Plant Activator

Abstract

To provide a plant activator which has low soil pollution and toxicity and has an excellent plant growth acceleration effect.SOLUTION: Provided is a plant activator comprising a hydroxy fatty acid derivative, a salt thereof, or an ester thereof as an effective ingredient, the hydroxy fatty acid having a structural formula of HOOC-(R1)-CH(OH)-CH(OH)-CH=CH-CH(OH)-R2 (I) and / or HOOC-(R1)-CH(OH)-CH=CH-CH(OH)-CH(OH)-R2 (II) (in the formula, R1 is a linear or branched hydrocarbon group having 4 to 12 carbon atoms, which may contain 1 or more double bonds and / or hydroxy groups and, when it contains a double bond(s), the position thereof is not limited; and R2 is a linear or branched hydrocarbon group having 2 to 8 carbon atoms, which may contain 1 or more double bonds and / or hydroxy groups and, when it contains a double bond(s), the position thereof is not limited).SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] Since ancient times, for the purpose of promoting plant growth, measures such as optimizing temperature conditions, sunlight conditions, and fertilization have been taken. However, these measures have limitations. For example, even if the amount of fertilizer used for fertilization is increased, not only can no growth promotion effect beyond a certain level be expected, but if too much fertilizer is applied, it may instead become an obstacle to plant growth and may even contaminate the soil.

[0003]

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] There is a need for a plant activator that has a growth promotion effect superior to that of the plant activator containing ketol fatty acid as an active ingredient described in Patent Document 1 and the plant activator described in Patent Document 2, and is excellent in uniformity and dispersibility in perfusion and spraying.

[0006] ​An object of the present invention is to provide a plant activator that has low soil contamination and toxicity and excellent plant growth promoting effects.

Means for Solving the Problems

[0007] The present invention relates to the following formula (I) and / or (II): HOOC-(R 1 )-CH(OH)-CH(OH)-CH=CH-CH(OH)-R 2 (I) HOOC-(R 1 )-CH(OH)-CH=CH-CH(OH)-CH(OH)-R 2 (II) In the formula, R 1 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 containing a double bond, the position of the double bond is not limited. R 2 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 containing a double bond, the position of the double bond is not limited. The present invention relates to a plant activator characterized by containing a hydroxylated fatty acid derivative having the structural formula of 1 or a salt or ester thereof as an active ingredient. Here, in particular, R n is preferably -(CH2)

[0008] -(where n is an integer from 4 to 12). 1 The plant activator is preferably a hydroxylated fatty acid derivative in which the hydrocarbon group of R 2 of the hydroxylated fatty acid derivative has 6 to 8 carbon atoms and the hydrocarbon group of R

[0009] The hydroxylated fatty acid derivative is preferably a hydroxylated fatty acid derivative in which R 1 of the hydroxylated fatty acid derivative has a structure of -(CH2) n -(n is an integer from 4 to 12), and R2 But, C n H 2n+1 A plant activator that is a hydroxylated fatty acid derivative having the structure -(n is an integer of 2 to 8) is preferred.

[0010] The hydroxylated fatty acid derivative is R 1 is an alkylene group having 7 carbon atoms (-(CH2)7-), and R 2 However, a plant activator that is a hydroxylated fatty acid derivative having an alkyl group of 5 carbon atoms (CH3CH2CH2CH2CH2-) is preferred.

[0011] The plant activator is preferably such that the hydroxylated fatty acid derivative is hydroxyoctadecenoic acid.

[0012] The plant activator is preferably such that the hydroxylated fatty acid derivative is 9,10,13-trihydroxy-11-octadecenoic acid.

[0013] The plant activator is preferably such that the hydroxylated fatty acid derivative is 9,12,13-trihydroxy-10-octadecenoic acid.

