by weight. This weight ratio (9-oxo-10,12-octadecadienoic acid / 13-oxo-9,11-octadecadienoic acid = 1.0 to 2.0) is particularly advantageous for flower bud formation in soybeans.

[0020] The plant activator is preferably a plant activator that increases the amount of production of at least one selected from the group consisting of 2-hydroxypyridine, glycine, L-pyroglutamic acid, and sucrose.

[0021] The plant activator is preferably a plant activator that increases the amount of plant hormone produced.

[0022] In the plant activator, the plant hormone is preferably gibberellin.

[0023] The plant activator is preferably one for promoting flower bud formation and / or improving yield.

[0024] In the plant activator, the terpene is preferably a monoterpene, and α-pinene is most preferred.

[0025] The plant activator is preferably a plant activator used as a spray or dipping agent to be brought into contact with the stems, leaves or roots of plants, or as a soil drench agent.

[0026] The plant activator is preferably a grass plant activator or a legume plant activator.

[0027] The plant activator preferably further contains a hydroxylated fatty acid, a derivative thereof, or a salt thereof.

[0028] The hydroxylated fatty acid is preferably at least one selected from the group consisting of 9,10,13-trihydroxy-11-octadecenoic acid and 9,12,13-trihydroxy-10-octadecenoic acid.

[0029] "9,10,13-trihydroxy-11-octadecenoic acid" is represented by the following structural formula (1).

[0030]

[0031] "9,12,13-trihydroxy-10-octadecenoic acid" is represented by the following structural formula (2).

[0032]

[0033] The plant activator of the present invention has a high effect of promoting flower bud formation and an excellent effect of increasing yield.

[0034] FIG. 1 is a diagram showing the analytical results of glycine in soybean leaves. FIG. 2 is a diagram showing the analytical results of sucrose in soybean leaves. FIG. 3 is a diagram showing the analytical results of 2-hydroxypyridine in soybean leaves. FIG. 4 is a diagram showing the analytical results of L-pyroglutamic acid in soybean leaves. FIG. 5 is a diagram showing the analytical results of gibberellin in soybean leaves. FIG. 6 is a diagram showing the analytical results of gibberellin in rice. FIG. 7 is a diagram showing the analytical results of gibberellin in soybean leaves in Comparative Example 5. FIG. 8 is a diagram showing the analytical results of glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid in soybean leaves in Comparative Example 5.

[0035] Plant Activator The plant activator of the present invention is characterized by containing at least one compound selected from oxo fatty acids or derivatives thereof or salts thereof, and a terpene.

[0036] In the present invention, "plant activation" means adjusting the growth activity of a plant in some way to activate or maintain it, and is a concept that includes plant growth regulating actions such as growth promotion (a concept that includes the expansion of stems and leaves, and the promotion of tuber and root growth, etc.), dormancy suppression, induction and imparting of plant resistance to stress (such as disease), and anti-aging.

[0037] As shown in the examples below, application of the plant activator of the present invention to a plant increases the contents of multiple components known to be correlated with increased grain yield and to serve as indicators of increased yield, and also increases plant hormones that promote flower bud formation, ovary growth, etc. Therefore, in the present invention, the "plant activating" effect can particularly mean the effect of promoting plant growth and increasing the grain weight and number per plant, thereby increasing grain yield. The plant activating effect of the plant activator of the present invention is very high, and as a result, it can bring about an excellent yield-increasing effect and improved harvesting efficiency in the plant to which it is applied.

[0038] The plant activator of the present invention contains, as active ingredients for activating plants, at least one compound selected from oxo fatty acids, derivatives thereof, or salts thereof, and a terpene.

[0039] More specifically, the plant activator of the present invention is characterized by containing at least one compound selected from oxo fatty acids represented by the following formula (I) or (II) or derivatives thereof or salts thereof, and a terpene: HOOC-(R 1 )-C β H=C α H-C(=O)-R 2 (I) In formula (I), R 1 R represents a linear or branched, saturated or unsaturated hydrocarbon group containing 6 to 12 carbon atoms. 2 represents an alkyl group having 2 to 8 carbon atoms, which may contain one or more branches and / or double bonds. α is R １ The α-carbon is the first adjacent carbon from the carbonyl group on the side of C β is R １ The β-carbon atom is the second adjacent carbon atom from the carbonyl group. 3 )-C(=O)-C α H=C β H-R 4 (II) In formula (II), R 3 represents a linear or branched, saturated or unsaturated hydrocarbon group containing 3 to 10 carbon atoms. 4 represents a hydrocarbon group having 4 to 11 carbon atoms, which may contain one or more branches and / or double bonds. α is R ４ The α-carbon is the first adjacent carbon from the carbonyl group on the side of C β is R ４ It is the second adjacent beta carbon from the carbonyl group.

[0040] The oxo fatty acids and compounds represented by formula (I) or (II) above include all geometric isomers and stereoisomers thereof having the same structural formula. As used herein, the term "stereoisomer" may refer to any of the various stereoisomeric configurations that may exist in the compounds of the present disclosure. For example, the compounds of formula (I) or (II) of the present disclosure contain double bonds, where the substituents may be in the E or Z configuration.

[0041] Preferably, the oxo fatty acid contained in the plant activator of the present invention is, for example, R 1 is the α carbon C in formula (I) α and β carbon C β In addition, the double bond between R and R in the above formula (II) may form a conjugated double bond. 4 is the α carbon C in formula (II) α and β carbon C β and a double bond between them that forms a conjugated double bond.

[0042] For example, ketooctadecadienoic acid is a suitable example of an oxo fatty acid. 1 may be a linear or branched hydrocarbon group having 9 carbon atoms, and R 2 may be an alkyl group having 5 carbon atoms. 3 may be a linear or branched hydrocarbon group having 7 carbon atoms, and R 4 When the number of carbon atoms is 7, it preferably has the structure CH3-CH2-CH2-CH2-CH2-CH=CH-.

