Plant growth-promoting composition

Abstract

To provide a plant growth-promoting composition that allows safer and more cost-effective promotion of plant growth compared with conventional materials.SOLUTION: A plant growth-promoting composition comprising, as an active ingredient, at least one selected from the group consisting of persimmon extract and persimmon powder.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a plant growth promoting composition and a method for promoting plant growth. [Background technology]

[0002] With the current explosive growth in the human population, producing a sufficient supply of plants for food has become a global challenge. Furthermore, desertification due to the reduction in green space has become a problem, and rising earth temperatures due to global warming have also become a problem, resulting in an increasing number of environmental problems affecting plant growth. In other words, excessive stress on plants caused by global environmental factors often causes problems for plant growth.

[0003] Therefore, there is a demand for technologies that promise more efficient harvesting than conventional technologies, and biostimulants are attracting attention as a new technology that reduces damage to plants caused by climate and soil conditions by controlling environmental stress on plants, thereby providing healthy plants.

[0004] Patent Document 1 discloses a plant stomatal opening promoter containing stevia, and reports that artificially promoting the opening of plant stomatal pores with stevia improves heat stress resistance. Patent Document 2 discloses a composition for activating genes that activate the ethylene and / or jasmonic acid signaling system, which contains a yeast cell wall decomposition product, and reports that applying the yeast cell wall decomposition product to plants activates the expression of plant defensin genes that are involved in the antibacterial properties and disease prevention of the plant body. Patent Document 3 discloses a method for increasing the yield of grains by inoculating a cell wall-containing substance of a methanol-utilizing bacterium into a plant for cultivating grains. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6741262 [Patent Document 2] Patent No. 4931388 [Patent Document 3] Patent Publication No. 2019-180361 Summary of the Invention [Problem to be solved by the invention]

[0006] As mentioned above, research has been conducted on improving environmental stress tolerance and increasing yields in plants using various materials, but no examples have been reported using persimmon extract or persimmon powder. [Means for solving the problem]

[0007] After extensive research, the inventors discovered that, by using a highly accurate screening method they developed themselves, persimmon extract or persimmon powder, among various materials, is an effective ingredient for promoting plant growth, and thus completed the present invention.

[0008] That is, the present invention is as follows. [1] A plant growth promoting composition comprising one or more active ingredients selected from the group consisting of persimmon extract and persimmon powder. [2] The plant growth-promoting composition described in [1] above has one or more plant growth-promoting effects selected from the group consisting of elongation of stems, leaves or roots, increased leaf number, promotion of flowering or fruiting, increased number of flowers or fruits, increased plant weight or crop yield, greening, and promotion of tillering. [3] The plant growth-promoting composition according to [1] or [2] above, which has the effect of improving environmental stress tolerance. [4] The plant growth-promoting composition described in [3] above has the effect of improving environmental stress tolerance against one or more stresses selected from the group consisting of temperature stress, nutritional stress, chemical stress, light stress, drought stress, pH stress, salt stress, hypoxic stress, herbicide stress, physical stress, and disease stress. [5] The plant growth-promoting composition according to [3] above, which activates genes in the stress response system. [6] A method for promoting plant growth, comprising applying a plant growth-promoting composition containing one or more active ingredients selected from the group consisting of persimmon extract and persimmon powder to a plant or to soil or culture solution in which the plant grows. [7] The plant growth-promoting method according to [6] above, wherein the amount of the plant growth-promoting composition used is 0.001 to 50% by mass or 0.001 to 50% by volume relative to the culture solution or dilution solvent. [Effects of the Invention]

[0009] By applying a composition containing one or more selected from the group consisting of persimmon extract and persimmon powder of the present invention to plants, plant growth can be promoted more safely and inexpensively than with conventional materials. [Brief explanation of the drawings]