[0014] In addition, "octadecaenoic acid" is a conventional notation (for example, JP-A-3-14539, etc.), and the above-mentioned "9,10,13-trihydroxy-11-octadecenoic acid" is also written as "9,10,13-trihydroxyoctadec-11-enoic acid" or "9,10,13-trihydroxy-11-octadecenoic acid". Similarly, the above-mentioned "9,12,13-trihydroxy-10-octadecenoic acid" is also written as "9,12,13-trihydroxyoctadec-10-enoic acid" or "9,12,13-trihydroxy-10-octadecenoic acid". In addition, in the examples, the manufacturer's name is also written in parentheses. In addition, the above explanation applies to all "octadecaenoic acid" used in this specification, claims, drawings and abstract.

[0015] The structural formula of “9,10,13-trihydroxy-11-octadecenoic acid” is shown in the following structural formula (1).

[0016]

Chem.

[0017] The structural formula of "9,12,13 - trihydroxy - 10 - octadecenoic acid" is shown by the following structural formula (2).

[0018]

Chem.

[0019] It is preferable that the plant activator is a plant activator further containing a surfactant and / or a diluent or a carrier.

[0020] A plant activator in which the concentration of the hydroxy fatty acid derivative or its salt or ester is 0.05 - 5 mg / L is preferable.

[0021] It is preferable that the plant activator is a plant activator used as a spray agent or an immersion agent for contacting the stems, leaves or roots of plants, or a chemical agent for soil perfusion.

[0022] It is preferable that the plant activator is a plant activator used for plants selected from the plants of the Brassicaceae, Poaceae, Fabaceae, Solanaceae, Rosaceae, Amaranthaceae, Cucurbitaceae, or Malvaceae families.

Advantages of the Invention

[0023] The plant activator of the present invention is easily decomposed in the environment, so it has low soil pollution and toxicity, and has an excellent plant growth promoting effect.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0025] Plant activator The plant activator of the present invention is a hydroxy fatty acid derivative, and has the following formula (I) and / or (II): HOOC-(R 1 )-CH(OH)-CH(OH)-CH=CH-CH(OH)-R 2 (I) HOOC-(R 1 )-CH(OH)-CH=CH-CH(OH)-CH(OH)-R 2 (II) In the formula, R 1 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 containing a double bond, the position of the double bond is not limited. R 2 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 containing a double bond, the position of the double bond is not limited. It is characterized by containing a hydroxy fatty acid derivative having the structural formula shown below, or a salt or ester thereof, as an active ingredient. In particular, R 1 is preferably -(CH2) n -(where n is an integer from 4 to 12). The present invention also relates to a plant activator containing, as an active ingredient, a compound of formula (I) and / or (II) including all geometric isomers and stereoisomers, or a salt or ester thereof.

[0026] "Plant activation" in the present invention means adjusting to activate or maintain the growth activities of plants in some way, and includes concepts such as growth promotion (a concept including the expansion of stems and leaves, the promotion of the growth of tubers and roots, etc.), dormancy inhibition, induction and imparting of resistance to plant stress (such as diseases, etc.), and plant growth regulation effects such as anti-aging. For example, by bringing the plant activator of the present invention into contact with a part of the stems, leaves or roots of a plant, a growth promotion effect can be imparted to the plant. By inoculating the plant activator of the present invention, in the plant body, compared with the untreated plant, an increase in the leaf length and leaf weight, which are plant growth indicators, and the promotion of the growth of tubers or roots are confirmed. Therefore, it is considered that the plant activator of the present invention imparts a growth promotion effect to the plant. By using the plant activator of the present invention, the growth of the plant body can be promoted, resulting in an increase in the yield of plant bodies such as vegetables, grains, fruits, etc. The plant growth promotion effect of the plant activator of the present invention is very high, and as a result, it can bring about an excellent yield increase effect and improved harvesting efficiency of commercial crops.

[0027] 9(S),10(S),13(S)-11(E)-trihydroxyoctadecenoic acid and / or 9(S),12(S),13(S)-10(E)-trihydroxyoctadecenoic acid and their derivatives, which are used as an example of the hydroxy fatty acid derivative in one embodiment of the present invention, are suitable as the plant activator of the present invention. In this specification, a hydroxy fatty acid or its derivative containing hydroxyoctadecenoic acid or its derivative is collectively referred to as a hydroxy fatty acid derivative for explanation.