[0043] For example, specific examples of ketooctadecadienoic acids include 9-oxo-10,12-octadecadienoic acid (9-oxoODA), 13-oxo-9,11-octadecadienoic acid (13-oxoODA), 5-oxo-6,8-octadecadienoic acid, 6-oxo-9,12-octadecadienoic acid, 8-oxo-9,12-octadecadienoic acid, 10-oxo-8,12-octadecadienoic acid, 11-oxo-9,12-octadecadienoic acid, 12-oxo-9,13-octadecadienoic acid, and 14-oxo-9,12-octadecadienoic acid. As used herein, "active ingredient" refers to oxo fatty acids and terpenes, including the specific examples listed. Oxo fatty acids have the property of activating plant growth, and by contacting a part of a plant's stems, leaves, or roots with the plant activator of the present invention, which contains an oxo fatty acid, or a derivative or a salt thereof, and a terpene as active ingredients, the plant's seed yield can be improved. Preferably, the plant activator of the present invention contains at least two or more oxo fatty acids, or derivatives or salts thereof, as one of the active ingredients, the oxo fatty acid, or a derivative or salt thereof.

[0044] The oxo fatty acid derivative is preferably an ester, and examples of the oxo fatty acid ester of the present invention include, but are not limited to, methyl ester, ethyl ester, propyl ester, butyl ester, pentyl ester, isopentyl ester, and octyl ester.

[0045] The salt of the oxo fatty acid is not particularly limited as long as it is one or more agriculturally acceptable salts, for example, alkali metal salts such as sodium salts and potassium salts, ammonium salts such as ammonium salts and alkylammonium salts such as tetramethylammonium salts, etc.

[0046] The plant activator of the present invention may contain at least two or more oxo fatty acids as active ingredients. By combining two or more oxo fatty acids, the plant activator of the present invention may exhibit even greater plant activation effects. For example, the two oxo fatty acids may be a combination of at least one oxo fatty acid represented by formula (I) above and at least one oxo fatty acid represented by formula (II) above. For example, the two oxo fatty acids may preferably be a combination of 9-oxo-10,12-octadecadienoic acid (9-oxoODA) and 13-oxo-9,11-octadecadienoic acid (13-oxoODA).

[0047] In one embodiment of the present invention, the plant activator contains, as oxo fatty acids, 13-oxo-9,11-octadecadienoic acid or a salt or derivative thereof and 9-oxo-10,12-octadecadienoic acid or a salt or derivative thereof. For example, the ratio of the content of 9-oxo-10,12-octadecadienoic acid or a salt or derivative thereof to the content of 13-oxo-9,11-octadecadienoic acid or a salt or derivative thereof is about 0.1 to 10, preferably about 0.3 to 2.0, by weight.

[0048] The terpene contained in the plant activator of the present invention is a precursor in the biosynthesis of plant hormones related to increased grain yield. Therefore, by containing a terpene as an active ingredient in addition to at least one compound selected from oxo fatty acids, derivatives thereof, or salts thereof, the plant activator of the present invention can further increase the biosynthesis of plant hormones in addition to the plant growth-promoting effect of the at least one compound selected from oxo fatty acids, derivatives thereof, or salts thereof.

[0049] Any terpene may be suitably used, but monoterpenes, sesquiterpenes, diterpenes, and their derivatives are preferred. Particularly preferred examples include monoterpenes such as α-pinene, β-pinene, silvestrene, and limonene, which are core plant hormones. Terpineol may also be included. Terpineol includes its isomers α-terpineol, β-terpineol, and γ-terpineol, with α-terpineol being more preferred. For example, commercially available terpineol may be a mixture of β-terpineol and γ-terpineol, with α-terpineol being the primary component. As long as it primarily contains α-terpineol, the mixture of isomers can be used as is. Pine oil containing α-pinene as the primary component may be suitably used in the present invention.

[0050] The addition of the terpene of the present invention does not reduce or eliminate the excellent growth-promoting effect of the plant activator containing the oxo fatty acid, or a derivative thereof, or a salt thereof. Furthermore, terpenes are naturally occurring compounds, have a low environmental impact, and the addition of terpenes does not adversely affect the plants to which they are applied. Therefore, the addition of the terpene of the present invention further promotes plant hormone biosynthesis while maintaining the excellent activating effect of the plant activator containing the oxo fatty acid, or a derivative thereof, or a salt thereof, thereby achieving a significant yield-increasing effect of the plant activator of the present invention.

[0051] In the present invention, the terpene may be contained in the plant activator in a weight ratio of about 10 times or less the amount of the oxo fatty acid, or a derivative thereof, or a salt thereof. The preferred concentration of the terpene contained in the plant activator of the present invention depends on the plant species and its condition to which it is applied, and there is no particular lower limit for the terpene concentration, but it is preferably contained in an amount of about 0.5 times or more the amount of the oxo fatty acid, or a derivative thereof, or a salt thereof. In a preferred embodiment of the present invention, the terpene may be contained in an amount of about 1 to 3 times the amount of the oxo fatty acid, or a derivative thereof, or a salt thereof.

[0052] For example, in one embodiment of the plant activator of the present invention, at least one compound selected from oxo fatty acids, derivatives thereof, or salts thereof can be used at a concentration of 5 mg / L or less. The preferred concentration of at least one compound selected from oxo fatty acids, derivatives thereof, or salts thereof depends on the cultivation conditions and growth stage of the plant to which the plant activator is applied, the application timing and application method, etc., and can be appropriately set to suit the application amount. However, concentrations exceeding 5 mg / L may cause phytotoxicity to the plant. The lower limit of the concentration of at least one compound selected from oxo fatty acids, derivatives thereof, or salts thereof is not particularly limited, but 0.05 mg / L or more is preferred. In a preferred embodiment of the present invention, the concentration of at least one compound selected from oxo fatty acids, derivatives thereof, or salts thereof is 0.05 to 5 mg / L.

