Plant growth promoting components

Abstract

To provide a plant growth-promoting composition capable of promoting plant growth more safely and inexpensively than conventional materials. [Solution] A plant growth-promoting composition containing one or more active ingredients selected from the group consisting of onion extract and onion powder.

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 comprises 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, studies have been conducted to date on improving environmental stress tolerance and increasing yield in plants using various materials, but no examples have been reported on the use of onion extract or onion powder. [Means for solving the problem]

[0007] As a result of extensive research, the present inventors have found that, by using a highly accurate screening method that they independently developed, one or more substances selected from the group consisting of onion extract and onion powder can act as active ingredients for promoting plant growth, thereby completing the present invention.

[0008] That is, the present invention is as follows. [1] A plant growth-promoting composition comprising, as an active ingredient, one or more members selected from the group consisting of onion extract and onion powder. [2] The plant growth-promoting composition according to [1] above, which has the effect of promoting phosphate absorption. [3] The plant growth-promoting composition according to [2] above, which increases the expression level of a phosphate absorption-related gene. [4] The plant growth-promoting composition described in [2] above, further having the effect of improving stress tolerance to one or more stresses selected from the group consisting of chemical stresses including nutrient deficiency stress or nutrient excess stress, pH stress, and salt stress. [5] The plant growth-promoting composition according to [4] above, which increases the expression level of stress tolerance genes against one or more stresses selected from the group consisting of chemical stresses including nutrient deficiency stress or nutrient excess stress, pH stress, and salt stress. [6] The plant growth-promoting composition according to any one of [1] to [5] above, which has one or more plant growth-promoting effects selected from the group consisting of increasing the elongation or weight of stems, leaves or roots, increasing the number of leaves, promoting flowering or fruiting, increasing the number of flowers or fruits, increasing plant weight or crop yield, greening, and promoting tillering. [7] 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 onion extract and onion powder to a plant, or to soil or culture solution in which the plant grows. [8] The plant growth-promoting method according to [7] 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 the composition of the present invention containing one or more selected from the group consisting of onion extract and onion powder to plants, plant growth can be promoted more safely and inexpensively than with conventional materials. [Brief explanation of the drawings]

