Plant activator for soybeans

Abstract

The objective is to provide a plant activator for soybeans that can increase soybean yield. [Solution] A plant activator for soybeans comprising at least one compound selected from ketooctadecadienoic acid or its derivatives, structural isomers, or salts thereof.

Description

[Technical Field]

[0001] This invention relates to a plant activator for soybeans. [Background technology]

[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 have been reported for revitalizing plants using plant stimulants that have plant growth regulating effects such as growth promotion, dormancy suppression, and stress reduction.

[0003] Patent Document 1 discloses a method for efficiently producing ketooctadecadienoic acid, a functional ingredient known to exhibit fat-burning effects, using enzymes. It also states that the obtained ketooctadecadienoic acid can be used as a plant activator exhibiting a strong resistance-inducing effect.

[0004] Patent Document 2 discloses a method for predicting soybean yield early by obtaining analytical data of one or more components selected from the metabolites contained in the leaves of a soybean sample to be predicted, namely 2-hydroxypyridine, choline, citric acid, glyceric acid, glycine, L-pyroglutamic acid, malonic acid, sucrose, and threitol, and comparing this 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-inducing effect. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-25534 [Patent Document 2] Japanese Patent Publication No. 2020-174553 [Patent Document 3] International Publication No. 2018 / 168860 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Patent documents 1 and 3 do not describe plant activators for soybeans to increase soybean yield in soybean cultivation. Furthermore, while patent document 2 states that predicting soybean yield can significantly improve the efficiency of developing yield-increasing technologies, it does not disclose any specific yield-increasing technologies.

[0008] Soybeans are an important grain, a staple in traditional foods, and their functional components are also attracting attention. However, the supply of soybeans is unstable, and there is a need to improve productivity by increasing yields and stabilizing quality. While techniques such as irrigation, top dressing during the growing season, and foliar application of urea are known to be effective in increasing soybean yields, ensuring a stable increase in yield remains difficult. Therefore, there is a need for efficient yield-increasing agents that can lead to higher yields.

[0009] This invention has been made in view of the above-mentioned problems, and aims to provide a plant activator for soybeans that can safely, stably, and effectively increase soybean yield by being appropriately sprayed or drenched on soybeans. [Means for solving the problem]

[0010] The present invention relates to a plant activator for soybeans comprising at least one compound selected from ketooctadecadienoic acid or its derivatives, structural isomers, or salts thereof.

[0011] It is preferable that the keto-octadecadienoic 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.

[0012] It is preferable that the plant activator for soybeans contains at least 9-oxo-10,12-octadecadienoic acid.

[0013] It is preferable that the plant activator for soybeans contains at least two or more keto-octadecadienoic acids.

[0014] It is preferable that the plant activator for soybeans contains 13-oxo-9,11-octadecadienoic acid and 9-oxo-10,12-octadecadienoic acid.

[0015] For the plant activator for soybeans, it is preferable that the ratio of the content of 9-oxo-10,12-octadecadienoic acid to the content of 13-oxo-9,11-octadecadienoic acid is greater than 1 in weight ratio.

[0016] For the plant activator for soybeans, it is preferable that the ratio of the content of 9-oxo-10,12-octadecadienoic acid to the content of 13-oxo-9,11-octadecadienoic acid is greater than 1.5 in weight ratio.

[0017] It is preferable that the plant activator for soybeans is a plant activator for soybeans that increases the production amount of at least one selected from the group consisting of 2-hydroxypyridine, glycine, L-pyroglutamic acid, and sucrose.

[0018] It is preferable that the plant activator for soybeans is a plant activator for soybeans that increases the production amount of plant hormones.

[0019] It is preferable that the plant activator for soybeans is such that the plant hormone is cytokinin and / or gibberellin.

[0020] It is preferable that the plant activator for soybeans is for preventing pod drop and / or promoting flower bud formation and / or improving yield.

[0021] It is preferable that the plant activator for soybeans is a spraying agent or dipping agent that comes into contact with the stems, leaves or roots of soybeans, or a chemical agent for soil perfusion.

[0022] It is preferable that the plant activator for soybeans further contains a hydroxylated fatty acid or its derivative or its salt.

[0023] It is preferable that the hydroxylated 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.