[0053] The plant activator of the present invention may optionally contain additional components such as a compatible surfactant and / or diluent or carrier suitable for use as a plant activator. For example, the diluent may improve the dispersibility of at least one compound selected from oxo fatty acids, their derivatives, or salts thereof in a solvent. Furthermore, surfactants such as dispersing aids and wetting agents may be included to improve the solubility or dispersibility of the oxo fatty acid derivatives used in the present invention in the diluent. These additional components are not particularly limited as long as they are agriculturally acceptable. Furthermore, the plant activator of the present invention may further contain, in addition to the surfactant, diluent, and carrier, other components commonly used in pesticide formulations, such as pH adjusters, wetting agents for increasing the spreading ability of the formulation in plants or soil, binders, antioxidants, and other components beneficial to plants, such as one or more fertilizer components, in addition to the at least one compound selected from oxo fatty acids, their derivatives, or salts thereof, and terpenes.

[0054] The plant activator of the present invention may contain, in addition to a terpene, at least one compound selected from oxo fatty acids, derivatives thereof, or salts thereof, with no particular limitation on their origin. The oxo fatty acids, such as ketooctadecadienoic acid, or derivatives thereof or salts thereof of the present invention may be obtained, for example, by chemical synthesis, or may be produced using a microorganism or obtained by the action of a microbial enzyme on a substrate such as a fatty acid. The plant activator of the present invention may contain at least one compound selected from oxo fatty acids, derivatives thereof, or salts thereof at a desired concentration. For example, when an oxo fatty acid derivative produced using a microorganism is used as the oxo fatty acid derivative, a mixture containing the oxo fatty acid may be used as the plant activator. When a biosurfactant secreted by a microorganism is contained in the mixture, the dispersibility of the plant activator of the present invention may be improved without the addition of the aforementioned additive components. Even when oxo fatty acids or derivatives thereof themselves are insoluble, they may be emulsified with a biosurfactant and dispersed in water.

[0055] In one embodiment of the present invention, the plant activator of the present invention may further contain, as active ingredients, a hydroxylated fatty acid or a derivative or a salt thereof in addition to at least one compound selected from an oxo fatty acid, a derivative thereof, or a salt thereof and a terpene, thereby obtaining a plant activator with even higher activation effects.

[0056] As the hydroxylated fatty acid, its derivative or its salt, a hydroxylated fatty acid having the structural formula (III) and / or (IV) below, or a derivative or a salt thereof, can be suitably used. HOOC-(R 5 )-CH(OH)-CH(OH)-CH=CH-CH(OH)-R 6 (III) HOOC-(R 5 )-CH(OH)-CH=CH-CH(OH)-CH(OH)-R 6 (IV) In formula (III) and / or (IV), R 5R is a linear or branched hydrocarbon group having 4 to 12 carbon atoms, which may contain one or more double bonds and / or OH groups, and when it contains a double bond, the position of the double bond is not limited. 6 is a linear or branched hydrocarbon group having 2 to 8 carbon atoms, which may contain one or more double bonds and / or OH groups, and when it contains a double bond, the position of the double bond is not limited.

[0057] The hydroxylated fatty acid derivatives and salts thereof may be those exemplified above as oxo fatty acid derivatives and salts thereof. The hydroxylated fatty acids of the present disclosure include all geometric isomers and stereoisomers of the compounds represented by formula (III) and / or (IV).

[0058] In one embodiment of the present invention, R in formula (III) and / or (IV) above 5 The hydrocarbon group of R has 6 to 8 carbon atoms, 6 In another embodiment, the hydrocarbon group of R in the hydroxylated fatty acid has 4 to 6 carbon atoms. 5 is -(CH2) n -(n is an integer of 4 to 12), and R 6 is C n H 2n+1 -(n is an integer of 2 to 8). 5 is an alkylene group having 7 carbon atoms (-(CH2)7-), and R 6 is preferably an alkyl group having 5 carbon atoms (CH3CH2CH2CH2CH2-).

[0059] Preferably, the hydroxylated fatty acid of the present disclosure can be at least one selected from the group consisting of 9,10,13-trihydroxy-11-octadecenoic acid and 9,12,13-trihydroxy-10-octadecenoic acid, but is not limited thereto.

[0060] As described above, the plant activator of the present invention, which contains at least one compound selected from oxo fatty acids, derivatives thereof, or salts thereof, and a terpene, is characterized by exhibiting a significantly excellent plant activating effect, promoting the growth of plant seeds and increasing seed yield, when applied to plants. Compounds that are well correlated with increased seed yield, and whose increased content is an indicator of increased seed yield, include compounds such as 2-hydroxypyridine, glycine, L-pyroglutamic acid, and sucrose. It is believed that there is a positive correlation between the amounts of these components present in leaves and seed yield.

[0061] The plant activator of the present invention can increase the content of 2-hydroxypyridine, glycine, L-pyroglutamic acid, and / or sucrose in the leaves of a plant to which it is applied. These results indicate that the plant activator of the present invention can promote the growth of plant seeds and increase the weight and number of seeds per plant. In other words, the plant activator of the present invention is a yield-increasing agent. Note that "increased yield" of seeds means an increase in the number of harvested seeds, for example, an increase in the weight and / or number of seeds per plant compared to a group of plants not treated with the plant activator of the present invention.

[0062] The plant activator of the present invention can also increase the content of plant hormones in the leaves of plants to which it is applied, which are associated with increased seed yield. The plant activator of the present invention can, for example, increase the content of gibberellin in the leaves, a plant hormone that has the physiological effects of promoting flower bud formation and ovary growth. It is known that seed yield is positively correlated with the number of pods, and the number of pods is closely positively correlated with the number of flower buds. Therefore, an increase in the amount of gibberellin, which can promote inflorescence development, can result in an increase in the number of flower buds and pods, and ultimately in yield. In other words, the plant activator of the present invention can induce an increase in gibberellin biosynthesis, i.e., it is a flower bud formation promoter.