[0010] [Figure 1] These images show the improvement in root growth of rice plants when no persimmon extract or persimmon powder was added (left) and when 4.5 mL of a plant growth-promoting composition containing persimmon extract (Example 1) was added (right). [Figure 2] This is a graph showing the root weight of rice plants when no persimmon extract or persimmon powder was added and when 4.5 mL of a plant growth-promoting composition containing persimmon extract was added. [Figure 3] This is an image showing a heat map of the expression levels of high temperature stress resistance genes in rice when no persimmon extract or persimmon powder was added and when 4.5 mL of a plant growth-promoting composition containing persimmon extract was added. [Figure 4]10 is an image showing the expression level of the rice high temperature stress tolerance gene Os05g0110100 when no persimmon extract or persimmon powder was added and when 4.5 mL of a plant growth-promoting composition containing persimmon extract was added. [Figure 5] This is an image showing a heat map of the expression levels of drought stress tolerance genes in rice when no persimmon extract or persimmon powder was added and when 4.5 mL of a plant growth-promoting composition containing persimmon extract was added. [Figure 6] 10 is an image showing the expression level of the rice drought stress tolerance gene Os03g0225100 when no persimmon extract or persimmon powder was added and when 4.5 mL of a plant growth-promoting composition containing persimmon extract was added. [Figure 7] This is an image showing a heat map of the expression levels of salt stress tolerance genes in rice when no persimmon extract or persimmon powder was added and when 4.5 mL of a plant growth-promoting composition containing persimmon extract was added. [Figure 8] 10 is an image showing the expression level of the rice salt stress tolerance gene Os01g0200700 when no persimmon extract or persimmon powder was added and when 4.5 mL of a plant growth-promoting composition containing persimmon extract was added. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, a mode for carrying out the present invention (hereinafter also referred to as "the present embodiment") will be described in detail. Note that the present invention is not limited to the present embodiment, and various modifications can be made within the scope of the gist of the present invention.

[0012] <Plant growth promoting composition> The plant growth-promoting composition of this embodiment contains one or more active ingredients selected from the group consisting of persimmon extract and persimmon powder. Persimmon (Diospyros kaki) is a plant of the genus Diospyros in the family Ebenaceae. Specific examples include Diospyros lotus, and more specifically Diospyros melanoxylon. The variety and origin of persimmon are not particularly limited, and examples include Ichida persimmon, Fuyu persimmon, and Gosho persimmon.

[0013] In this embodiment, the persimmon extract is obtained by extracting specific components from various parts of a persimmon, and is not particularly limited. The persimmon extract can be obtained, for example, by the method described in the "Method for Preparing a Plant Growth-Promoting Composition" below. Furthermore, the persimmon powder is obtained by drying and pulverizing various parts of a persimmon or persimmon extract, and is not particularly limited.

[0014] The plant growth-promoting composition in this embodiment is a composition that has a plant growth-promoting effect, and here, the plant growth-promoting effect includes, for example, growth-promoting effects such as elongation of stems, leaves, or roots, an increase in the number of leaves, promotion of flowering or fruiting, an increase in the number of flowers or fruits, an increase in plant weight or crop yield, greening, or promotion of tillering.

[0015] More specifically, a case where a plant growth-promoting effect is observed refers to, for example, an increase in actual weight gain (%) or dry weight gain (%) when comparing the use of the plant growth-promoting composition of the present embodiment with the use of the composition without the use of the composition. The actual weight or dry weight may be the actual weight or dry weight of the entire plant, or the actual weight or dry weight of each part of the plant (preferably the roots). When the plant growth-promoting composition is used, the actual weight gain (%) or dry weight gain (%) is preferably increased by 10% or more, more preferably 20%, and even more preferably 30% or more compared to the case where the plant growth-promoting composition of the present embodiment is not used. A plant growth-promoting effect includes a case where no growth is observed without the use of the plant growth-promoting composition, but growth is observed after the use of the plant growth-promoting composition. Note that the above values ​​are average values ​​for the entire plant to which the plant growth-promoting composition is applied.

[0016] In addition, the plant growth promoting effect also includes the effect of improving the activity of plants as follows. 1) Root elongation and improved root establishment 2) Increased efficiency of nutrient absorption 3) Induction of flower buds, promotion of flowering, and increase in fruit production 4) Accumulation of sugar and other substances 5) Increased water-saving effect 6) Callus induction effect 7) Increase in plant size, especially elongation or thickening of above-ground and underground parts 8) Wound repair That is, the plant growth-promoting composition of the present embodiment may have the above-mentioned actions 1) to 8) in addition to growth-promoting effects such as elongation of stems, leaves, or roots, increased leaf number, promotion of flowering or fruiting, increased number of flowers or fruits, increased plant weight or crop yield, greening, or promotion of tillering. By exerting the above-mentioned action 1), nutrient absorption by roots may be promoted, and the growth of the entire plant may be promoted.

[0017] The plant growth-promoting composition of this embodiment may confer tolerance to a variety of environmental stresses to which a plant is exposed. The plant growth-promoting composition of this embodiment may have the effect of improving tolerance to environmental stress. Here, examples of environmental stress include biotic stress and abiotic stress, and specific examples include herbicide stress, disease stress, temperature stress such as high temperature stress and low temperature stress, nutritional stress, chemical stress, light stress, drought stress, pH stress such as oxidative stress, salt stress such as osmotic stress, hypoxic stress, and physical stress. Nutritional stress includes, for example, nutrient deficiency stress and nutrient excess stress.