[0024] Note that "octadecenoic acid" is a conventional notation (for example, Japanese Patent Laid-Open No. 3-14539, etc.), and the above-mentioned "9,10,13-trihydroxy-11-octadecenoic acid" is also denoted as "9,10,13-trihydroxyoctadec-11-enoic acid" or "9,10,13-trihydroxy-11-octadecenoic acid". The structural formula of "9,10,13-trihydroxy-11-octadecenoic acid" is shown by the following structural formula (1).

[0025]

Chemical formula

[0026] Similarly, the aforementioned "9,12,13-trihydroxy-10-octadecaenoic acid" can also be written as "9,12,13-trihydroxyoctadeca-10-enoic acid" or "9,12,13-trihydroxy-10-octadecenoic acid". The structural formula of "9,12,13-trihydroxy-10-octadecaenoic acid" is shown in structural formula (2) below.

[0027] [ka] [Effects of the Invention]

[0028] The plant activator for soybeans of the present invention has a high effect in preventing pod drop and promoting flower bud formation, as well as an excellent effect in increasing yield. [Brief explanation of the drawing]

[0029] [Figure 1] This figure shows the results of the glycine analysis in soybean leaves. [Figure 2] This figure shows the results of the sucrose analysis in soybean leaves. [Figure 3] This figure shows the results of the analysis of 2-hydroxypyridine in soybean leaves. [Figure 4] This figure shows the results of the analysis of L-pyroglutamic acid in soybean leaves. [Figure 5] This figure shows the results of the cytokinin analysis in soybean leaves. [Figure 6] This figure shows the results of the gibberellin analysis in soybean leaves. [Modes for carrying out the invention]

[0030] Plant activator for soybeans The plant activator for soybeans of the present invention comprises at least one compound selected from ketooctadecadienoic acid or its derivatives, structural isomers, or salts thereof.

[0031] In this invention, "plant activation" means adjusting the growth activity of plants in some way to activate or maintain it, and is a concept that includes growth promotion (a concept that encompasses the expansion of stems and leaves, the promotion of tuber and root growth, etc.), dormancy suppression, induction and conferral of resistance to plant stress (e.g., diseases), and plant growth regulatory effects such as anti-aging.

[0032] As shown in the examples below, when the soybean plant activator of the present invention is applied to soybeans, the content of several components known to correlate with and guide yield increase is increased. Furthermore, plant hormones that promote flower bud formation and ovary growth, as well as plant hormones that are involved in the pod formation rate within soybean flower clusters and are said to prevent flower and pod drop due to the cessation of flower development, which is one of the limiting factors for soybean yield, can be increased. Therefore, in the present invention, the "plant activation" effect can mean, in particular, the effect of increasing soybean yield by promoting soybean growth and increasing the grain weight and number of grains per individual. The plant activation effect of the soybean 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 in soybeans.

[0033] The plant activator for soybeans of the present invention contains ketooctadecadienoic acid or its derivatives, structural isomers, or salts thereof as active ingredients for activating plants.

[0034] In this specification, the term "isomer" refers to various compounds that have the same molecular formula but differ in the arrangement and configuration of their atoms. Furthermore, as used herein, the term "structural isomer" refers to various compounds that have the same number and types of atoms but differ in their atomic bonding. For example, structural isomers of ketooctadecadienoic acid may include those with different positions of double bonds or carbonyl groups, such as linear or branched structures.

[0035] Furthermore, ketooctadecadienoic acid includes all stereoisomers having the same structural formula. As used herein, the term "stereoisomer" refers to any of the various stereoisomer configurations that may be present in the compounds of this disclosure, including geometric isomers. For example, the ketooctadecadienoic acid of this disclosure contains a double bond, where the substituent may be in an E or Z configuration.

[0036] For example, specific examples of ketooctadecadienoic acid 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. In this specification, "active ingredient" means ketooctadecadienoic acid, including the specific examples listed. Ketooctadecadienoic acid has properties that activate plant growth, and by bringing the soybean plant activator of the present invention, which contains ketooctadecadienoic acid or its derivatives, structural isomers, or salts thereof as an active ingredient, into contact with the stems, leaves, or roots of soybeans, the yield of soybeans can be improved. Preferably, the soybean plant activator of the present invention contains at least 9-oxo-10,12-octadecadienoic acid (9-oxoODA) as an active ingredient.