[0063] For example, the plant activator of the present invention can be suitably used to increase the yield of grains, but is not limited thereto. The grains are not particularly limited and can be appropriately selected depending on the purpose. For example, the plant activator of the present invention may be applied to grasses, legumes, etc., and can suitably achieve an increase in their grain yield. Specific examples of grasses include wheat, barley, rye, oats, and naked barley, as well as rice, sorghum, corn, foxtail millet, millet, barnyard millet, finger millet, pearl millet, and lawn grass. Specific examples of legumes include, but are not limited to, soybean, adzuki bean, mung bean, cowpea, kidney bean, lima bean, peanut, pea, and broad bean. The plant activator of the present invention can also be suitably used to increase the grain yield of plants other than the above-mentioned grasses and legumes.

[0064] Among the above-mentioned grasses and legumes, the plant activator of the present invention can be suitably used for rice (rice) and soybeans. The type of rice is not particularly limited and can be appropriately selected depending on the purpose, and examples include sake rice such as Hakutsuru Nishiki, Yamadanishiki, Gohyakumangoku, Miyamanishiki, Omachi, Hattan, Hattan Nishiki, Ginpu, Yumesansa, Wakamizu, and Yumenoka, and edible rice such as Nipponbare, Koshihikari, Hitomebore, Hinohikari, Akitakomachi, Kinuhikari, Nanatsuboshi, and Haenuki.

[0065] In this specification, soybean refers to soybean (scientific name: Glycine max), an annual plant of the legume family. There are a wide variety of soybean varieties, but the soybean plant activator of the present invention can be suitably used for domestic soybeans such as Fukuyutaka, Enrei, Sato no Hohoemi, Yuagari Musume, Ryuho, Suzuyutaka, Toyomare, and Miyagishirome, as well as U.S. soybeans such as IOM (Indiana, Ohio, Michigan). It also does not matter whether the soybeans are genetically modified or non-genetically modified.

[0066] The plant activator of the present invention can be applied to plants by any method. The application method is not particularly limited as long as it contacts the plant body, such as the roots, stems, or leaves, and it is suitable as an activator for promoting flower bud formation and / or improving yield in plant cultivation. The plant activator of the present invention may be applied so as to come into direct contact with the plant body, or to a cultivation support, such as soil or a medium, in which the plant body is established. For example, the plant activator of the present invention can be used as a spray or immersion agent that comes into contact with the stems, leaves, or roots of the plant, or as a soil drench agent. Specific application methods can be appropriately selected depending on the cultivation form of the plant to be applied, and include, for example, aboveground liquid application, aboveground solid application, aerial liquid application, aerial solid application, liquid surface application, indoor application, soil incorporation application, soil drench application, surface treatment such as paint application, seedling box application, single flower application, and base treatment. The plant activator of the present invention may also be mixed with plant fertilizer components and used as a plant fertilizer. The plant activator of the present invention may also be contained in a porous structure or capsule, or impregnated in a sheet or the like and used as a sustained-release agent. The form of the plant activator of the present invention is not particularly limited. The plant activator of the present invention may be in a liquid or gel form, or in a solid form (block, powder, granules, etc.). In the case of a liquid composition, it may be a concentrated type that can be used as is or after dilution. The plant activator of the present invention imparts a plant growth-promoting effect to plants during plant cultivation, and in the applied plant, increases the grain yield by increasing the plant body, such as increasing the crop weight, and improves the grain yield and harvest efficiency by promoting flower bud formation.

[0067] The plant activator of the present invention can improve grain yield by a simple treatment such as spraying, eliminating the need for special equipment, etc., making the present invention extremely advantageous in this respect as well. Furthermore, because oxo fatty acids and the like are oxides of naturally occurring fatty acids, and terpenes are also naturally occurring compounds as described above, the plant activator of the present invention has a low environmental impact and is almost free of phytotoxicity to plants to which it is applied, making the plant activator of the present invention also excellent.

[0068] The plant activator of the present invention can be applied to a plant and / or a cultivation support, for example, by a method in which at least one compound selected from oxo fatty acids, derivatives thereof, or salts thereof is applied to the plant and / or cultivation support in the form of a liquid dissolved or dispersed in water and / or a water-soluble solvent. For example, a liquid in which at least one compound selected from oxo fatty acids, derivatives thereof, or salts thereof is dissolved or dispersed can be sprayed or applied to the above-ground parts (stems, leaves, etc.) of the target plant. The plant activator of the present invention may be applied to the target plant at least once before flowering, for example, or may be applied in multiple installments.

[0069] The present invention will be described based on examples, but the present invention is not limited to only the examples.

[0070] Example 1 Preparation of Growth-Promoting Solution 1 580 g of 90% pure linoleic acid (NOF Corp.) was used as a fatty acid-containing raw material, and 216 g of potassium carbonate (FUJIFILM Wako Pure Chemical Industries, Ltd.), 280 g of dipotassium hydrogen phosphate (FUJIFILM Wako Pure Chemical Industries, Ltd.), and 13,000 mL of distilled water were added to prepare a test solution. The pH of the test solution at this time was 9.0.

[0071] To the test solution, 40 mg of lipoxygenase (Nacalai Tesque, Inc., soybean-derived) was added, and the mixture was reacted at 15°C for 3 hours while being aerated with oxygen and stirred. The reaction mixture was then placed in a water bath at 90°C for 90 minutes. The resulting reaction solution was designated as Solution A.

[0072] To 6500 mL of Solution A, 35 mL of phosphoric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to adjust the pH to 7.0. This solution was reacted at 50°C for 22 hours while being aerated with oxygen and stirred, and then the reaction mixture was placed in a water bath at 90°C for 2 hours. The resulting reaction solution was designated Solution B.