[0010] [Figure 1] These are images showing the improvement in root growth of rice plants when no onion extract was added (left) and when 0.45 mL of a plant growth-promoting composition containing onion extract was added (right) (Example 1). [Figure 2] These are images showing the improvement in root growth of rice plants when no onion extract was added (left) and when 0.90 mL of a plant growth-promoting composition containing onion extract was added (right) (Example 1). [Figure 3]1 shows the results of measuring the dry weight of rice roots when no onion extract was added and when 0.45 mL or 0.90 mL of a plant growth-promoting composition containing onion extract was added (Example 1). [Figure 4] The total amount of phosphorus contained in the roots of rice plants when no onion extract was added and when 0.45 mL or 0.90 mL of a plant growth-promoting composition containing onion extract was added is shown (Example 2). [Figure 5] These are images showing the improvement in root growth of rice plants when no onion powder was added (left) and when 0.45 g of a plant growth-promoting composition containing onion powder was added (right) (Example 3). [Figure 6] These are images showing the improvement in root growth of rice plants when no onion powder was added (left) and when 0.90 g of a plant growth-promoting composition containing onion powder was added (right) (Example 3). [Figure 7] The dry root weight of rice was measured when no onion powder was added and when 0.45 g or 0.90 g of a plant growth-promoting composition containing onion powder was added (Example 3). [Figure 8] The total amount of phosphorus contained in the roots of rice plants is shown when no onion powder is added (left) and when 0.45 g or 0.90 g of a plant growth-promoting composition containing onion powder is added (Example 4). [Figure 9] 1 shows the expression levels of phosphate absorption-related genes in rice roots when no onion extract was added and when 0.90 mL of a plant growth-promoting composition containing onion extract was added (Example 5). 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 onion extract and onion powder. The plant growth-promoting composition of this embodiment may contain one or two active ingredients selected from the group consisting of onion extract and onion powder. That is, the plant growth-promoting composition may contain only one of onion extract or onion powder as the active ingredient, or may contain both onion extract and onion powder as active ingredients. Onions are plants of the genus Allium in the family Amaryllidaceae. Specific examples include Allium cepa. The onion variety is not particularly limited, and examples thereof include yellow onions, white onions, purple onions (red onions), salad onions, salad onions, pearl onions, ruby ​​onions, spring onions, and shallots. More specifically, examples thereof include Kitawasei 3, SN-1, SN-3, SN-3A, Okhotsk 222, Okhotsk 1, Okhotsk 333, Kitamomiji 2000, Super Kitamomiji, H235, and Kitawa Yate No. 2, Bullet Bear, Arrow Bear, Power Wolf, Brown Bear, Kodiak, Ikor, Vegas, Hayajiro, Sarari, Karoe One, Ezomaru, Sarasara Gold, Kurenai, R-5, Red Eye Early, Red Eye II, Red Eye, Red One, Yukigeisha 2, Yukigeisha, White No. 1, Kitawase No. 1, Pekoros 22 Super, Pekoros F Okhotsk, Kitami Yellow, Sapporo Yellow, Sorachi Yellow, Quel Gold, OPP-5 , OMP-3, OSP-3, CS3-12, Toyohira, Idol Momoe, Idol Masako, Idol Junko, Keeper 808, Keltama Ruby, Hero Z, Polestar 100, Shojo Aka, The Fragrance of Spring, Hokkai Tenshin, Northern Rouge, Toyosan Kogane, Toyosan Kurenai, Hitaten, Hitama, Late-season Kogane, Hakata Kogane EX, Hakata Kogane, Tokyo Red, Tenju Onion, Storage Fishing Ball, Medium-season Kogane, Earth Super Up, Earth A Up No. 2, Chikyu Up No. 1, Large Scarlet Ball, Early Taka, Early Maru Hidetama E Type, Early Maru Hidetama, Early Kogane, Senshu Chutaka Yellow, Senshu Chutaka, Red Tama Salad, New Late Kogane, Shonan Red, Harukaze Maru, Haruichiban, Hidetama Maru, Takano Round Onion, Takano Golden Onion, Beni Hidetama Maru, Koko Aka, Koko Rouge, Tsukinowa No. 2, Kei, Gold Award Senshu Yellow No. 2 Onion, Gold Award Shunyo Yellow Onion, Gold Award Tama Spring Onion, Nishikimari, Takanishiki, Improved Unzen Maru, Oshu, Unzen Super Early, Rose Tama, Red Relief,Roubaix, Levain, Lambda No. 2, Lambda Yellow, Lucky, Momiji No. 3, Marumi, Mach, Mercury No. 3, White Bear, Bolt, Hold, Fresh Red, Power, Happy 501, Hyper Linear (Test Crossing MO-75), Neo Earth, Top Gold 525, Top Gold 515, Top Gold 430, Top Gold 415, Top Gold 305, Turbo, Tarzan, Sonic, Century No. 2, Swallow, Spurt, Super Haru Ichiban, Super Linear, Super Moon, Super Kogane, Charm, Shinonome, Jet Boat Examples of varieties include Lu, Jet Star, Salad Red, Sakura Express II, Sakura Express I, Kohaku No. 2, Kohaku, Keru Tama, Kurenai, Aurora, Ei-One, Yellow Drop, Amagashi No. 2, Aton, Early Top, O·P Yellow, O·L Yellow, O·K Yellow, MT-1411, F1 Early-Grown Onion, F1 Very Early-Grown FA Onion, F1 Kyoto-Grown Onion, AS-115, Kazusa No. 13, Tiger Jet, KA953, KAR-003, KA-957, KA-956, TPS-157, Risshun no Kaori, TG-320, Hama no Takara, Hamawarai, and Noncoola. The origin of the onion is also not particularly limited.