[0018] In this embodiment, "environmental stress tolerance" refers to a trait that allows a plant to grow normally or nearly normally, even under growth conditions that cause environmental stress, without substantially suffering from undesirable effects such as inability to grow (withering), poor growth (e.g., bleaching or yellowing of the plant, reduced root length or reduced leaf number), reduced growth rate, or reduced plant weight or crop yield. By improving the plant's environmental stress tolerance with the plant growth-promoting composition of this embodiment, the plant can grow normally even in external environments that cause undesirable effects on the growth of ordinary plants.

[0019] The temperature stress tolerance-imparting effect of the plant growth-promoting composition of this embodiment includes, for example, the effect of promoting normal growth under high-temperature and low-temperature conditions. High-temperature conditions may be appropriately determined by those skilled in the art based on common general knowledge in the technical field, but are preferably 35°C or higher, for example, 35°C to 50°C. Low-temperature conditions may be appropriately determined by those skilled in the art based on common general knowledge in the technical field, but are preferably 10°C or lower, for example, 0°C to 10°C. Furthermore, the salt stress-imparting effect allows normal growth in the presence of 0.1 to 3.0% by mass of sodium chloride. The drought stress-imparting effect allows normal growth even at a relative humidity of 10 to 40%. The effect of the plant growth-promoting composition of this embodiment in imparting nutritional stress tolerance is, for example, the effect of promoting normal growth in plants that are deficient in chemical substances that serve as nutrient sources for the plant (nutrient-deficient state). Here, the nutrient-deficient state may be, for example, a state in which the amount of each nutrient is less than the amount indicated by the concentration during the test period in Table 1 of the Examples. Specifically, the amount of each nutrient may be approximately one-half to one-third, one-third to one-quarter, one-quarter to one-fifth, one-fifth to one-sixth, one-sixth to one-seventh, or one-seventh to one-eighth of the amount indicated by the concentration during the test period in Table 1. The concentrations during the test period in Table 1 are concentrations commonly used in the cultivation of crops such as rice.

[0020] In this embodiment, the environmental stress tolerance of a plant can be evaluated, for example, by the following means. The presence or absence of salt stress tolerance can be confirmed by growing a target plant in a medium or soil containing an appropriate concentration of salt under conditions of a growth temperature and growth period suitable for the plant, and evaluating the phenotype. The presence or absence of drought stress tolerance can be confirmed by growing a target plant under conditions of a growth temperature, growth humidity, and growth period suitable for the plant, and evaluating the phenotype. The presence or absence of high temperature stress tolerance can be confirmed by acclimating a target plant to a high temperature, such as 35°C to 50°C, and then growing it under conditions of a growth temperature and growth period suitable for the plant, and evaluating the phenotype. Furthermore, the presence or absence of low temperature stress tolerance can be confirmed by acclimating a target plant to a low temperature that does not cause freezing, and then growing it under conditions of a growth temperature and growth period suitable for the plant, and evaluating the phenotype.

[0021] When the plant growth-promoting composition of the present embodiment has an effect of improving environmental stress tolerance, it may activate a gene in a stress response system. Examples of the gene in a stress response system include, but are not limited to, genes generally known as indicators of response to environmental stresses such as temperature stress, nutritional stress, chemical stress, light stress, drought stress, pH stress, salt stress, hypoxic stress, herbicide stress, physical stress, and disease stress. Genes generally known as indicators of response to environmental stress are genes disclosed in publicly known databases such as the National Center for Biotechnology Information (NCBI), Ensembl Plants, The Arabidopsis Information Resource (TAIR), The Rice Annotation Project (RAP), etc. Specifically, genes generally known as indicators of response to high temperature stress include Os01g0135900, Os01g0273500, Os01g0875700, Os02g0753800, Os03g0161900, Os03g0266300, Os03g0426900, Os05g0110100, and Os05g03645 00, Os05g0460000, Os05g0530400, Os06g0682900, Os06g0716700, Os06g0727200, Os08g0127600, Os08g0191100, Os08g0500700, Os09g0133600, Os11g0216100, Os11g0661200, etc. For example, by applying the plant growth-promoting composition of this embodiment to a plant, the following compounds can be effectively inhibited in the plant acclimatized to high temperatures: Os01g0135900, Os01g0273500, Os01g0875700, Os02g0753800, Os03g0161900, Os03g0266300, Os03g0426900, Os05g0110100, Os05g0364500, O The expression levels of genes such as s05g0460000, Os05g0530400, Os06g0682900, Os06g0716700, Os06g0727200, Os08g0127600, Os08g0191100, Os08g0500700, Os09g0133600, Os11g0216100, and Os11g0661200 are increased compared to the control.