[0073] The entire amount of Solution B obtained above was mixed with the entire amount of Solution A remaining without using it for the preparation of Solution B. The resulting mixture was used as a standard substance, which was then mixed with 13-oxoODA (13-oxo-9,11-octadecadienoic acid), 9-oxoODA (9-oxo-10,12-octadecadienoic acid) manufactured by Cayman Chemical Company, and 9,10,13-trihydroxy-11-octadecenoic acid (9,10,13-trihydroxy-11-octadecenoic acid) manufactured by Larodan Fine Chemicals. 9,12,13-trihydroxy-10-octadecenoic acid and 9,12,13-trihydroxy-10-octadecenoic acid were used, and MS 2 The amounts were quantified by liquid chromatography-mass spectrometry (LC-MS) using spectral analysis. Ketooctadecadienoic acid (13-oxoODA, 9-oxoODA) was detected at a UV wavelength of 272 nm, and trihydroxyoctadecenoic acid was detected at a UV wavelength of 210 nm, using the absolute calibration curve method.

[0074] 13-oxoODA was obtained in a yield of 3.7%, which is the combined yield of isomers such as (E,E isomer) and (E,Z isomer). The yield of 9-oxoODA was 1.7%. The combined yield of 9,10,13-trihydroxy-11-octadecenoic acid and 9,12,13-trihydroxy-10-octadecenoic acid was 1.2% (peaks were inseparable by LC-MS), and the recovery of linoleic acid was 84.1%.

[0075] The yield (%) was calculated based on the following formula: Yield (%) = (wt % of 13-oxoODA, 9-oxoODA, 9,10,13-trihydroxy-11-octadecenoic acid, or 9,12,13-trihydroxy-10-octadecenoic acid produced) / (initial wt % of raw material linoleic acid used)

[0076] 0.1 mL of the mixture of solutions A and B obtained above was diluted with ion-exchanged water to 2000 mL, and 40 μL of pine oil (manufactured by Ease, Inc., main component: α-pinene) was added to this diluted solution to prepare growth promoter solution 1 (9-oxoODA / 13-oxoODA<1).

[0077] - Growth-promoting effect on rice Rice (variety: Nipponbare) seeds were immersed in water for 5 days in a climate control chamber (LH-60FL3-DT: manufactured by Nippon Medical and Chemical Machinery Co., Ltd.) at a temperature of 15°C with the lights off, and then the temperature was raised to 30°C for half a day. The resulting pigeon-breasted seeds (seeds that were uniformly swollen and had sprouted young shoots) were sown four per cell in a 72-well cell tray containing sterilized "Tanemaki soil" (manufactured by Takii Seed Co., Ltd.). The seeds were grown in the climate control chamber under fluorescent light at 28°C for 14 hours and then under light at 23°C for 10 hours, with the lights off, until they reached the 1- to 1.5-leaf stage.

[0078] The above-mentioned growth promoter solution 1 (9-oxoODA / 13-oxoODA<1) was sprayed onto the leaf surfaces of 20 rice plants at 1 mL per plant using a spray bottle 7 days after sowing.

[0079] 24 hours after spraying, the above-ground parts of each sample, consisting of two plants per sample, were cut off and weighed (fresh weight: FW) in a 15 mL centrifuge tube with a lid, and immediately transferred to a freezer at -80°C and frozen for 24 hours.

[0080] A mixture of ethanol, water, and acetic acid (80:20:1) was added to the frozen sample to give a concentration of 0.1 g / 1 mL, and the sample was crushed with beads and then ultrasonicated for 10 minutes. The sample was left to stand for 1 hour and centrifuged at 3,000 rpm for 5 minutes in a centrifuge (himac CT6E, manufactured by Eppendorf-Himac Technologies). The supernatant was filtered through a membrane filter to obtain the analytical sample.

[0081] The analytical sample was subjected to plant hormone analysis using a liquid chromatography mass spectrometry (LC-MS / MS) system (LC section: DIONEX Ultimate 3000, MS / MS section: Q Exactive Focus: manufactured by Thermo Fisher Scientific Co., Ltd.) under the following conditions: Column: Acclaim PR-MS 2.1 mmφ × 150 mm (manufactured by Thermo Fisher Scientific Co., Ltd.), Solvent: 2% acetonitrile / acetic acid water → 95% acetonitrile / acetic acid water, Flow rate: 0.25 mL / min, Column temperature: 40°C, Detection: MS-(SIM), Intake: 2 μL of sample solution.

[0082] A calibration curve was prepared using Gibberellin A1 (Toronto) as a gibberellin standard substance. Using the prepared calibration curve, the gibberellin content in the analytical sample was quantified from the MS- peak area value of the analytical sample. The gibberellin content in the rice sample 24 hours after spraying was 0.38 ng / gFW. The gibberellin quantification results are shown in Figure 6, plotted as a relative value relative to Comparative Example 1, described below, which is set to 1.0.

[0083] Example 2 - Growth promotion effect of soybeans Soybean seeds (variety: Fukuyutaka) were sown four seeds per pot in No. 3 pots containing "Vegetable and Flower Seed Soil" (manufactured by Takii Seed Co., Ltd.) The seeds were grown for 30 days in an artificial climate chamber (LH-60FL3-DT: manufactured by Nippon Medical and Chemical Instruments Manufacturing Co., Ltd.) with a daily cycle of 14 hours at 25°C under fluorescent light and 10 hours at 20°C with the lights off.

[0084] The growth promoter solution 1 (9-oxoODA / 13-oxoODA<1) prepared in Example 1 was sprayed onto the leaf surfaces of soybean plants 30 days after sowing using a spray bottle at 1 mL per plant to 20 plants.

[0085] 24 hours after spraying, five samples, each consisting of two plants, were cut from the growing point including the new leaves, weighed in a 15 mL centrifuge tube with a lid (fresh weight: FW), and immediately transferred to a -80°C freezer and frozen for 24 hours.

[0086] The frozen sample was treated in the same manner as in Example 1 to prepare an analytical sample.