[0013] In this embodiment, the onion extract refers to specific components extracted from onions. The parts used for the extraction are not particularly limited, and examples include leaf blades, leaf sheaths (petioles), bulbs (scale leaves, storage leaves, edible parts), skins (protective leaves), cores, stems (flower stalks and flower bulb bolts), and roots, which may be used alone or in combination. The onion extract can be obtained, for example, by the method described in the "Method for preparing a plant growth-promoting composition" below. The onion powder is obtained by drying and pulverizing onions or onion 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 increasing the elongation or weight of stems, leaves, or roots, increasing the number of leaves, promoting flowering or fruiting, increasing the number of flowers or fruits, increasing plant weight or crop yield, greening, or promoting tillering.

[0015] More specifically, a plant growth-promoting effect is observed when the actual weight increase (%) or dry weight increase (%) is increased when the plant growth-promoting composition of the present embodiment is used compared to when it is not used. 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 increase (%) or dry weight increase (%) is preferably increased by 10% or more, more preferably 20%, and even more preferably 30% or more, compared to when the plant growth-promoting composition of the present embodiment is not used. A plant growth-promoting effect includes when no growth is observed without the use of the plant growth-promoting composition, but growth is observed after 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 have a phosphate absorption-promoting effect. In this embodiment, "promoting phosphate absorption" means promoting phosphate absorption by plants, preferably plant roots. Promoting phosphate absorption by plants may increase the amount of phosphate present in the plant. Furthermore, the phosphate whose absorption is promoted may be phosphate in the soil or culture solution in which the plant grows, or phosphate in a fertilizer applied to the soil or culture solution. The plant growth-promoting composition of this embodiment may activate phosphate absorption-related molecules, thereby promoting phosphate absorption by plants. In one embodiment, this embodiment also provides a phosphate absorption-promoting composition containing one or more active ingredients selected from the group consisting of onion extract and onion powder.

[0018] The plant growth-promoting composition of the present embodiment may exhibit a plant growth-promoting effect by having a phosphate absorption-promoting effect.

[0019] The phosphate absorption-promoting effect of the plant growth-promoting composition in this embodiment can be confirmed, for example, by growing a plant to which the plant growth-promoting composition has been applied under conditions of a growth temperature and growth period that are suitable for the plant, and comparing and evaluating the amount of phosphate in the plant (preferably, the roots of the plant) with the amount of phosphate in a plant to which the plant growth-promoting composition has not been applied.

[0020] When the plant growth-promoting composition of the present embodiment has a phosphate absorption-promoting effect, it may further have an effect of imparting tolerance to environmental stresses such as chemical stress, pH stress, salt stress, etc. Chemical stresses include, for example, nutrient deficiency stress and nutrient excess stress.

[0021] In this embodiment, "environmental stress" tolerance refers to a trait that allows a plant to grow normally or in a near-normal state 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 have undesirable effects on the growth of ordinary plants.

[0022] The plant growth-promoting composition in this embodiment may have the effect of promoting phosphate absorption and the effect of improving stress tolerance to one or more stresses selected from the group consisting of chemical stress, including nutrient deficiency stress or nutrient excess stress, pH stress, and salt stress.

[0023] In this embodiment, the environmental stress tolerance of a plant can be confirmed by growing the target plant under each environmental stress condition and evaluating the phenotype. For example, the presence or absence of salt stress tolerance can be confirmed by growing the target plant in a medium or soil to which an appropriate concentration of salt has been added under conditions of a growth temperature and growth period suitable for the plant, and evaluating the phenotype.

[0024] When the plant growth-promoting composition of the present embodiment has a phosphate absorption-promoting effect, it may increase the expression level of a phosphate absorption-related gene. The phosphate absorption-related gene is not particularly limited, and examples thereof include commonly known genes that are thought to be related to phosphate absorption, such as genes disclosed in known databases such as the National Center for Biotechnology Information (NCBI), Ensembl Plants, The Arabidopsis Information Resource (TAIR), and The Rice Annotation Project (RAP).