[0037] As a derivative of the aforementioned ketooctadecadienoic acid, an ester is preferred. The esters of ketooctadecadienoic acid of the present invention are not limited to these, but include methyl esters, ethyl esters, propyl esters, butyl esters, pentyl esters, isopentyl esters, octyl esters, and the like.

[0038] The salt of ketooctadecadienoic acid is not particularly limited as long as it is one or more agriculturally acceptable salts, such as alkali metal salts like sodium salt and potassium salt, or ammonium salts like alkylammonium salts such as ammonium salt and tetramethylammonium salt.

[0039] The soybean plant activator of the present invention may contain at least two types of ketooctadecadienoic acid as an active ingredient. By combining two or more types of ketooctadecadienoic acid, the soybean plant activator of the present invention may exhibit an even higher plant activating effect. For example, the two types of ketooctadecadienoic acid may be a combination of 9-oxo-10,12-octadecadienoic acid (9-oxoODA) and 13-oxo-9,11-octadecadienoic acid (13-oxoODA).

[0040] In one embodiment of the present invention, the plant activator for soybeans comprises 13-oxo-9,11-octadecadienoic acid or its salt or derivative and 9-oxo-10,12-octadecadienoic acid or its salt or derivative as ketooctadecadienoic acid. For example, the ratio of the content of 9-oxo-10,12-octadecadienoic acid or its salt or derivative to the content of 13-oxo-9,11-octadecadienoic acid or its salt or derivative can be greater than 1 by weight. Preferably, the ratio of the content of 9-oxo-10,12-octadecadienoic acid or its salt or derivative to the content of 13-oxo-9,11-octadecadienoic acid or its salt or derivative can be greater than 1.5 by weight.

[0041] For example, in one embodiment of the soybean plant activator of the present invention, ketooctadecadienoic acid or its derivatives, structural isomers, or salts thereof may be used at a concentration of 5 mg / L or less. The preferred concentration of ketooctadecadienoic acid or its derivatives, structural isomers, or salts thereof depends on the cultivation conditions and growth stage of the soybeans to which it is applied, the timing and method of application of the soybean plant activator, etc., and can be appropriately set to suit the application rate, however, if the concentration exceeds 5 mg / L, there is a risk of phytotoxicity to the soybeans. The lower limit of the concentration of ketooctadecadienoic acid or its derivatives, structural isomers, or salts thereof is not particularly limited, but 0.05 mg / L or higher is preferred. In one preferred embodiment of the present invention, the concentration of ketooctadecadienoic acid or its derivatives, structural isomers, or salts thereof is 0.05 to 5 mg / L.

[0042] The soybean plant activator of the present invention may optionally contain a compatible surfactant and / or diluent or carrier suitable for use as a plant activator. For example, a diluent may improve the dispersibility of ketooctadecadienoic acid or its derivatives, structural isomers, or salts thereof in a solvent. Furthermore, surfactants such as dispersing aids and wetting agents may be included to improve the solubility and dispersibility of the ketooctadecadienoic acid derivative used in the present invention in diluents. These additive components are not particularly limited as long as they are agriculturally acceptable drugs. In addition to surfactants, diluents, and carriers, the soybean plant activator of the present invention may also contain other components commonly used in pesticide formulations, such as pH adjusters, spreading agents to enhance adhesion to plants or soil, binders, antioxidants, and other components beneficial to plants, such as one or more fertilizer components.

[0043] The plant activator for soybeans of the present invention may contain ketooctadecadienoic acid or its derivatives, structural isomers, or salts thereof, and their origin is not particularly limited. The ketooctadecadienoic acid or its derivatives, structural isomers, or salts thereof of the present invention may be obtained, for example, by chemical synthesis, or may be produced, for example, using microorganisms, or obtained by reacting enzymes derived from microorganisms with a substrate such as fatty acids. The plant activator of the present invention may contain a desired concentration of ketooctadecadienoic acid derivative, and for example, if ketooctadecadienoic acid produced using microorganisms is used as the ketooctadecadienoic acid derivative, a mixture containing ketooctadecadienoic acid may be used as the plant activator. If biosurfactants secreted by microorganisms are included in the mixture, it may be possible to improve the dispersibility of the plant activator of the present invention without including the aforementioned additive components. If the ketooctadecadienoic acid derivative itself is insoluble, it may be possible to emulsify it with biosurfactants and disperse it in water.