[0087] The analytical sample was analyzed for glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid using an LC-MS / MS system under the following conditions: Column: Aclaim PR-MS 2.1 mmφ×150 mm (Thermo Fisher Scientific), Solvent: 2% acetonitrile / acetic acid in water → 10% acetonitrile / acetic acid in water, Flow rate: 0.25 mL / min, Column temperature: 40°C, Detection: MS-(SIM), Intake: 2 μL of sample solution. A calibration curve was prepared using glycine (FUJIFILM Wako Pure Chemical Industries, Ltd.), sucrose (FUJIFILM Wako Pure Chemical Industries, Ltd.), 2-hydroxypyridine (Tokyo Chemical Industry Co., Ltd.), and L-pyroglutamic acid (Nacalai Tesque, Inc.) as standard substances. Using the prepared calibration curve, the amounts of glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid in the analytical samples were quantified from the MS-peak area values. The results are shown in graphs as relative values, with the value for Comparative Example 3 (an example in which water was applied instead of a growth promoter solution), described below, set at 1.0. The quantitative results for glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid are shown in Figures 1 to 4, respectively.

[0088] The amount of gibberellin in the analytical samples was also quantified in the same manner as in Example 1. The gibberellin content in the soybean samples 24 hours after application was 4.0 ng / g FW. The results of the gibberellin quantification, shown as a graph relative to the value of Comparative Example 3 (an example in which water was applied instead of a growth-promoting solution) described below, are set at 1.0, and are shown in Figure 5.

[0089] Example 3 Preparation of Growth-Promoting Solution 2 580 g of 90% pure linoleic acid (NOF Corp.) was used as a fatty acid-containing raw material, and 216 g of potassium carbonate (FUJIFILM Wako Pure Chemical Industries, Ltd.), 280 g of dipotassium hydrogen phosphate (FUJIFILM Wako Pure Chemical Industries, Ltd.), and 13,000 mL of distilled water were added to prepare a test solution. The pH of the test solution at this time was 9.0.

[0090] 40 mg of lipoxygenase (Nacalai Tesque, Inc., soybean-derived) was added to the test solution, and the mixture was allowed to react at 15°C for 3 hours with stirring. The reaction mixture was then placed in a 90°C water bath for 90 minutes. 35 mL of phosphoric acid (Fujifilm Wako Pure Chemical Industries, Ltd.) was added to the mixture to adjust the pH to 7.0. The solution was reacted at 50°C for 22 hours with oxygen aeration and stirring, and the reaction mixture was then placed in a 90°C water bath for 2 hours.

[0091] The reaction solution obtained after the completion of the reaction was subjected to MS analysis using 13-oxoODA and 9-oxoODA manufactured by Cayman Chemical Company, and 9,10,13-trihydroxy-11-octadecenoic acid and 9,12,13-trihydroxy-10-octadecenoic acid manufactured by Larodan Fine Chemicals as standard substances. 2 Quantitation was performed by LC-MS using spectral analysis. Ketooctadecadienoic acid (13-oxoODA, 9-oxoODA) was detected at a UV wavelength of 272 nm, and trihydroxyoctadecenoic acid was detected at a UV wavelength of 210 nm, using the absolute calibration curve method.

[0092] The combined yield of 13-oxoODA, including isomers such as (E,E isomer) and (E,Z isomer), was 3.3%. The yield of 9-oxoODA was 6.5%. The combined yield of 9,10,13-trihydroxy-11-octadecenoic acid and 9,12,13-trihydroxy-10-octadecenoic acid was 0.63% (peaks were inseparable by LC-MS), and the recovery of linoleic acid was 80.2%.

[0093] 0.1 mL of the reaction solution obtained above was diluted to 2000 mL with ion-exchanged water, and 40 μL of pine oil (manufactured by Ease) was added to this diluted solution to prepare growth promoter solution 2 (9-oxoODA / 13-oxoODA>1).

[0094] Growth-promoting solution 2 was sprayed on rice plants in the same manner as in Example 1, and samples were collected and extracted, followed by component analysis of the resulting analytical samples. The gibberellin content in the rice samples 24 hours after spraying was 0.41 ng / gFW. The quantitative results of gibberellin are shown in a graph in Figure 6, where the value in Comparative Example 1, described below, is set to 1.0.

[0095] Example 4 Growth-promoting effect on soybeans Growth-promoting agent solution 2 (9-oxoODA / 13-oxoODA>1) prepared in the same manner as in Example 3 was sprayed on soybeans in the same manner as in Example 2, and samples were collected and extracted, and the components of the obtained analytical samples were analyzed.

[0096] The amounts of glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid in the soybean samples 24 hours after application were quantified in the same manner as in Example 2. The results are shown in graphs as relative values, with the value of Comparative Example 3 (an example in which water was applied instead of the growth-promoting solution) described below being set at 1.0. The quantification results for glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid are shown in Figures 1 to 4, respectively.

[0097] The gibberellin content in the soybean samples 24 hours after application was 5.2 ng / g FW. The quantitative results of gibberellin are shown in a graph in relative values, with the value for Comparative Example 3 (an example in which water was applied instead of a growth-promoting solution) described below being set at 1.0, as shown in Figure 5.

[0098] Comparative Example 1 A 0.1 mL mixture of solutions A and B (9-oxoODA / 13-oxoODA<1, no pine oil added) prepared in the same manner as in Example 1 was diluted with ion-exchanged water to 2000 mL to prepare comparative solution 1.

[0099] As in Example 1, Comparative Solution 1 was sprayed on rice plants, followed by sample recovery, extraction, and component analysis of the resulting analytical sample. The gibberellin content in the rice sample 24 hours after spraying was 0.15 ng / gFW. The analytical result of this analysis was set to 1.0, and the analytical results of Examples 1 and 3 and Test Example 1 described below were expressed as relative values. The results are shown in Figure 6.

[0100] Comparative Example 2 Comparative solution 1 prepared in the same manner as in Comparative Example 1 was sprayed on soybeans in the same manner as in Example 2, and samples were collected, extracted, and the components of the obtained analytical samples were analyzed.