[0025] When the plant growth-promoting composition of this embodiment has the effect of improving environmental stress tolerance, it may activate a gene in a stress response system. Examples of genes in a stress response system include, but are not limited to, genes generally known as response indicators to chemical stress, pH stress, and salt stress. Genes generally known as response indicators to chemical stress may also be genes generally known as response indicators to nutrient deficiency stress or nutrient excess stress. Genes generally known as response indicators to chemical stress, pH stress, and salt stress are, for example, genes disclosed in known databases such as the National Center for Biotechnology Information (NCBI), Ensembl Plants, The Arabidopsis Information Resource (TAIR), and The Rice Annotation Project (RAP).

[0026] The plant growth-promoting composition of this embodiment may contain one or more selected from the group consisting of onion extract and onion powder, either alone or in combination with one or more agriculturally acceptable ingredients. The agriculturally acceptable ingredients are not particularly limited, but examples thereof include solvents, carriers, excipients, binders, solubilizers, stabilizers, thickeners, leavening agents, lubricants, surfactants, oily liquids, buffers, disinfectants, antifreeze agents, antifoaming agents, colorants, antioxidants, preservatives, and additional active ingredients. Preferred agriculturally acceptable carriers are agriculturally acceptable liquid carriers such as water, mineral oil fractions such as kerosene or diesel oil, oils of vegetable or animal origin, cyclic or aromatic hydrocarbons (e.g., paraffin, tetrahydronaphthalene, alkylated naphthalenes or derivatives thereof, or alkylated benzenes or derivatives thereof), alcohols (e.g., methanol, ethanol, propanol, butanol, or cyclohexanol), ketones (e.g., cyclohexanone), or amines (e.g., N-methylpyrrolidone), or mixtures thereof.

[0027] When the plant growth-promoting composition of this embodiment contains one or more additional active ingredients, various compounds known in the art that have the effect of promoting phosphate absorption and improving environmental stress resistance can be used as the additional active ingredients. When the plant growth-promoting composition contains one or more additional active ingredients, the effect of promoting phosphate absorption and environmental stress resistance of plants tend to be further improved.

[0028] 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, pesticides may be fungicides, insecticides, insecticides, fungicides, miticides, nematicides, rodenticides, insect repellents, attractants, spreaders, hormones (growth regulators), and herbicides. Fertilizers may be organic fertilizers, chemical fertilizers, liquid fertilizers, solid fertilizers, compound fertilizers, compost, growth promoters, stimulants, calcium supplements, and the like. Soil conditioners may be those intended for physical, chemical, or biological soil improvement, and may also be oxygen suppliers, etc. Furthermore, pesticides, fertilizers, soil conditioners, and potting soil may contain components derived from plants, animals, lime, ores, or microorganisms.

[0029] The content of one or more ingredients selected from the group consisting of onion extract and onion 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 ingredients selected from the group consisting of onion extract and onion powder function as active ingredients for promoting plant growth. For example, the content may be 5, 10, 20, 30, 40, 50, 60, 70, 80, or 90% by mass (volume %) or more, and may be 99, 95, 90, 80, 70, 60, 50, 40, 30, 20, or 10% by mass (volume %) or less.

[0030] 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 when applied.

[0031] 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.

[0032] 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.

[0033] The target plant may be not only the whole plant (i.e., the complete plant), 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.

[0034] 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).