[0044] In one embodiment of the present invention, the plant activator for soybeans may further contain, in addition to ketooctadecadienoic acid or its derivatives, structural isomers, or salts thereof as an active ingredient, hydroxylated fatty acids or their derivatives or salts thereof. A plant activator for soybeans with even higher activation effect may be obtained.

[0045] Hydroxylated fatty acids or their derivatives or salts thereof having the structural formulas shown in the following formulas (I) and / or (II) can be preferably used. HOOC-(R 1 )-CH(OH)-CH(OH)-CH=CH-CH(OH)-R 2 (I), and / or HOOC-(R 1 )-CH(OH)-CH=CH-CH(OH)-CH(OH)-R 2 (II) (In equations (I) and / or (II), R 1is a linear or branched hydrocarbon group having 4 to 12 carbon atoms, which may contain one or more double bonds and / or OH groups. 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. When containing a double bond, the position of the double bond is not limited).

[0046] In addition, as derivatives and salts of hydroxylated fatty acids, those exemplified above as derivatives or salts of keto octadecadienoic acid can be preferably used. Further, the hydroxylated fatty acids of the present disclosure include all geometric isomers and stereoisomers of the compounds represented by formula (I) and / or (II).

[0047] In one embodiment of the present invention, R in the above formula (I) and / or (II) 1 has a hydrocarbon group having 6 to 8 carbon atoms, and R 2 has a hydrocarbon group having 4 to 6 carbon atoms. In another embodiment, R in the above hydroxylated fatty acid 1 is -(CH2) n -(n is an integer from 4 to 12), and R 2 is C n H 2n+1 -(n is an integer from 2 to 8). Further, in another embodiment, R in the above hydroxylated fatty acid 1 is an alkylene group having 7 carbon atoms (-(CH2)7-), and R 2 is preferably an alkyl group having 5 carbon atoms (CH3CH2CH2CH2CH2-).

[0048] Preferably, the hydroxylated fatty acids 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 are not limited thereto.

[0049] As described above, the plant activator for soybeans of the present invention, which contains at least one compound selected from ketooctadecadienoic acid or its derivatives, structural isomers, or salts thereof, is characterized by exhibiting a remarkably excellent plant activating effect that promotes soybean growth and increases soybean yield when applied to soybeans. Compounds such as 2-hydroxypyridine, glycine, L-pyroglutamic acid, and sucrose, which are contained in soybean leaves, are known to have a good correlation with increased soybean yield, and an increase in their content is considered an indicator of increased soybean yield. These components are metabolites of soybeans, and there is a positive correlation between their abundance in the leaves and soybean yield.

[0050] The soybean plant activator of the present invention can increase the content of 2-hydroxypyridine, glycine, L-pyroglutamic acid, and / or sucrose in the leaves of soybeans to which it is applied. This result indicates that the soybean plant activator of the present invention can promote soybean growth and increase the grain weight and number of grains per plant. In other words, the soybean plant activator of the present invention is a soybean yield increaser. Note that "yield increase" for soybeans means an increase in the number of grains (beans) harvested from soybeans, for example, that the grain weight and / or number of grains per plant are greater than in a group of soybeans not treated with the soybean plant activator of the present invention.

[0051] The soybean plant activator of the present invention can also increase the content of plant hormones in the leaves of soybeans to which it is applied, which is associated with increased soybean yield. For example, the soybean plant activator of the present invention can increase the content in the leaves of gibberellin, a plant hormone that has physiological effects of promoting soybean flower bud formation and ovary growth. It is known that soybean 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 the development of flower clusters, can result in an increase in the number of flower buds, the number of pods, and thus the yield. In other words, the soybean plant activator of the present invention can induce an increase in gibberellin biosynthesis, i.e., it is a soybean flower bud formation promoter.

[0052] Furthermore, the plant activator for soybeans of the present invention can increase the content of cytokinin in the leaves, for example, which is a plant hormone that has physiological effects such as suppressing flower and pod drop and promoting pod elongation in soybeans. In soybeans, it is known that after flower bud differentiation, the floral organs stop developing or fall off during the developmental process, and the proportion that ultimately develop into fertile pods is relatively low. In other words, one of the causes of reduced soybean yield is the decrease in the number of pods due to flower and pod drop. Therefore, increasing the amount of cytokinin, which can suppress flower and pod drop and improve the pod setting rate, can result in an increase in yield. That is, the plant activator for soybeans of the present invention can induce an increase in cytokinin biosynthesis, i.e., it is a soybean pod drop prevention promoter.