[0022] In addition, genes generally known as indicators of response to drought stress include Os01g0615050, Os01g0864500, Os02g0115700, Os02g0178800, Os02g0682300, Os02g0753800, Os02g0766700, Os03g0225100, and Os03g059440. 0, Os05g0127200, Os05g0247100, Os05g0382900, Os05g0542500, Os07g0684000, Os08g0492500, Os09g0271100, Os09g0421700, Os10g0562900, Os11g0167800, Os11g0704500, etc. For example, by applying the plant growth-promoting composition of this embodiment to a plant, the following compounds can be used to promote the growth of plants grown under dry conditions: Os01g0615050, Os01g0864500, Os02g0115700, Os02g0178800, Os02g0682300, Os02g0753800, Os02g0766700, Os03g0225100, Os03g0594400 The expression levels of genes such as Os05g0127200, Os05g0247100, Os05g0382900, Os05g0542500, Os07g0684000, Os08g0492500, Os09g0271100, Os09g0421700, Os10g0562900, Os11g0167800, and Os11g0704500 are increased compared to the control.

[0023] In addition, genes generally known as indicators of response to salt stress include Os01g0141000, Os01g0200700, Os01g0615100, Os01g0624500, Os01g0864500, Os02g0132300, Os02g0327000, Os02g0594700, and Os03g0285700. , Os03g0364400, Os03g0594400, Os03g0678800, Os04g0493000, Os04g0511200, Os04g0530900, Os05g0127200, Os05g0542500, Os07g0684000, Os08g0492500, Os10g0370500, etc. For example, by applying the plant growth-promoting composition of this embodiment to a plant, the following compounds can be grown in a medium or soil containing salt at an appropriate concentration: Os01g0141000, Os01g0200700, Os01g0615100, Os01g0624500, Os01g0864500, Os02g0132300, Os02g0327000, Os02g0594700, Os03g The expression levels of genes such as Os0285700, Os03g0364400, Os03g0594400, Os03g0678800, Os04g0493000, Os04g0511200, Os04g0530900, Os05g0127200, Os05g0542500, Os07g0684000, Os08g0492500, and Os10g0370500 are increased compared to the control.

[0024] The plant growth-promoting composition of this embodiment may contain one or more selected from the group consisting of persimmon extract and persimmon powder, either alone or in combination with one or more agriculturally acceptable ingredients. Agriculturally acceptable ingredients include, but are not limited to, solvents, carriers, excipients, binders, solubilizers, stabilizers, thickeners, leavening agents, lubricants, surfactants, oily liquids, buffers, disinfectants, antifreeze agents, antifoaming agents, colorants, antioxidants, and additional active ingredients. Agriculturally acceptable carriers are preferably agriculturally acceptable liquid carriers such as water, mineral oil fractions such as kerosene or diesel, vegetable or animal oils, cyclic or aromatic hydrocarbons (e.g., paraffin, tetrahydronaphthalene, alkylated naphthalenes or their derivatives, or alkylated benzenes or their derivatives), alcohols (e.g., methanol, ethanol, propanol, butanol, or cyclohexanol), ketones (e.g., cyclohexanone), amines (e.g., N-methylpyrrolidone), or mixtures thereof.

[0025] When the plant growth-promoting composition of this embodiment contains one or more additional active ingredients, various compounds known in the art that have an activity of improving environmental stress tolerance can be used as the additional active ingredients. When the plant growth-promoting composition contains such one or more additional active ingredients, the environmental stress tolerance of the plant tends to be further improved.

[0026] The plant growth-promoting composition of this embodiment can be used in combination with conventional agricultural materials such as pesticides and fertilizers. Examples of agricultural materials include pesticides, fertilizers, soil conditioners, and potting soil (culture soil). Specifically, the pesticides may be fungicides, insecticides, insecticides, fungicides, miticides, nematicides, rodenticides, insect repellents, attractants, spreaders, hormones (growth regulators), herbicides, and the like. The fertilizers may be organic fertilizers, chemical fertilizers, liquid fertilizers, solid fertilizers, compound fertilizers, compost, growth promoters, stimulants, calcium supplements, and the like. The soil conditioners may be those intended for physical, chemical, or biological soil improvement, and may also be oxygen suppliers, and the like. Furthermore, the pesticides, fertilizers, soil conditioners, and potting soil may contain components derived from plants, animals, lime, ores, or microorganisms.