[0035] <Method for preparing plant growth-promoting composition> The plant growth-promoting composition can be prepared, for example, by obtaining one or more components selected from the group consisting of onion extract and onion powder, and then mixing the components with the above-mentioned agriculturally acceptable components, as needed. The method for obtaining onion extract is not particularly limited, and general methods for extracting plant extracts can be used. Specifically, for example, onion extract can be obtained by a method comprising the steps of: heating or crushing one or more selected from the group consisting of onion leaf blades, leaf sheaths (petioles), bulbs (scale leaves, storage leaves, and edible parts), skins (protective leaves), cores, stems (flower stalks and flower bulb bolts), and roots, followed by removing impurities to obtain an onion extract raw material; concentrating the onion extract raw material obtained in the step to obtain an onion concentrate; and fractionating the onion concentrate obtained in the step to obtain an onion extract containing specific components. Alternatively, the onion extract raw material or the onion concentrate may be used directly as the onion extract. The onion extract raw material, onion concentrate, or onion extract may be heated or pressurized during or after each step. A solvent may be added as appropriate during the heating or pressurizing treatment. The conditions for obtaining the onion extract can be appropriately determined depending on the variety, part, condition, etc. of the onion used. The method for obtaining onion powder is not particularly limited, and the onion powder can be obtained by drying fresh or frozen onion residues such as impurities generated when obtaining an onion extract raw material, an onion concentrate, or an onion extract, an onion extract raw material, an onion concentrate, an onion extract, or onions (one or more selected from the group consisting of onion leaf blade, leaf sheath (petiole), bulb (scale leaves, storage leaves, edible part), skin (protective leaves), core, stem (flower stalk and flower bulb bolt), and root) by a method such as hot air drying, air drying, dry heat drying, or reduced pressure drying, and then crushing the dried onion powder into powder.

[0036] (Crushing process) Onions can be crushed using fresh or dried onions, for example, in a mixer. When crushing onions, an appropriate amount of water may be added to facilitate processing in a mixer or the like. The crushed onions are filtered using a filter cloth, filter paper, or the like to obtain an onion 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.

[0037] (concentration process) The obtained onion extract raw material can be concentrated using a method such as vacuum concentration, freeze concentration, or membrane concentration to obtain an onion 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 handleability and reduce transportation costs because the amount of plant growth-promoting composition added to plants is reduced, 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 preparing the plant growth-promoting composition, it is not essential to concentrate the onion extract raw material, and the obtained onion extract raw material may be subjected to the following fractionation step as is.

[0038] (Fractionation process) The resulting onion concentrate can be fractionated by solvent extraction or other methods to obtain an onion 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.

[0039] The onion extract obtained in the fractionation step may be further subjected to purification treatment or separation treatment of highly active fractions, if necessary. Examples of purification treatments include filtration, adsorption (ion exchange resin column, activated carbon column, etc.), etc. Furthermore, examples of separation treatments of highly active fractions include gel filtration, adsorption, silica gel column chromatography, HPLC, etc.

[0040] <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 the above-mentioned onion extract and onion powder to a plant, or to the soil or culture solution in which the plant is growing. In this method, the plant growth-promoting composition can be applied to a plant or a 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 is growing. Plant growth can be promoted 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 is growing.

[0041] The present embodiment also provides a method for promoting phosphate absorption by plants by applying a composition containing one or more active ingredients selected from the group consisting of the onion extract and onion powder to plants or to the soil or culture solution in which the plants grow.

[0042] 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.

[0043] 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.

[0044] The amount of the 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 or other area 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 a sufficient plant growth-promoting effect tends to be achieved when the plant growth-promoting composition is used in an amount within the above ranges, the amount used may be adjusted appropriately depending on the content of one or more compounds selected from the group consisting of onion extract and onion 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 a concentration range in which an effect can be achieved 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 %.

[0045] 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.

[0046] The preferred range of the amount used varies depending on the concentration rate of the onion extract raw material, but the preferred range of the amount used is a range where the concentration rate is 3 to 30 times. [Example]

[0047] 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.

[0048] (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.

[0049] (Preparation of onion extract) An onion extract raw material was obtained from 100 g of onion bulbs cut at intervals of 1 to 10 mm, and the extract raw material was then concentrated about 5 times to obtain the onion extract used in Examples 1 to 3.

[0050] [Example 1] We evaluated whether onion extract increases root weight, which is important for fertilizer absorption, using rice.