[0053] The soybean plant activator of the present invention can be applied to soybeans by any method. The application method is not particularly limited as long as it involves contact with the plant body such as the roots, stems, and leaves of the soybean, and it acts suitably as an activator for preventing pod drop and / or promoting flower bud formation and / or improving yield in soybean cultivation. The soybean plant activator of the present invention may be applied so as to be in direct contact with the plant body, or it may be applied to the cultivation carrier such as soil or growing medium on which the plant body has been established. For example, the soybean plant activator of the present invention can be used as a spray or dipping agent that comes into contact with the stems, leaves, or roots of the plant, or as a soil drenching agent. Specific application methods can be appropriately selected depending on the cultivation form of the soybeans to be treated, but examples include ground liquid application, ground solid application, aerial liquid application, aerial solid application, surface application, application in a facility, soil mixing application, soil drenching application, surface treatment such as coating, seedling box application, single flower treatment, and base treatment. Furthermore, the soybean plant activator of the present invention may be mixed with plant fertilizer components and used as a plant fertilizer. The soybean plant activator of the present invention may also be encapsulated in porous structures or capsules, or impregnated into sheets, etc., and used as a sustained-release agent. The form of the soybean plant activator of the present invention is not particularly limited. The soybean plant activator of the present invention may be in liquid or gel form, or in solid form (block, powder, granules, etc.). In the case of a liquid composition, it can be used as is or as a concentrated type after dilution. The soybean plant activator of the present invention imparts a plant growth promoting effect to plants during soybean cultivation, resulting in increased soybean yield due to increased plant body size, such as increased crop weight, and improved soybean yield and harvesting efficiency by preventing pod drop and / or promoting flower bud formation.

[0054] The soybean plant activator of the present invention can improve soybean yield through simple treatments such as spraying, eliminating the need for special equipment, and is therefore highly advantageous in this respect as well. Furthermore, since ketooctadecadienoic acid and the like are oxides of naturally occurring fatty acids, the soybean plant activator of the present invention has a low environmental impact and causes almost no phytotoxicity to the plants it is applied to, making it superior in these respects as well.

[0055] The application of the soybean plant activator of the present invention to soybean plants and / or cultivation carriers can be carried out, for example, by applying ketooctadecadienoic acid or its derivatives, structural isomers, or salts thereof in a liquid state in which it is dissolved or dispersed in water and / or a water-soluble solvent. For example, a liquid in which ketooctadecadienoic acid or its derivatives, structural isomers, or salts thereof is dissolved or dispersed can be sprayed or applied to the above-ground parts (stem, leaves, etc.) of the target soybean plant. The application of the soybean plant activator of the present invention to the target plant only needs to be carried out at least once before the flowering period, for example, but may be carried out in multiple applications.

[0056] In this specification, "soybean" refers to the soybean (scientific name: Glycine max), an annual plant of the legume family. Although there are many varieties of soybeans, the soybean plant activator of the present invention can be suitably used with any of the following: domestic soybeans such as Fukuyutaka, Enrei, Sato no Hohoemi, Yuagari Musume, Ryuhou, Suzuyutaka, Toyohomare, Miyagishirome, etc., and US soybeans such as IOM. Furthermore, it is not a concern whether the soybeans are genetically modified or not. [Examples]

[0057] The present invention will be described based on examples, but the present invention is not limited to these examples.

[0058] [Example 1] • Preparation of growth-promoting solution As a raw material containing fatty acids, 580g of 90% pure linoleic acid (manufactured by NOF Corporation) was used. To this, 216g of potassium carbonate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 280g of dipotassium hydrogen phosphate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 13,000mL of distilled water were added to prepare the test solution. The pH of the test solution at this time was 9.0.

[0059] 40 mg of lipoxygenase (Nacalai Tesque Co., Ltd., derived from soybeans) was added to the test solution and reacted 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 adjust the pH to 7.0. This solution was reacted at 50°C for 22 hours with oxygen aeration and stirring, and then the reaction mixture was placed in a 90°C water bath for 2 hours.