[0028] Examples of the salts of the hydroxylated fatty acid derivative of the present invention include ammonium salts such as ammonium salts and alkylammonium salts such as tetramethylammonium salts, alkaline earth metal salts such as calcium salts and magnesium salts, alkali metal salts such as sodium salts, lithium salts and potassium salts, metal salts such as cobalt salts and manganese salts, and salts contained in fertilizers and the like. There is no particular limitation as long as it is one or more agriculturally acceptable salts. For example, by forming the hydroxylated fatty acid derivative in the form of a salt, high water solubility and / or low deliquescence may be obtained, and the handling of the hydroxylated fatty acid derivative may be facilitated. Further, in the present invention, the salt of the hydroxylated fatty acid derivative includes salts formed from the hydroxylated fatty acid derivative and an acid or a base, hydrates thereof, and salts of the hydroxylated fatty acid derivative in various forms such as mixtures thereof.

[0029] Examples of the esters of the hydroxylated fatty acid derivative of the present invention include, but are not limited to, methyl ester, ethyl ester, propyl ester, butyl ester, pentyl ester, isopentyl ester, octyl ester and the like.

[0030] As described later, the plant activator containing the hydroxylated fatty acid derivative of the present invention is characterized in that when applied to plants, it exhibits a significantly superior plant growth promoting effect on plants as compared with known plant growth promoting materials. This indicates that the plant activator of the present invention has a high plant growth promoting effect. It also shows that the disease of the plant is suppressed by the expression of resistance-inducing genes in the salicylic acid pathway and jasmonic acid pathway, which are immune mechanisms against diseases of the plant, when applied to the plant.

[0031] The plant activator of the present invention may contain, if necessary, a compatible surfactant and / or a diluent or carrier suitable for use in the plant activator. For example, the use of a diluent may improve the dispersibility of a hydroxy fatty acid derivative, such as hydroxyoctadecaenoic acid or its salt or ester, in a solvent. Further, in order to improve the solubility and dispersibility of the hydroxy fatty acid derivative used in the present invention in a diluent, surfactants such as a dispersion aid or a wetting agent may be contained. These additive components are not particularly limited as long as they are agriculturally acceptable agents. Further, the plant activator of the present invention may further contain, in addition to the hydroxy fatty acid derivative or its salt or ester, components commonly used in agricultural chemical formulations and other components beneficial to plants, such as one or more fertilizer components, etc., other than the surfactant, diluent, and carrier.

[0032] The plant activator of the present invention only needs to contain a hydroxy fatty acid derivative or its salt or ester, and their origin etc. are not particularly limited. The hydroxy fatty acid derivative or its salt or ester such as hydroxyoctadecaenoic acid of the present invention may be obtained, for example, by chemical synthesis, or may be, for example, those produced using microorganisms or those obtained by allowing a microorganism-derived enzyme to act on a substrate such as a fatty acid. The plant activator of the present invention only needs to contain a hydroxy fatty acid derivative at a desired concentration. For example, when hydroxyoctadecaenoic acid produced using microorganisms is used as the hydroxy fatty acid derivative, a mixture containing hydroxyoctadecaenoic acid may be used as the plant activator. When a biosurfactant secreted by a microorganism etc. is contained in the mixture, it may be possible to improve the dispersibility of the plant activator of the present invention without containing the additive components as described above. When the hydroxy fatty acid derivative itself is insoluble, it may be emulsified with a biosurfactant and dispersed in water.

[0033] The plant activator of the present invention can be applied to plants by any method. It is not particularly limited as long as it is a method of contacting the plant body such as the roots, stems, and leaves of the plant. It may be applied so as to directly contact the plant body, or may be applied to a cultivation carrier such as soil in which the plant body is established. For example, the plant activator of the present invention can be used as a spraying agent or dipping agent for contacting the stems and leaves or roots of plants, or a soil perfusion agent. Further, the plant activator of the present invention may be used as a sustained-release agent by being included in a porous structure or a capsule, or impregnated in a sheet or the like. Further, for storage stability, it may be powdered together with a suitable excipient by means of freeze-drying or spray-drying. The plant activator of the present invention imparts a plant growth promoting effect to plants, and in the applied plants, it increases the yield due to the increase in the plant body such as the increase in leaf length, plant weight, number of leaves, and crop weight, and improves the harvesting efficiency by increasing the number of stems per plant. Further, the expression of resistance genes suppresses plant diseases.