[0027] The content of one or more selected from the group consisting of persimmon extract and persimmon powder in the plant growth-promoting composition relative to the entire plant growth-promoting composition may be any value as long as the one or more selected from the group consisting of persimmon extract and persimmon powder functions as an active ingredient for promoting plant growth, but may be, for example, 5, 10, 20, 30, 40, 50, 60, 70, 80, or 90% by mass (volume %) or more, and 99, 95, 90, 80, 70, 60, 50, 40, 30, 20, or 10% by mass (volume %) or less.

[0028] The plant growth-promoting composition of this embodiment can be used as an agricultural chemical formulation or pesticide to promote plant growth. The plant growth-promoting composition may be in any form, such as a solid (e.g., powder or granules) or a liquid (e.g., a solution or suspension), and is preferably used in the form of a liquid such as a solution or suspension. When used as a solution, it may be in a liquid state, or may be used as a liquid prepared just before use.

[0029] The formulation of the plant growth-promoting composition of this embodiment is not particularly limited, and can be formulated into formulations commonly used in the art, such as emulsions, wettable powders, liquids, water-soluble powders, dusts, powders, pastes, or granules.

[0030] In this embodiment, the plant to which the plant growth-promoting composition is applied is not particularly limited, and examples thereof include angiosperms and gymnosperms. Examples of target plants include Asteraceae plants such as chrysanthemums and gerberas, Solanaceae plants such as potatoes, tomatoes, and eggplants, Brassicaceae plants such as rapeseed and rapeseed, Poaceae plants such as rice, corn, wheat, sugarcane, and barley, Legumes such as soybeans, Apiaceae plants such as carrots, Lamiaceae plants such as basil, mint, and rosemary, Convolvulaceae plants such as morning glory, Salicaceae plants such as poplars, and Euphorbiaceae plants such as castor beans, cassava, and jatropha. Convolvulaceae plants such as sweet potato, Rutaceae plants such as oranges and lemons, Rosaceae plants such as cherry blossoms and roses, Orchidaceae plants such as moth orchids, Gentianaceae plants such as bellflowers, Primulaces such as cyclamen, Violets such as pansies, Liliaceae plants such as lilies, Amaranthaceae plants such as sugar beets, Vitaceae plants such as grapes, Cupressaceae plants such as cedars and cypresses, Oleaceae plants such as olives and Osmanthus, and Pinaceae plants such as red pine.

[0031] The target plant may be not only the whole plant (i.e., the complete plant body), but also parts of the plant such as plant tissues or organs (e.g., cut flowers, or vegetative propagation organs such as rhizomes, tubers, corms, or runners), cultured cells, and / or callus.

[0032] The plant growth-promoting composition of this embodiment can be applied to the whole or part of a plant at any stage of growth, including before or after plant emergence (e.g., the whole or part of a seed, seedling, or mature plant).

[0033] <Method for preparing plant growth-promoting composition> The plant growth-promoting composition can be prepared, for example, by obtaining one or more selected from the group consisting of persimmon extract and persimmon powder, and then mixing it with the agriculturally acceptable ingredients described above as necessary. The method for obtaining persimmon extract is not particularly limited, and general methods for extracting plant extracts can be used. Specifically, persimmon extract can be obtained by a method comprising the steps of heating or crushing persimmon fruit, pulp, skin, stem, branch, or root, and then removing impurities to obtain a persimmon extract raw material; concentrating the persimmon extract raw material obtained in the previous step to obtain a persimmon concentrate; and fractionating the persimmon concentrate obtained in the previous step to obtain a persimmon extract containing specific components. Persimmon extract can also be obtained from one or more persimmon fruit, pulp, skin, stem, branch, or root that have undergone each of the steps for obtaining persimmon extract. For example, persimmon extract raw material or persimmon concentrate can be obtained from persimmon residue, such as impurities removed in the persimmon extract raw material obtaining step, using a method similar to that described above, and then persimmon extract can be obtained from the persimmon extract raw material or persimmon concentrate using a method similar to that described above. Alternatively, persimmon extract can be obtained from persimmon residue, such as impurities obtained during the production of any persimmon processed product. The persimmon extract raw material or persimmon concentrate can be used directly as persimmon extract. In each step or after each step, the persimmon extract raw material, persimmon concentrate, or persimmon extract may be heated or pressurized. When heating, the heating conditions such as heating temperature and heating time can be appropriately determined depending on the variety, part, condition, etc. of the persimmon used. There are no particular limitations on the method for obtaining persimmon powder, and it can be obtained by drying persimmon residue such as persimmon extract raw material, persimmon concentrate, or impurities that are generated when obtaining persimmon extract, fresh or frozen persimmon extract raw material, persimmon concentrate, persimmon extract, or persimmon (one or more selected from the group consisting of persimmon fruit, pulp, skin, stem, branch, or root) using methods such as hot air drying, air drying, dry heat drying, or vacuum drying, and then crushing it into powder.