[0051] (seedling growing period) Rice germinated by soaking in distilled water was transferred to a hydroponic culture solution with the seedling-raising concentration shown in Table 1. The seedlings transferred to the culture solution were then transferred to an artificial climate chamber and raised while the hydroponic culture solution was changed. (Exam period) The rice plants grown as described above were transferred to containers containing 900 mL of hydroponic culture solution containing the test-period concentrations shown in Table 1. Three test plots were designed: one in which 0.45 mL or 0.9 mL of onion extract was added to give final concentrations of 0.05% or 0.1% by volume, and one in which no onion extract was added (control). The three test plots were then transferred to an artificial cultivation chamber for cultivation, after which the rice plants were removed, dried, and the roots were collected and weighed. A 29.1% weight increase was observed in the test plot containing 0.05% by volume onion extract compared to the control plot (Figures 1 and 3). A 38.5% weight increase was observed in the test plot containing 0.1% by volume onion extract compared to the control plot (Figures 2 and 3). These results demonstrate that onion extract is effective in increasing root weight.

[0052] [Table 1]

[0053] [Example 2] The effect of the addition of onion extract on phosphate absorption was also evaluated using the rice of Example 1.

[0054] (Pretreatment for phosphate determination) The roots of the rice plants dried in Example 1 were transferred individually to a tube. 5 mL of sulfuric acid and 1 mL of hydrogen peroxide were added to decompose the roots. After overnight reaction, 3 mL of the decomposed material was transferred to a new tube. 1 mL of sulfuric acid and 2 mL of hydrogen peroxide were then added. The solution was heated at 200°C for 30 minutes to completely decompose the plant bodies. (Quantitative determination of phosphate) The digest was diluted 200-fold with ultrapure water. Acidic molybdenum solution and acidic ascorbic acid solution were added to the diluted solution to develop color. The solution was transferred to a 96-well plate, and the absorbance was measured using a plate reader to calculate the concentration. When the total amount of phosphate contained in the roots was compared, a 23.1% weight increase was confirmed in the test group containing 0.05% by volume of onion extract, and a 10.7% weight increase was confirmed in the test group containing 0.1% by volume of onion extract, compared to the control group (Figure 4).These results demonstrate that onion extract has the effect of promoting phosphate absorption from the roots.

[0055] [Example 3] We evaluated whether onion powder increases root weight, which is important for fertilizer absorption, using rice plants.

[0056] (Making onion powder) 100 g of onion bulbs cut at intervals of 1 to 10 mm were dried and crushed to obtain onion powder.

[0057] (seedling growing period) The seedlings were grown in the same manner as in Example 1. (Exam period) The rice plants grown as described above were transferred to containers containing 900 mL of the hydroponic culture solution prepared in the same manner as in Example 1. Three test plots were designed: one in which 0.45 g or 0.9 g of onion powder was added to give a final concentration of 0.05% by mass or 0.1% by mass, and one in which no onion powder was added (control). The three test plots were transferred to an artificial cultivation chamber and cultivated. The rice plants were then removed, dried, and the roots were collected and weighed. A 31.4% weight increase was observed in the test plot containing 0.05% by mass of onion powder compared to the control plot (Figs. 5 and 7). A 26.6% weight increase was observed in the test plot containing 0.1% by mass of onion powder compared to the control plot (Figs. 6 and 7). These results demonstrate that onion powder has the effect of increasing root weight.

[0058] [Example 4] The effect of the addition of onion extract on phosphate absorption was also evaluated using the rice of Example 3.

[0059] (Pretreatment for phosphate determination) Pretreatment was carried out in the same manner as in Example 2. (Quantitative determination of phosphate) Phosphate was quantified in the same manner as in Example 2. As a result, a 23.5% weight increase was confirmed in the test group containing 0.05% by mass of onion powder, and a 7.4% weight increase was confirmed in the test group containing 0.1% by mass of onion powder, compared to the control group (Figure 8). These results demonstrate that onion extract has the effect of promoting phosphate absorption from the roots.

[0060] [Example 5] The rice of Example 1 was also used to evaluate the effect of the onion extract on gene expression in rice.