[0060] The reaction solution obtained after the reaction was completed was used as a standard substance, along with 13-oxoODA (13-oxo-9,11-octadecadienoic acid), 9-oxoODA (9-oxo-10,12-octadecadienoic acid), and 9,10,13-trihydroxy-11-octadecadienoic acid (9,10,13-trihydroxy-11-octadecenoic acid), 9,10,13-trihydroxy-10-octadecenoic acid (9,10,13-trihydroxy-10-octadecenoic acid), and 9,12,13-trihydroxy-10-octadecenoic acid (9,12,13-trihydroxy-10-octadecenoic acid), manufactured by Cayman Chemical Corporation. MS (using acid) 2 Quantitative analysis was performed using LC-MS with spectral analysis. Additionally, ketooctadecadienoic acid (13-oxoODA, 9-oxoODA) was quantified using the absolute calibration curve method at a detection wavelength of UV 272 nm, and trihydroxyoctadecadienoic acid was quantified using the detection wavelength of UV 210 nm.

[0061] The combined yield of isomers such as (E,E) and (E,Z) was 3.3% for 13-oxoODA. The yield of 9-oxoODA was 6.5%. The combined yield of 9,10,13-trihydroxy-11-octadecaenoic acid and 9,12,13-trihydroxy-10-octadecaenoic acid was 0.63% (peaks could not be separated by LC-MS), and the recovery rate of linoleic acid was 80.2%.

[0062] The yield (%) was calculated based on the following formula. Yield (%) = (wt%) of 13-oxoODA, 9-oxoODA, 9,10,13-trihydroxy-11-octadecaenoic acid or 9,12,13-trihydroxy-10-octadecaenoic acid produced / (initial wt%) of linoleic acid used as the starting material

[0063] 0.1 mL of the reaction solution obtained above was diluted with ion-exchanged water to 2000 mL to prepare a growth-promoting agent solution (9-oxoODA / 13-oxoODA>1).

[0064] • Soybean growth promoting effect Soybean seeds (variety: Fukuyutaka) were sown at a rate of 4 seeds per pot in 3-inch pots filled with vegetable and flower seed-starting soil (manufactured by Takii Seed Co., Ltd.). The plants were grown for 30 days in an artificial climate chamber (LH-60FL3-DT: manufactured by Nippon Ika Kikai Seisakusho Co., Ltd.) with a daily cycle of 14 hours at 25°C under fluorescent lights and 10 hours at 20°C with the lights off.

[0065] The aforementioned growth-promoting solution (9-oxoODA / 13-oxoODA>1) was sprayed onto the leaves of 20 soybean plants at a rate of 1 mL per plant using a spray bottle 30 days after sowing.

[0066] 24 hours after spraying, 5 samples were taken from each of 2 plants, including the growing point and new leaves. These samples were weighed into 15 mL lidded centrifuge tubes (fresh weight: FW), and immediately transferred to a -80°C freezer for 24 hours.

[0067] A mixture of ethanol, water, and acetic acid (80:20:1) was added to the frozen sample to a concentration of 0.1 g / mL. After crushing the beads, sonication was performed for 10 minutes. This mixture was allowed to stand for 1 hour, and then centrifuged at 3000 rpm for 5 minutes using a himac CT6E centrifuge (manufactured by Eppendorf Himac Technologies, Ltd.). The supernatant was filtered through a membrane filter to obtain the analytical sample.

[0068] The analytical samples were analyzed for glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid using an LC-MS / MS instrument (LC section: DIONEX Ultimate3000, MS / MS section: Q Exactive Focus: Thermo Fisher Scientific K.K.) under the following conditions: Column = Aclaim PR-MS 2.1 mmφ × 150 mm (Thermo Fisher Scientific K.K.), Solvent = 2% acetonitrile / aqueous acetate → 10% acetonitrile / aqueous acetate, Flow rate = 0.25 mL / min, Column temperature = 40°C, Detection = MS-(SIM), Introduction = 2 μL of sample solution. Qualitative analysis was performed using glycine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), sucrose (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 2-hydroxypyridine (manufactured by Tokyo Chemical Industries, Ltd.), and L-pyroglutamic acid (manufactured by Nacalai Tesque Corporation) as standard substances, and quantitative analysis was performed using the peak intensity area of ​​MS-. The results are shown as a graph with relative values, with Comparative Example 1 (an example in which water was applied instead of the growth stimulant solution) set to 1.0. The quantitative results for glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid are shown in Figures 1 to 4, respectively.