[0034] The plant activator of the present invention can promote plant growth by simple treatments such as spraying and can also suppress diseases, so there is no need to prepare special equipment or the like, and the present invention is very advantageous in this regard. Further, for example, hydroxyoctadecaenoic acid is an oxide of a naturally occurring fatty acid, so the plant activator of the present invention has a low environmental load and hardly causes phytotoxicity to the plants to which it is applied. In this regard, the plant activator of the present invention is excellent.

[0035] The application of the hydroxy fatty acid derivative or its salt or ester, which is the active ingredient of the plant activator of the present invention, to the plant body and / or cultivation carrier can be carried out, for example, by a method in which the hydroxy fatty acid derivative or its salt or ester is applied to the plant body and / or cultivation carrier in a liquid state dissolved or dispersed in water and / or a water-soluble solvent. For example, the liquid in which the hydroxy fatty acid derivative or its salt or ester is dissolved or dispersed can be sprayed or applied to the above-ground part (stems, leaves, etc.) of the plant body of the target plant. The application of the plant activator of the present invention to the target plant may be carried out at least once, for example, after germination and before harvesting, and may be applied in multiple portions.

[0036] In one embodiment of the present invention, the hydroxy fatty acid derivative or its salt or ester can be used at a concentration of 500 mg / L or less. The preferred concentration of the hydroxy fatty acid derivative or its salt or ester depends on the plant species to be applied and its condition. However, when the concentration exceeds 500 mg / L, there is a risk of phytotoxicity to the plant. The lower limit of the concentration of the hydroxy fatty acid derivative or its salt or ester is not particularly limited, but a concentration of 0.05 mg / L or more is preferred. In a preferred embodiment of the present invention, the concentration of the hydroxy fatty acid derivative or its salt or ester is 0.01 to 100 mg / L.

[0037] The plants to which the plant activator of the present invention can be applied are not particularly limited and can be preferably used for plants in general. For example, plants of the Gramineae, Leguminosae, Solanaceae, Rosaceae, Chenopodiaceae, Malvaceae, Cucurbitaceae or Brassicaceae families can be mentioned. For example, as plants of the Gramineae family, such as turfgrass, rice, wheat, corn, etc.; as plants of the Leguminosae family, such as soybean, broad bean, kidney bean, licorice, etc.; as plants of the Solanaceae family, such as tomato, eggplant, pepper, pea, potato, etc.; as plants of the Rosaceae family, such as strawberry, etc.; as plants of the Chenopodiaceae family, such as spinach, etc.; as plants of the Malvaceae family, such as cotton, okra, etc.; as plants of the Cucurbitaceae family, such as cucumber, pumpkin, watermelon, etc.; as plants of the Brassicaceae family, such as Komatsuna, Mizuna, etc. The growth of these plants is effectively promoted. Also, the plants to be applied are not limited to wild-type plants and may be, for example, mutants or transformants. Also, the varieties of each plant are not particularly limited.

Examples

[0038] The present invention will be described based on examples, but the present invention is not limited only to the examples.

[0039] Example 1 Growth evaluation of Mizuna As Example 1, a mixture of 9,10,13-trihydroxy-11-octadecenoic acid (manufactured by Larodan Fine Chemicals, 9(S),10(S),13(S)-trihydroxy-11(E)-octadecenoic acid in English notation, 9(S),10(S),13(S)-trihydroxy-11(E)-octadecenoic acid in Japanese notation), 200 mg / L ethanol solution), and 9,12,13-trihydroxy-10-octadecenoic acid (manufactured by Larodan Fine Chemicals, 9(S),12(S),13(S)-trihydroxy-10(E)-octadecenoic acid in English notation, 9(S),12(S),13(S)-trihydroxy-10(E)-octadecenoic acid in Japanese notation), 200 mg / L ethanol solution) mixed at a ratio of 2:1 was used as a trihydroxyoctadecenoic acid solution.