[0034] (Crushing process) Persimmons can be crushed using fresh or dried persimmons, for example, in a mixer. The crushed persimmons are filtered using filter cloth or filter paper to obtain a persimmon extract raw material from which impurities have been removed. When filtering, an extraction solvent such as an organic solvent may be added beforehand. Alternatively, impurities may be removed by collecting the supernatant using a centrifuge instead of filtration.

[0035] (concentration process) The resulting persimmon extract raw material can be concentrated using vacuum concentration, freeze concentration, membrane concentration, or other methods to obtain a persimmon concentrate. The concentration ratio is preferably 3 to 30 times, and more preferably 4 to 20 times. A concentration ratio of 5 times or more tends to improve handling and reduce transportation costs because less plant growth-promoting composition is added to plants, while a concentration ratio of 30 times or less tends to reduce sediment in the plant growth-promoting composition, making it easier to handle. In addition, in preparing the plant growth-promoting composition, it is not necessary to concentrate the persimmon extract raw material, and the obtained persimmon extract raw material may be subjected to the following fractionation step as is.

[0036] (Fractionation process) The resulting persimmon concentrate can be fractionated by solvent extraction or other methods to obtain persimmon extract containing specific components. In the fractionation process, for example, hydrophilic and hydrophobic fractions can be obtained by liquid-liquid partitioning. Further, more purified fractions can be obtained by passing the fraction through a column.

[0037] The persimmon extract obtained in the fractionation step may be further purified or subjected to separation of highly active fractions, if necessary. Examples of purification include filtration and adsorption (ion exchange resin column, activated carbon column, etc.). Examples of separation of highly active fractions include gel filtration, adsorption, silica gel column chromatography, HPLC, etc.

[0038] <Plant growth promotion method> The plant growth-promoting method of this embodiment is a method for promoting plant growth by applying a composition containing one or more active ingredients selected from the group consisting of persimmon extract and persimmon powder to a plant, or to the soil or culture solution in which the plant grows. In this method, the plant growth-promoting composition can be applied to a plant or part thereof (e.g., a seed, a seedling, or a mature plant) at any growth stage, including before or after germination. Furthermore, the composition can be applied not only to the plant itself, but also to the soil, culture medium, or culture solution in which the plant grows. By applying the plant growth-promoting composition to a plant at any growth stage, or to the soil, culture medium, or culture solution in which the plant grows, plant growth can be promoted.

[0039] The plant growth-promoting composition may be applied to a plant once or multiple times. Furthermore, when the plant growth-promoting composition is applied at multiple application periods, the plant growth-promoting composition may be applied once or multiple times at each application period.

[0040] Examples of means for applying the plant growth-promoting composition to plants include addition, spraying, coating, and immersion. These may be performed alone or in combination of two or more. The plant growth-promoting composition may be applied to plants manually or by machine. When using a machine, there are no particular limitations, but it may be applied (sprayed) by, for example, a drone.

[0041] The amount of plant growth-promoting composition applied to plants, whether applied to a culture solution in which plants grow or diluted with a diluent and applied to a field where plants grow, is preferably 0.001 to 50% by mass or 0.001 to 50% by volume, more preferably 0.01 to 30% by mass or 0.01 to 30% by volume, and even more preferably 0.01 to 10% by mass or 0.01 to 10% by volume. While sufficient plant growth-promoting effects tend to be achieved when the plant growth-promoting composition is used within the above ranges, the amount used may be adjusted appropriately depending on the content of one or more selected from the group consisting of persimmon extract and persimmon powder in the plant growth-promoting composition, the type and growth condition of the plant to which the plant growth-promoting composition is applied, and the plant's growth environment, such as temperature, humidity, and light. The amount used may be determined by investigating the concentration range in which an effect is obtained using a known cultivation test method. When a plant growth-promoting composition diluted with a diluting solvent is applied to a plant using a drone, the amount of solution that can be carried on the drone is limited by the drone's carrying capacity, etc., so the amount of plant growth-promoting composition used relative to the diluting solvent is preferably 1 to 50 mass % or 1 to 50 volume %.