[0069] Furthermore, the analytical samples were subjected to plant hormone analysis using an LC-MS / MS instrument under the following conditions: Column = Aclaim PR-MS 2.1 mmφ × 150 mm (Thermo Fisher Scientific Co., Ltd.), Solvent = 2% acetonitrile / acetic acid solution → 95% acetonitrile / acetic acid solution, Flow rate = 0.25 mL / min., Column temperature = 40°C, Detection = MS-(SIM), Introduction = 2 μL of sample solution. For cytokinin, trans-zeatin (Fujifilm Wako Pure Chemical Corporation) was used as a standard, and for gibberellin, gibberellin A1 (Toronto Chemical Corporation) was used. Calibration curves were prepared using the analytical values, and quantification was performed from the peak area value of MS-. The cytokinin content was 4.7 ng / gFW, and the gibberellin content was 3.8 ng / gFW. The quantitative results of cytokinin and gibberellin, shown as a graph with comparative example 1 (an example where water was applied instead of the growth stimulant solution) set to 1.0, are shown in Figures 5 and 6, respectively.

[0070] [Example 2] • Preparation of growth-promoting solution As a raw material containing fatty acids, 580g of 90% pure linoleic acid (manufactured by NOF Corporation) was used. To this, 216g of potassium carbonate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 280g of dipotassium hydrogen phosphate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 13,000mL of distilled water were added to prepare the test solution. The pH of the test solution at this time was 9.0.

[0071] 40 mg of lipoxygenase (Nacalai Tesque Co., Ltd., derived from soybeans) was added to the test solution, and the reaction was carried out at 15°C for 3 hours while aerating with oxygen and stirring. The reaction mixture was then placed in a 90°C water bath for 90 minutes. The resulting reaction solution was designated as Solution A.

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

[0073] The entire contents of solution A and the entire contents of solution B obtained above were mixed, and the resulting mixture was subjected to MS using 13-oxoODA and 9-oxoODA from Cayman Chemicals, and 9,10,13-trihydroxy-11-octadecaenoic acid and 9,12,13-trihydroxy-10-octadecaenoic acid from La Rhodan Fine Chemicals as standard substances. 2 Quantitative analysis was performed using LC-MS with spectral analysis. Additionally, ketooctadecadienoic acid (13-oxoODA, 9-oxoODA) was quantified using the absolute calibration curve method at a detection wavelength of UV 272 nm, and trihydroxyoctadecadienoic acid was quantified using the detection wavelength of UV 210 nm.

[0074] The combined yield of isomers such as (E,E) and (E,Z) was 3.7% for 13-oxoODA. The yield of 9-oxoODA was 1.7%. The combined yield of 9,10,13-trihydroxy-11-octadecaenoic acid and 9,12,13-trihydroxy-10-octadecaenoic acid was 1.2%, and the recovery rate of linoleic acid was 84.1%.

[0075] 0.1 mL of the above mixture (a mixture of solution A and solution B prepared above) was diluted with ion-exchanged water to 2000 mL to prepare a comparative growth stimulant solution (9-oxoODA / 13-oxoODA<1).

[0076] • Soybean growth promoting effect Instead of the growth stimulant solution used in Example 1, a comparative growth stimulant solution was used, and the comparative growth stimulant solution was sprayed onto the soybean leaves in the same manner as in Example 1. Subsequently, the samples were collected, extracted, and the resulting analytical samples were subjected to component analysis, in the same manner as in Example 1.

[0077] The analytical results for glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid are shown as relative values ​​in a graph, with Comparative Example 1 (an example where water was applied instead of the growth stimulant solution) set to 1.0. The quantitative results for glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid are shown in Figures 1 to 4, respectively.

[0078] The cytokinin content was 4.2 ng / gFW, and the gibberellin content was 3.2 ng / gFW. The quantitative results of cytokinin and gibberellin, shown as relative values ​​with Comparative Example 1 (an example where water was applied instead of the growth stimulant solution) set to 1.0, are shown in Figures 5 and 6, respectively.