[0040] As a comparative example, a plant activator containing keto fatty acids and fatty acid metabolites prepared by the following method was used.

[0041] Preparation of keto fatty acids 10 mg of soybean-derived lipoxidase (manufactured by Sigma-Aldrich) was added to a linoleic acid suspension consisting of 1 g of linoleic acid, 0.15 g of potassium dihydrogen phosphate, and 100 mL of distilled water, and stirred for 24 hours to produce lipid peroxide 1. The production of lipid peroxide was confirmed by comparison with a standard substance by TLC (developing solvent chloroform:ethanol = 20:1, sulfuric acid coloring) and an increase in OD234nm. In addition, it was confirmed by NMR that the main component of lipid peroxide 1 is 13-HPODE ((9Z,11E)-13-(hydroperoxy)-9,11-octadecadienoic acid). 0.1 mg of allene oxide synthase (manufactured by Sigma-Aldrich) was added to the obtained peroxide substance 1 and stirred for 24 hours to obtain keto fatty acids. Then, dilute hydrochloric acid was added under ice-cooling to adjust the pH of the reaction solution to 3.0 to stop the enzyme reaction. The pH was adjusted to 6.5 to obtain an aqueous solution of keto fatty acids (9-hydroxy-10-oxo-12(Z),15(Z)-octadecadienoic acid, 13-KODA).

[0042] Preparation of a plant activator containing fatty acid metabolites <Pre-culture step> Dissolve 20 g of peptone (protein hydrolyzate manufactured by Difco), 1.5 g of magnesium sulfate heptahydrate, and 1.5 g of dipotassium hydrogen phosphate in 1 L of water in a glass Erlenmeyer flask, perform autoclave sterilization at 121 °C for 20 minutes, and after cooling to room temperature, inoculate a bacterial solution of Proteobacteria (a complex bacterial community containing Azoarcus buckelii, Propionivibrio pelophilus, Thauera selenatis, Pandoraea pulmonicola, Pusillimonas noertemannii, Rhodovulum kholense, Haematobacter massiliensis, Hyphomicrobium hollandicum, Chelatovorus multitrophus, Nitrosococcus halophilus, Thioalkalivibrio thiocyanodenitrificans, Marinobacter hydrocarbonoclasticus, Halomonas xinjiangensis, Pseudomonas pertucinogena, etc.) derived from activated sludge used in wastewater treatment. The mouth of the culture vessel was sealed with a silicone stopper. The inoculated vessel was cultured for 24 hours under the conditions of 20 °C and 120 rpm using a bioshaker (BR-23UM manufactured by Taitec Co., Ltd.). The number of bacteria in the culture solution was 5×10 8 cells / mL. After culturing, the cells were separated from the culture solution by centrifuging the culture solution at 15,000×G and 20 °C, and the cells were recovered. <Fatty acid metabolism step> To 1 L of sterilized water in a glass Erlenmeyer flask, 12 g of linoleic acid (primary linoleic acid manufactured by FUJIFILM Wako Pure Chemical Corporation), 1.5 g of magnesium sulfate heptahydrate, 1.5 g of dipotassium hydrogen phosphate, and the total amount of the bacterial cells obtained in the pre-culture step were added. This was cultured for 4 days using a Bioshaker (registered trademark) (BR-23UM manufactured by Taitec Corporation) under the conditions of 20°C, 120 rpm, and a dissolved oxygen concentration of 4 mg / L. The decomposition of linoleic acid was analyzed by measuring the absorbance at a wavelength of 230 nm using a spectrophotometer BioSpec-mini manufactured by Shimadzu Corporation, and confirmed by the production of oxidized lipids, which is one of the linoleic acid intermediate products. The culture solution containing the bacterial cells after culture was used as the fatty acid metabolite contained in the plant activator containing fatty acid metabolites.