[0061] (Sample preparation) Total RNA was extracted from the roots of rice plants in the control group of Example 1 and the group to which 0.1% by volume of onion extract had been added.

[0062] (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) Measuring equipment: Agilent 2100 Bioanalyzer <g2939a>(Agilent Technologies), reagent kit: Agilent RNA6000 Nano kit <5067 - 1511> (Agilent Technologies) and analysis software: 2100 expert software <version B.02.07> (Agilent Technologies) were used. After confirming that there were no problems with the quality of the RNA samples, they were used for library preparation. (Library preparation) A library for the NextSeq next-generation sequencer was prepared using the QuantSeq 3'mRNA-Seq Library Prep Kit according to the following steps. 1 Use 100 ng of total RNA 2 cDNA synthesis using oligo(dT) primers 3 Removal of template mRNA 4 Double-stranded cDNA synthesis using random primers 5 14-cycle PCR using indexed adapters 6 Purification using beads

[0063] (Analysis by next-generation sequencer) · Sequence analysis Equipment: NextSeq500 (Illumina) Reagent: NextSeq 500 / 550 High Output Kit v2.5 (75 Cycles) <2002490>6> (Illumina) · Sequence (outline) Sequencing was performed using NextSeq500 according to the following steps. 1 Addition of sequencing reagent 2 Single-base extension reaction 3 Removal of unreacted bases 4 Incorporation of fluorescence signal 5 Removal of protecting group and fluorescence 6 Repeat cycles of 2Cycle…3Cycle… and perform up to 75 cycles

[0064] (Data analysis) Primary data analysis Analysis program: bcl2fastq ver2.20 (Illumina) A fastq file was created from the obtained reads using the program bcl2fastq (Illumina). Secondary 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 group and the onion extract-added group. Tertiary data analysis Genes reported to be involved in phosphate uptake 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.

[0065] Gene expression analysis showed that the expression level of phosphate absorption-related genes in the roots was increased by 3.27 times in the onion extract-added area (Figure 9). The enzyme of this phosphate absorption-related gene has been reported to date as follows, and is therefore thought to contribute to the increased phosphate absorption mentioned above. It is present on the surface of the root and interacts directly with external phosphorus (Reference 1). When the expression level of this gene increases under phosphorus-deficient conditions, the amount of phosphate absorbed increases (Reference 1). This gene and similar genes have been reported to be widely present in wheat, pepper, lettuce, tomato, cacao, and other plants in addition to Arabidopsis and rice (References 2 and 3). From the above, it is thought that onion extract has the effect of promoting phosphate absorption in many plants other than rice by stimulating phosphate absorption-related genes or similar molecules.

[0066] Reference 1: https: / / bmcplantbiol.biomedcentral.com / articles / 10.1186 / s12870-020-2316-7 Reference 2: https: / / onlinelibrary.wiley.com / doi / 10.1111 / plb.12668 Reference 3: https: / / www.arabidopsis.org / locus?key=27574

Claims

1. A phosphate absorption-promoting composition comprising, as an active ingredient, one or more members selected from the group consisting of onion extract and onion powder.

2. The phosphate absorption-promoting composition according to claim 1, which increases the expression level of a phosphate absorption-related gene.

3. The phosphate absorption-promoting composition according to claim 1, which has the effect of improving stress resistance to one or more stresses selected from the group consisting of chemical stresses including nutrient deficiency stress or nutrient excess stress, pH stress, and salt stress.

4. The phosphate absorption-promoting composition according to claim 3, which increases the expression level of stress resistance genes against one or more stresses selected from the group consisting of chemical stresses including nutrient deficiency stress or nutrient excess stress, pH stress, and salt stress.

5. The phosphate absorption-promoting composition according to any one of claims 1 to 4, having one or more plant growth-promoting effects selected from the group consisting of increasing the elongation or weight of stems, leaves or roots, increasing the number of leaves, promoting flowering or fruiting, increasing the number of flowers or fruits, increasing plant weight or crop yield, greening, and promoting tillering.

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

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

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