[0101] The amounts of glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid in the soybean samples 24 hours after application were quantified in the same manner as in Example 2. The results are shown in graphs as relative values, with the value of Comparative Example 3 (an example in which water was applied instead of the growth-promoting solution) described below being set at 1.0. The quantification results for glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid are shown in Figures 1 to 4, respectively.

[0102] The gibberellin content in the soybean samples 24 hours after application was 3.2 ng / g FW. The quantitative results of gibberellin are shown in a graph in which the value for Comparative Example 3 (an example in which water was applied instead of a growth-promoting solution) described below is set to 1.0, and are shown in Figure 5.

[0103] Comparative Example 3 Ion-exchanged water was used instead of growth-promoting solution 1 in Example 2, and the ion-exchanged water was sprayed on the leaf surfaces of soybeans in the same manner as in Example 2. Thereafter, sample collection and extraction were carried out in the same manner as in Example 2, and the components of the obtained analytical samples were analyzed.

[0104] The analytical results of glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid in the soybean samples 24 hours after spraying were each set to 1.0, and the analytical results of Examples 2 and 4, Comparative Example 2, and Test Example 2 described below were expressed as relative values. The results are shown in Figures 1 to 4, respectively.

[0105] The gibberellin content in the soybean sample 24 hours after application was 3.1 ng / gFW. This analytical result was set to 1.0, and the analytical results of Examples 2 and 4, Comparative Example 2, and Test Example 2 described below are shown as relative values ​​in Figure 5.

[0106] Comparative Example 4 Pine oil (manufactured by Ease) was used instead of Growth Promoting Agent Solution 1 in Example 2, and the pine oil was sprayed on the leaves of soybeans in the same manner as in Example 2. Thereafter, sample collection and extraction were carried out in the same manner as in Example 2, and the components of the obtained analytical samples were analyzed.

[0107] The amounts of glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid in the soybean samples 24 hours after application were quantified in the same manner as in Example 2. The results are shown in graphs as relative values, with the value for Comparative Example 3 (an example in which water was applied instead of the growth promoter solution) set at 1.0. The quantification results for glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid are shown in Figures 1 to 4, respectively.

[0108] Comparative Example 5 Stearic acid was added to 2000 mL of ion-exchanged water to prepare a stearic acid dispersion adjusted to 50 ppm, to which 40 μL of pine oil (manufactured by Ease, Inc., main component: α-pinene) was added to prepare comparative solution 5. In the same manner as in Example 4, comparative solution 5 was sprayed on soybeans, and the contents of gibberellin, glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid in the soybean samples 24 hours after spraying were measured.

[0109] The gibberellin content in the soybean sample was 3.2 ng / gFW. The gibberellin quantification results, shown as a graph relative to the value of Comparative Example 3, which was set to 1.0, are shown in Figure 7. The amounts of glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid in the soybean sample 24 hours after spraying are also shown as a graph relative to the value of Comparative Example 3, which was set to 1.0. The quantification results are shown in Figure 8.

[0110] Test Example 1 A solution of 0.1 mL of a reaction solution (9-oxoODA / 13-oxoODA>1, no pine oil added) prepared in the same manner as in Example 3 was diluted with ion-exchanged water to 2000 mL, and used as test solution 1.

[0111] As in Example 3, Test Solution 1 was sprayed on rice plants, and samples were collected and extracted, followed by component analysis of the resulting analytical samples. The gibberellin content in the rice samples 24 hours after spraying was 0.23 ng / gFW. The quantitative results of gibberellin, plotted as a relative value relative to Comparative Example 1 (set to 1.0), are shown in Figure 6.

[0112] Test Example 2 Test solution 1 prepared in the same manner as in Test Example 1 was sprayed on soybeans in the same manner as in Example 4, and samples were collected and extracted, and the components of the obtained analytical samples were analyzed.

[0113] The amounts of glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid in the soybean samples 24 hours after application were quantified in the same manner as in Example 4. The results are shown in graphs as relative values, with the value of Comparative Example 3 (an example in which water was applied instead of the growth-promoting solution) described below being set at 1.0. The quantification results for glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid are shown in Figures 1 to 4, respectively.

[0114] The gibberellin content in the soybean samples 24 hours after application was 3.8 ng / g FW. The quantitative results of gibberellin are shown in a graph in which the value for Comparative Example 3 (an example in which water was applied instead of a growth-promoting solution) described below is set to 1.0, and are shown in Figure 5.

[0115] 1 to 4 , the contents of glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid were increased in soybean leaves to which the growth-promoting solutions containing oxo fatty acids and terpenes (Examples 2 and 4) were applied, compared with those to which the terpene-free solution (Comparative Example 2 and Test Example 2) and the terpene-only solution (Comparative Example 4) were applied, respectively. The results of Examples 2 and 4 show that the contents of glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid in soybean leaves were increased more when the growth-promoting solution of Example 4 containing a high amount of 9-oxoODA (9-oxoODA / 13-oxoODA>1) was applied than when the growth-promoting solution containing a high amount of 13-oxoODA (9-oxoODA / 13-oxoODA<1, Example 2) was applied.

[0116] The four components, glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid, are among those listed in Japanese Patent Publication No. 2020-174553 (Patent Document 2) as components whose increased content is an indicator of increased soybean yield. Therefore, increases in these four components indicate increased soybean yield. The results in Figures 1 to 4 show that applying a growth-promoting solution containing oxo fatty acids and terpenes increases soybean yield. Furthermore, it can be seen that a growth-promoting solution containing a relatively high amount of 9-oxoODA can more effectively increase soybean yield.