[0043] To each of the above-obtained trihydroxyoctadecaenoic acid solution, keto-fatty acid aqueous solution, and culture solution containing fatty acid metabolites, distilled water was added so that the final concentrations of trihydroxyoctadecaenoic acid, keto-fatty acid, and fatty acid metabolites became 0.05 mg / L, and a dilution solution was prepared and used as a treatment solution. A 72-well cell tray was filled with culture soil (Takii Seed Co., Ltd., product name "seeding culture soil"), and seeds of sprouted watercress were sown. After germination, the watercress seedlings were thinned to 2 plants per cell. The light conditions were set to 12 hours of light period / 12 hours of dark period. Water was replenished by irrigating an appropriate amount of tap water about once every 4 days. 9 days and 12 days after sowing, each treatment solution was sprayed (300 L / 10a) onto the above-ground part of the plant using a spray for foliar application. No treatment solution was sprayed for the negative control ("untreated group").

[0044] It was harvested 21 days after sowing, and the wet weight of the above-ground part per plant and the leaf length were measured. The results are shown in FIGS. 1 and 2, respectively.

[0045] As shown in FIGS. 1 and 2, for the untreated plot, both the average above-ground wet weight and leaf length of water dropwort (n = 20) in the application plot of the treatment solution of hydroxyoctadecenoic acid increased. The above-ground wet weight was 0.35 g / plant in the hydroxyoctadecenoic acid treatment plot, as compared to 0.19 g / plant in the untreated plot. Also, the leaf length was 9.6 cm in the hydroxyoctadecenoic acid treatment plot, as compared to 8.1 cm in the untreated plot. As a result of the t-test, for both the above-ground wet weight and leaf length, a significant difference was observed in the application plot of the treatment solution of hydroxyoctadecenoic acid as compared to the untreated plot. In contrast, in the application plot using a fatty acid metabolite or keto acid as the treatment solution, almost no increase in the above-ground wet weight was observed. Also, in the application plot of the keto fatty acid treatment solution, the leaf length decreased.

[0046] Example 2 Growth Evaluation of Spinach A 72-hole cell tray was filled with cultivation soil (Takii Seed Co., Ltd., product name "Seeding Cultivation Soil"), and spinach seeds that had been germinated were sown. After germination, the spinach seedlings were thinned to 2 plants per cell. The light conditions were set to 12 hours of light period / 12 hours of dark period. Water was replenished by pouring an appropriate amount of tap water about once every 3 days. Using the treatment solution of hydroxyoctadecenoic acid prepared in Example 1 as the treatment solution, 16 days after sowing, the treatment solution was sprayed onto the above-ground part of the plant body by spray (300 L / 10a) for foliar application. No treatment solution was sprayed for the negative control ("untreated plot").

[0047] The plants were harvested 23 days after sowing, and the above-ground wet weight per plant and the leaf length were measured. The results are shown in FIGS. 3 and 4, respectively.

[0048] As shown in FIGS. 3 and 4, for the untreated group, both the average above-ground wet weight and leaf length of spinach (n = 46) in the application area of the treatment solution of hydroxyoctadecaenoic acid increased. The above-ground wet weight was 0.26 g / plant in the hydroxyoctadecaenoic acid treatment group, compared to 0.20 g / plant in the untreated group. Also, the leaf length was 5.7 cm in the hydroxyoctadecaenoic acid treatment group, compared to 5.2 cm in the untreated group. As a result of the t-test, for both the above-ground wet weight and leaf length, a significant difference was observed in the application area of the treatment solution of hydroxyoctadecaenoic acid compared to the untreated group.

[0049] As shown in FIGS. 1 to 4, an increase in the above-ground wet weight and an increase in leaf length were confirmed for watercress, which is a Brassicaceae plant, and spinach, which is a Chenopodiaceae plant. It can be seen that the plant activator of the present invention has an excellent growth promoting effect on plants.