[0042] The components of the culture medium and dilution solvent are not particularly limited as long as they do not adversely affect the growth of the plant, and may contain water, pesticides, etc.

[0043] The preferred range of the amount used varies depending on the concentration of the persimmon extract raw material, but the preferred range is when the concentration is 3 to 30 times. [Example]

[0044] The present invention will be explained in more detail using examples and comparative examples, but the present invention is not limited to these examples in any way.

[0045] (Method for measuring root weight) The roots were identified from the color and shape of the rice plants, and the weight of the identified roots was measured in a bottle using a microbalance.

[0046] [Example 1] 40g of persimmons were peeled, cut, and crushed in ultrapure water. The supernatant was removed from the persimmon extract material obtained after removing impurities, and then an equal volume of ultrapure water was added to the supernatant and resuspended to obtain persimmon extract. Rice was grown in the seedling culture solution shown in Table 1. The rice was then transferred to 900 mL of the test culture solution shown in Table 1, and 4.5 mL (0.5% by volume) of the obtained persimmon extract was added to investigate the effect on the rice. As a result, the weight of the rice roots increased by 15.5% compared to when persimmon extract was not added, demonstrating an effect of improving the root establishment of rice. Furthermore, the concentration of nutrients during the seedling stage was approximately one-sixth to one-seventh of the concentration during the test period, which is sufficient for rice growth, so the rice plants to which persimmon extract had been added were in a state of nutritional deficiency.

[0047] [Table 1]

[0048] [Example 2] Variation in gene expression in rice was also assessed.

[0049] (A) Sample preparation Preparation of rice plants Rice seedlings grown in the same manner as in Example 1 were transferred to 900 mL of culture medium for the test period shown in Table 1, and 4.5 mL (0.5% by volume) of the persimmon extract used in Example 1 was added to the 900 mL of culture medium, and the rice was cultivated. RNA extraction RNA samples were obtained using the Maxwell RSC Plant RNA Kit (Promega) and the Maxwell RSC Instrument (Promega) according to the manufacturer's instructions. RNA quality check Measurement equipment: Agilent 5400 Bioanalyzer <5312AA> (Agilent Technologies), Reagent kit: Agilent RNA kit (15nt) <dnf-471>(Agilent Technologies) and analysis software: ProSize (Agilent Technologies) were used to confirm that there were no problems with the quality of the RNA samples, before they were used for library preparation. Library preparation A library for the next-generation sequencer DNBSEQ T7 was prepared using the NEBNext Ultra II RNA Library Prep Kit for Illumina according to the following steps. 1. Purification of mRNA using oligo(dT) magnetic beads 2 Fragmentation 3. Synthesis of single-stranded and double-stranded cDNA using random primers 4 End repair, polyadenylation, adapter ligation, size selection, and amplification are performed

[0050] (B) Analysis by next-generation sequencer Sequence analysis Equipment: DNBSEQ T7 (MGI) Sequence (outline) Sequencing was performed using DNBSEQ T7 according to the following steps. 1. Addition of Sequencing Reagents 2. Single-base extension reaction 3. Removal of unreacted base 4. Fluorescent signal acquisition 5. Removal of protecting groups and fluorescence 6 Repeat the cycle 2 cycles...3 cycles... until you reach 300 cycles. (C) Data analysis Primary data analysis Analysis computer OS: Ubuntu Desktop 22.04.4 LTS Analysis software: FastQC, hisat2, samtools, HTSeq, DESeq2 The analysis was performed using the software mentioned above. 1. Check the quality of your leads FastQC was used to check the quality of the bases contained in the resulting fastq files. 2 Mapping and Sorting The data were mapped to the Oryza sativa reference genome, Oryza sativa Japonica Group (assembly IRGSP-1.0), using hisat2. The files were then sorted and converted to binary data using samtools. 3 Lead Count The number of mapped reads was counted using htseq-count in HTSeq. 4 Statistical analysis The DESeq2 package in the statistical package R was used to compare gene expression levels between the control and persimmon extract-added areas. Tertiary data analysis Genes reported to be involved in various environmental stress tolerances in previous studies were searched from the Rice Annotation Project (https: / / rapdb.dna.affrc.go.jp / ). The searched genes were then searched from the gene expression list created in this experiment. Selection of target genes and plotting gene expression levels Various environmental stress tolerance genes present in known databases were collected. Various stress tolerance genes were then extracted from the list of genes with elevated expression levels, and their expression levels were displayed as heat maps and bar graphs. In the heat maps in Figures 3, 5, and 7, CTS indicates the control group, and KKS indicates the persimmon extract-treated group.