[0117] Furthermore, the results of Figure 5 show that gibberellins in soybean leaves were increased when the growth-promoting solution containing oxo fatty acids and terpenes (Examples 2 and 4) was applied compared to when the solution containing no terpenes (Comparative Example 2 and Test Example 2) was applied. Furthermore, the increase was greater when the growth-promoting solution containing a relatively high amount of 9-oxoODA (Example 4) was applied compared to when the growth-promoting solution containing a relatively high amount of 13-oxoODA (Example 2) was applied. Gibberellins are plant hormones that promote flower bud formation in soybeans. It can be seen that the growth-promoting solution containing oxo fatty acids and terpenes has the effect of increasing gibberellins in soybeans and, therefore, has the effect of increasing soybean yields.

[0118] 6, the gibberellin content in rice plants treated with the growth-promoting solution containing oxo fatty acids and terpenes (Examples 1 and 3) was higher than that in plants treated with the solution not containing terpenes (Comparative Example 1 and Test Example 1). Gibberellin is a plant hormone responsible for promoting flower bud formation in rice, and it can be seen that the growth-promoting solution containing oxo fatty acids and terpenes has the effect of increasing rice yields.

[0119] From the results of Figures 7 and 8, it can be seen that a composition consisting of a fatty acid without a carbonyl group, such as stearic acid, and a terpene has no effect on increasing gibberellin in soybeans, and is also unable to increase the four components, glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid, and therefore cannot be expected to be effective in increasing soybean yields.

Claims

1. A plant activator comprising at least one compound selected from oxo fatty acids or derivatives thereof or salts thereof, and a terpene.

2. The plant activator according to claim 1, wherein the oxo fatty acid is represented by the following formula (I) or the following formula (II). HOOC-(R 1 )-C β H=C α H-C(=O)-R 2 (I) In formula (I), R 1 represents a linear or branched, saturated or unsaturated hydrocarbon group containing 6 to 12 carbon atoms. R 2 represents an alkyl group having 2 to 8 carbon atoms, which may contain one or more branches and / or double bonds. C α is the α-carbon adjacent to the carbonyl group first on the R １ side, and C β is the β-carbon adjacent to the carbonyl group second on the R １ side. HOOC-(R 3 )-C(=O)-C α H=C β H-R 4 (II) In formula (II), R 3 represents a linear or branched, saturated or unsaturated hydrocarbon group containing 3 to 10 carbon atoms. R 4 represents a hydrocarbon group having 4 to 11 carbon atoms, which may contain one or more branches and / or double bonds. C α is the α-carbon adjacent to the carbonyl group first on the R ４ side, and C β is the β-carbon adjacent to the carbonyl group second on the R ４ side.

3. In the formula (I), R 1 is a double bond that forms a conjugated double bond with the double bond between the α-carbon C α and the β-carbon C β in the formula (I), and in the formula (II), R 4 is a double bond that forms a conjugated double bond with the double bond between the α-carbon C α and the β-carbon C β in the formula (II). The plant activator according to claim 2, which contains a double bond that forms a conjugated double bond with the double bond between the α-carbon C and the β-carbon C in the formula (II).

4. The plant activator according to claim 3, wherein the oxo fatty acid represented by the formula (I) and the oxo fatty acid represented by the formula (II) are keto octadecadienoic acid.

5. In the formula (I), R 1 is a linear or branched hydrocarbon group having 9 carbon atoms, and R 2 is an alkyl group having 5 carbon atoms, and in the formula (II), R 3 is a linear or branched hydrocarbon group having 7 carbon atoms, and R 4 is a plant activator according to claim 3, having a structure of CH3-CH2-CH2-CH2-CH2-CH=CH- and having 7 carbon atoms.

6. The plant activator according to claim 1, wherein the oxo fatty acid is at least one selected from the group consisting of 9-oxo-10,12-octadecadienoic acid, 13-oxo-9,11-octadecadienoic acid, 5-oxo-6,8-octadecadienoic acid, 6-oxo-9,12-octadecadienoic acid, 8-oxo-9,12-octadecadienoic acid, 10-oxo-8,12-octadecadienoic acid, 11-oxo-9,12-octadecadienoic acid, 12-oxo-9,13-octadecadienoic acid, and 14-oxo-9,12-octadecadienoic acid.

7. The plant activator according to claim 1, wherein the plant activator contains at least two or more oxo fatty acids.

8. The plant activator according to claim 2, comprising at least one oxo fatty acid represented by the formula (I) and at least one oxo fatty acid represented by the formula (II).

9. The plant activator according to claim 8, wherein the oxo fatty acid represented by the formula (I) is 13-oxo-9,11-octadecadienoic acid, and the oxo fatty acid represented by the formula (II) is 9-oxo-10,12-octadecadienoic acid.

10. The plant activator according to claim 9, wherein the ratio of the content of 9-oxo-10,12-octadecadienoic acid to the content of 13-oxo-9,11-octadecadienoic acid is 0.3 to 2.0 by weight ratio.

11. The plant activator according to claim 9, wherein the ratio of the content of 9-oxo-10,12-octadecadienoic acid to the content of 13-oxo-9,11-octadecadienoic acid is 1.0 to 2.0 by weight ratio.

12. The plant activator according to claim 1, which increases the production amount of at least one selected from the group consisting of 2-hydroxypyridine, glycine, L-pyroglutamic acid, and sucrose.

13. The plant activator according to claim 1, which increases the production amount of plant hormones.

14. The plant activator according to claim 13, wherein the plant hormone is gibberellin.

15. The plant activator according to claim 1, which is for promoting flower bud formation and / or improving yield.

16. The plant activator according to claim 1, wherein the terpene is a monoterpene.

17. The plant activator according to claim 1, which is a spray agent or an immersion agent to be brought into contact with the foliage or roots of plants, or an agent for soil perfusion.

18. The plant activator according to claim 1, which is a plant activator for Gramineae plants or a plant activator for Leguminosae plants.

19. The plant activator according to claim 1, further comprising a hydroxy fatty acid or a derivative thereof or a salt thereof.

20. The plant activator according to claim 19, wherein the hydroxy fatty acid is at least one selected from the group consisting of 9,10,13-trihydroxy-11-octadecenoic acid and 9,12,13-trihydroxy-10-octadecenoic acid.

Images