[0050] Example 3 Evaluation of Resistance Induction in Tomatoes Distilled water was added to the trihydroxyoctadecaenoic acid (trihydroxyoctadecenoic acid) solution (ethanol solution of a mixture of 9,10,13-trihydroxy-11-octadecaenoic acid and 9,12,13-trihydroxy-10-octadecaenoic acid) prepared in the previous stage of Example 1 so that the final concentration of trihydroxyoctadecaenoic acid became 5 mg / L (5 ppm) and 50 mg / L (50 ppm), and dilution solutions were prepared as two types of treatment solutions.

[0051] Tomato seedlings at the two-leaf stage of the true leaves (variety: CF House Momotaro; purchased from Ibi River Industry Co., Ltd.) were transplanted into 9 cm pots filled with culture soil (Takii Seedlings Co., Ltd., product name "Sowing Culture Soil"). The temperature was kept constant at 30°C, and the light conditions were set to 12 hours of light period / 12 hours of dark period with fluorescent lamps. Water was replenished by pouring an appropriate amount of tap water about once a day. Twenty-four hours after transplantation, the two types of treatment solutions of hydroxyoctadecaenoic acid prepared above were sprayed (10 mL / plant) on the above-ground part of the plant body by spraying for foliar application. Distilled water was sprayed for the negative control ("untreated group").

[0052] Forty-eight hours after foliar spraying, RNA was extracted from the true leaves of each tomato treated with each treatment solution and untreated tomatoes as a control using a commercially available RNA extraction kit (GPR1002, manufactured by Viogene), and cDNA was prepared from the RNA. The expression levels of resistance genes PR-1b, PR-2a, PR-2b, PR-3a, PR-3b, and PR-5 were examined by real-time PCR. The gene expression levels were normalized by the expression levels of housekeeping genes. For each treatment group, three tomato seedlings were tested, and the results of the average values of the obtained expression levels are shown in Figure 5. The types of resistance genes measured were referred to "Journal of Japanese Society of Plant Pathology, 2017, Vol. 83, p. 3-9". PR-1b, PR-2a, PR-3a, and PR-5 are resistance genes in the salicylic acid pathway, and PR-2b and PR-3b are resistance genes in the jasmonic acid pathway.

[0053] Example 4 Evaluation of Resistance Induction in Cucumber Distilled water was added to the trihydroxyoctadecenoic acid (trihydroxyoctadecenoic acid) solution (ethanol solution of a mixture of 9,10,13-trihydroxy-11-octadecenoic acid and 9,12,13-trihydroxy-10-octadecenoic acid) prepared in the previous stage of Example 1 so that the final concentration of trihydroxyoctadecenoic acid was 50 mg / L (50 ppm) to prepare a dilution, which was used as a treatment solution.

[0054] Cucumber seedlings at the two-leaf stage of true leaves (cultivar: Hokushin; purchased from Ibi River Industry Co., Ltd.) were transplanted into 9-cm pots filled with culture soil (Takii Seedlings Co., Ltd., product name "Sowing Culture Soil"). The temperature was kept constant at 25 °C, and the light conditions were set to 12 hours of light period / 12 hours of dark period with fluorescent lamps. Water was replenished by irrigating an appropriate amount of tap water about once a day. Five days after transplantation, the above-prepared treatment solution of hydroxyoctadecenoic acid was sprayed (10 mL / plant) on the above-ground part of the plant by spray for foliar spraying. Distilled water was sprayed for the negative control ("untreated group").

[0055] The expression levels of resistance genes PR-8 and POX were examined in cucumbers treated with the treatment solution 72 hours after foliar spraying and in untreated cucumbers as a control, using the same procedure as in Example 3. For each treatment group, three cucumber seedlings were tested, and the results of the average values of the obtained expression levels are shown in Fig. 6. The types of resistance genes measured were based on "Journal of Plant Molecular Breeding, 2016, Vol. 4, No. 2, p. 33-40" and "Horticultural Science Research, 2011, Vol. 10, No. 3, p. 429-433". PR-8 and POX are resistance genes in the salicylic acid pathway.