[0079] [Comparative Example 1] In this experiment, instead of the growth stimulant solution used in Example 1, deionized water was used, and the deionized water was sprayed onto the soybean leaves in the same manner as in Example 1. Subsequently, the samples were collected, extracted, and the resulting analytical samples were subjected to component analysis, in the same manner as in Example 1.

[0080] The analytical results for glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid were set to 1.0, and the analytical results for Examples 1 and 2 were expressed as relative values. The results are shown in Figures 1 to 4.

[0081] The cytokinin content was 4.4 ng / gFW, and the gibberellin content was 3.1 ng / gFW. The results of the analyses for Example 1 and Example 2 are shown as relative values, with each analysis result set to 1.0, as shown in Figures 5 and 6, respectively.

[0082] As shown in Figures 1-4, the content of glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid increased in soybean leaves treated with growth-promoting solutions containing ketooctadecadienoic acid (Examples 1 and 2). From the results of Examples 1 and 2, it can be seen that the levels of glycine, sucrose, 2-hydroxypyridine, and L-pyroglutamic acid in soybean leaves increased more when treated with the growth-promoting solution of Example 1, which contains a large amount of 9-oxoODA (9-oxoODA / 13-oxoODA > 1), compared to when treated with the growth-promoting solution of Example 2, which contains a large amount of 13-oxoODA (9-oxoODA / 13-oxoODA < 1).

[0083] 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, an increase in these four components means an increase in soybean yield. From the results in Figures 1 to 4, it can be seen that applying a growth stimulant solution containing ketooctadecadienoic acid increases soybean yield, but a growth stimulant solution containing a relatively large amount of 9-oxoODA is more effective in increasing soybean yield.

[0084] Furthermore, the results in Figures 5 and 6 show that cytokinin and gibberellin in soybean leaves were increased when a growth stimulant solution containing a relatively high amount of 9-oxoODA was applied compared to when a growth stimulant solution containing a relatively high amount of 13-oxoODA was applied. Cytokinin is a plant hormone that prevents soybean pods from falling off (pod drop prevention effect), and gibberellin is a plant hormone that promotes soybean flower bud formation. The growth stimulant solution of Example 1, which contains a relatively high amount of 9-oxoODA, has the effect of increasing both cytokinin and gibberellin in soybeans, and therefore has the effect of increasing soybean yield.

Claims

1. A plant activator for soybeans comprising at least one compound selected from ketooctadecadienoic acid or its derivatives, structural isomers, or salts thereof.

2. The soybean plant activator according to claim 1, wherein the ketooctadecadienoic 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.

3. The soybean plant activator according to claim 2, comprising at least 9-oxo-10,12-octadecadienoic acid.

4. The plant activator for soybeans according to claim 1, comprising at least two types of ketooctadecadienoic acid.

5. The plant activator for soybeans according to claim 4, comprising 13-oxo-9,11-octadecadienoic acid and 9-oxo-10,12-octadecadienoic acid.

6. The plant activator for soybeans according to claim 5, wherein the ratio of the content of 9-oxo-10,12-octadecadienoic acid to the content of 13-oxo-9,11-octadecadienoic acid is greater than 1 by weight.

7. The plant activator for soybeans according to claim 5, wherein the ratio of the content of 9-oxo-10,12-octadecadienoic acid to the content of 13-oxo-9,11-octadecadienoic acid is greater than 1.5 by weight.

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

9. A plant activator for soybeans according to claim 1, which increases the amount of plant hormones produced.

10. The soybean plant activator according to claim 9, wherein the plant hormone is cytokinin and / or gibberellin.

11. The soybean plant activator according to claim 1, characterized in that the soybean plant activator is for preventing pod drop and / or promoting flower bud formation and / or improving yield.

12. The soybean plant activator according to claim 1, which is used as a spray or dipping agent applied to the stems, leaves, or roots of soybeans, or as a soil drenching agent.

13. The plant activator for soybeans according to claim 1, further comprising a hydroxylated fatty acid or a derivative thereof or a salt thereof.

14. The soybean plant activator according to claim 13, wherein the hydroxylated fatty acid is at least one selected from the group consisting of 9,10,13-trihydroxy-11-octadecaenoic acid and 9,12,13-trihydroxy-10-octadecaenoic acid.

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