[0051] Gene expression analysis showed that the expression levels of several heat stress tolerance genes tended to be higher in the shoots of plants treated with persimmon extract than in the control group (Figure 3). In particular, the expression level of the heat stress tolerance gene Os05g0110100 was increased in the shoots (Figure 4). The following findings have been reported regarding these molecules related to heat stress tolerance, and it is thought that they contribute to heat stress tolerance. The expression of molecules homologous to Os05g0110100 is induced by high temperature stress, suggesting that they play an important role in plant survival under high temperature conditions (Reference 1). This gene and similar genes have also been reported to be widely present in Arabidopsis thaliana, rice, and other plants, including rapeseed, wheat, and soybean (Reference 2).

[0052] Gene expression analysis showed that the expression levels of several drought stress tolerance genes tended to be higher in the shoots of the persimmon extract-treated area than in the control area (Figure 5). In particular, the expression level of the drought stress tolerance gene Os03g0225100 increased in the shoots (Figure 6). The following findings have been reported regarding these molecules related to drought stress tolerance, and therefore they are thought to contribute to drought stress tolerance. It has been suggested that the MAP kinase cascade contributes to drought tolerance (Reference 3). This gene and similar genes have been reported to be widely present in plants other than Arabidopsis and rice, such as cotton, soybean, and Physcomitrella patens (Reference 4).

[0053] Gene expression analysis showed that the expression levels of several salt stress tolerance genes tended to be higher in the shoots of plants treated with persimmon extract than in the control group (Figure 7). In particular, the expression level of the salt stress tolerance gene Os01g0200700 increased in the shoots (Figure 8). The following findings have been reported regarding these molecules related to salt stress tolerance, and therefore they are thought to contribute to salt stress tolerance. It has been reported that expressing a homologous gene of Os01g0200700 from a salt-tolerant plant in Arabidopsis increases salt stress tolerance (Reference 5). This gene and similar genes have also been reported to be widely present in Arabidopsis and rice, as well as in wild cotton, soybean, common wheat, and corn (Reference 6).

[0054] From the above, it is thought that persimmon extract can also have the effect of improving tolerance to one or more stresses selected from the group consisting of high temperature stress, drought stress, low temperature stress, and salt stress in many plants other than rice by stimulating high temperature stress tolerance genes, drought stress tolerance genes, salt stress tolerance genes, or similar molecules.

[0055] Reference 1: https: / / pmc.ncbi.nlm.nih.gov / articles / PMC6862505 / #sec4-ijms-20-05321 Reference 2: https: / / www.arabidopsis.org / locus?key=36137 Reference 3: https: / / pubmed.ncbi.nlm.nih.gov / 28857351 / Reference 4: https: / / www.arabidopsis.org / locus?key=29640 Reference 5: https: / / www.nature.com / articles / s41598-017-18263-4 Reference 6: https: / / www.arabidopsis.org / locus?key=135469

Claims

1. A plant growth promoting composition comprising, as an active ingredient, one or more selected from the group consisting of persimmon extract and persimmon powder.

2. The plant growth-promoting composition according to claim 1, which has one or more plant growth-promoting effects selected from the group consisting of elongation of stems, leaves or roots, increased leaf number, promotion of flowering or fruiting, increased number of flowers or fruits, increased plant weight or crop yield, greening, and promotion of tillering.

3. The plant growth-promoting composition according to claim 1 or 2, which has an effect of improving environmental stress tolerance.

4. The plant growth-promoting composition according to claim 3, which has the effect of improving environmental stress tolerance against one or more stresses selected from the group consisting of temperature stress, chemical stress, light stress, drought stress, pH stress, salt stress, hypoxic stress, herbicide stress, physical stress, and disease stress.

5. The plant growth-promoting composition according to claim 3, which activates a gene in a stress response system.

6. A method for promoting plant growth, comprising applying a plant growth-promoting composition containing one or more active ingredients selected from the group consisting of persimmon extract and persimmon powder to a plant or to soil or culture solution in which the plant grows.

7. The plant growth promoting method according to claim 6, wherein the amount of the plant growth promoting composition used is 0.001 to 50% by mass or 0.001 to 50% by volume relative to the culture solution or dilution solvent.

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