[0056] Example 5 Evaluation of Resistance Induction in Arabidopsis thaliana Distilled water was added to the trihydroxyoctadecenoic acid (trihydroxyoctadecenoic acid) solution (ethanol solution of a mixture of 9,10,13-trihydroxy-11-octadecenoic acid and 9,12,13-trihydroxy-10-octadecenoic acid) prepared prior to Example 1 so that the final concentration of trihydroxyoctadecenoic acid was 4 mg / L (4 ppm) and 40 mg / L (40 ppm), respectively, to prepare two types of treatment solutions.

[0057] Seeds of Arabidopsis thaliana (Col-0; purchased from Plant Innovation Co., Ltd.) were sown at a cultivation density of 1 plant / 1 cm in rock wool (Rockwool block 60P, manufactured by Daiwa Plastics Co., Ltd.) of 3 cm × 3 cm × 3 cm as a solid medium. 2 The temperature was kept constant at 22°C, and the light conditions were set to 12 hours of light period / 12 hours of dark period with fluorescent lamps. For 15 days after sowing, the rock wool was immersed in a culture solution obtained by diluting a commercially available liquid fertilizer (Vegeful liquid fertilizer, manufactured by Sumitomo Chemical Horticulture Co., Ltd.) 1000-fold and grown by hydroponics. After 15 days, 13 mL of the two types of hydroxyoctadecenoic acid treatment solutions prepared above were added to the rock wool, allowed to stand for 5 hours, and then replaced with the original culture solution for continuous growth. The negative control was untreated (the "non-treatment group").

[0058] After 24 hours of treatment, the expression levels of the resistance genes PR-1, PR-2, and PDF1.2 were examined in Arabidopsis thaliana treated with each treatment solution and untreated Arabidopsis thaliana as a control, using the same procedure as in Example 3. For each treatment group, three Arabidopsis thaliana seedlings were tested, and the results of the average expression levels obtained are shown in Fig. 7. The types of resistance genes measured were based on "PLoS ONE, Vol. 9, No. 1, e86882". PR-1 and PR-2 are resistance genes in the salicylic acid pathway, and PDF1.2 is a resistance gene in the jasmonic acid pathway.

[0059] As can be seen from Fig. 5 (Example 3), Fig. 6 (Example 4), and Fig. 7 (Example 5), an increase in the expression levels of resistance genes was confirmed in Solanaceae tomatoes, Cucurbitaceae cucumbers, and Brassicaceae Arabidopsis thaliana. It can be understood that the plant activator of the present invention has an excellent disease control effect on plants.

[0060] From the above results, it can be understood that the plant activator of the present invention is an excellent plant activator that has low soil pollution and toxicity, can promote plant growth, and can also suppress plant diseases by expressing resistance genes.

Claims

1. The following formula (I) and / or (II): HOOC-(R 1 )-CH(OH)-CH(OH)-CH=CH-CH(OH)-R 2 (I) HOOC-(R 1 )-CH(OH)-CH=CH-CH(OH)-CH(OH)-R 2 (II) In the formula, R 1 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 containing a double bond, the position of the double bond is not limited. R 2 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 containing a double bond, the position of the double bond is not limited. A plant activator characterized by containing, as an active ingredient, a hydroxylated fatty acid derivative having the structural formula of or a salt or ester thereof, The hydroxylated fatty acid derivative is 9,10,13-trihydroxy-11-octadecenoic acid and / or 9,12,13-trihydroxy-10-octadecenoic acid, and is a plant activator for promoting the expansion of stems and leaves or the growth of tubers and tuberous roots.

2. The plant activator according to claim 1, further comprising a surfactant and / or a diluent or carrier.

3. The plant activator according to claim 1 or 2, wherein the concentration of the hydroxylated fatty acid derivative or a salt or ester thereof is 0.05 to 5 mg / L.

4. The plant activator according to any one of claims 1 to 3, which is used as a spraying agent or dipping agent for contacting the stems, leaves or roots of plants, or a chemical agent for soil perfusion.

5. The plant activator according to any one of claims 1 to 4, wherein the plant activator is used for plants selected from the group consisting of Brassicaceae, Poaceae, Fabaceae, Solanaceae, Rosaceae, Amaranthaceae, Cucurbitaceae, or Malvaceae plants.

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