Plant environmental stress alleviator, plant growth promoter, and method of using the same

Abstract

To provide novel plant environmental stress alleviator and plant growth promoter having an excellent effect of reducing environmental stress such as high temperatures.SOLUTION: Provided is a plant environmental stress alleviator or a plant growth promoter, which contains a plant extract containing acetylcholine or an acetylcholinesterase inhibitor and calcium ions. Also provided is a method for alleviating plant environmental stress or a method for promoting plant growth by applying the plant environmental stress alleviator or the plant growth promoter to a plant.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to an environmental stress alleviator for plants, a plant growth promoter, and a method for using the same. [Background technology]

[0002] Climate change, including global warming, is increasing abiotic stress on plants, raising concerns about its impact on yield and quality. In Japan, temperatures rise significantly in the summer, causing heat stress on plants. High temperature stress can cause a decrease in germination rate, inhibition of early growth, elongation, and pests and diseases, even if the bed soil retains sufficient moisture. In addition, in greenhouse cultivation, it is difficult to lower the temperature at night, making it difficult to produce high-quality vegetables. Methods for dealing with high temperature stress include raising seedlings in cool nights, raising seedlings in cool highlands, and cultivating in a shaded area, but no sufficient methods have been established.

[0003] In recent years, the use of biostimulant materials has been attracting attention as a measure against environmental stresses on plants, such as high temperature stress. Biostimulant materials currently available on the domestic and international markets are made from humus, seaweed, amino acids, minerals, microbial materials, etc. For example, it has been reported that L-arginine promotes plant growth under high temperature conditions (see Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Matysiak, K. et al. (2020) Agronomy 10:769. doi: 10.3390 / agronomy10060769 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the effects of the above biostimulant materials are not sufficient, and therefore there is a need to develop more useful and powerful environmental stress alleviators and plant growth promoters.

[0006] An object of the present disclosure is to provide a new environmental stress alleviating agent and plant growth promoter for plants that have an excellent effect of alleviating environmental stresses such as high temperatures. [Means for solving the problem]

[0007] As a result of various investigations to solve the above problems, the present inventors have found that applying an extract of eggplant residue, which is one type of unused biomass, together with calcium ions to a plant can endow the plant with resistance to environmental stresses such as high temperatures, and that the effect is greater than that of conventional biostimulant materials. The present inventors have also found that when an extract of unused biomass other than eggplant residue is used, the same or greater effect can be obtained as with eggplant residue, and that these new materials can be manufactured in a simpler process than conventional biostimulant materials, and are easy to use. Based on these findings, the present disclosure has been completed.

[0008] That is, the present disclosure provides an agent for alleviating environmental stress for a plant, comprising a plant extract and calcium ions, and also provides a plant growth promoter, comprising a plant extract and calcium ions.

[0009] The present disclosure further provides a method for alleviating environmental stress in a plant by applying the above-mentioned plant environmental stress alleviator to the plant.The present disclosure also provides a method for promoting plant growth by applying the above-mentioned plant growth promoter to the plant. Effect of the Invention

[0010] In the present disclosure, by applying plant extracts such as eggplant together with calcium ions to plants, it is possible to endow the plants with resistance to environmental stresses such as high temperatures, and the effect is greater than that of conventional biostimulant materials. This effect is presumably due to the activation of the high temperature stress resistance function inherent to plants by neurotransmitters such as acetylcholine or acetylcholinesterase inhibitors and calcium ions contained in the plant extracts, but the detailed mechanism has not yet been elucidated.

[0011] Thus, according to the present disclosure, it is possible to provide a new environmental stress alleviating agent and plant growth promoter that have an excellent effect of alleviating environmental stresses such as high temperatures. [Brief description of the drawings]

[0012] [Figure 1A] FIG. 2 is a photographic image showing a high temperature resistance test using an eggplant sprout extract and an eggplant pulp extract (without added calcium) (Test Example 2). [Figure 1B] FIG. 2 is a photographic image showing a high temperature resistance test using eggplant sprout extract and eggplant pulp extract (calcium 0.5 mM) (Test Example 2). [Figure 1C] FIG. 2 is a photographic image showing a high temperature resistance test using eggplant sprout extract and eggplant pulp extract (calcium 1.0 mM) (Test Example 2). [Diagram 2] 1 is a graph showing the results of a high temperature resistance test (2 weeks) using eggplant sprout extract and eggplant pulp extract (Test Example 2). In the figure, the vertical axis shows yield (fresh weight (mg / plant)), the horizontal axis shows treatment group, the bars show standard deviation, and different letters show significant differences (LSD method) at the significance level of 5%. [Diagram 3] 1 is a graph showing calcium concentrations in lettuce seedlings after completion of the test in Test Example 2. In the figure, (A) shows the results with no calcium added, (B) shows the results with 0.5 mM calcium, and (C) shows the results with 1.0 mM calcium. In each graph, the vertical axis shows Ca concentration (%) and the horizontal axis shows yield (fresh weight (mg / plant)). [Figure 4]1 is a graph showing the results of a high temperature resistance test (2 weeks) using an environmental stress alleviator containing an extract from a plant other than eggplant (Test Example 3). In the figure, the vertical axis shows the relative yield (%) and the horizontal axis shows the treatment area. [Diagram 5] 1 is a graph showing the high temperature stress mitigation effect of various standard substances and calcium ions (Test Example 4). In the figure, the vertical axis shows the relative yield (%) and the horizontal axis shows the treatment area. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The environmental stress alleviator for plants according to the present embodiment will be described in detail below. The environmental stress alleviator according to the present embodiment is characterized by containing a plant extract and calcium ions.

[0014] As used herein, "environmental stress" refers to abiotic stress that a plant experiences, and examples of such stress include high temperature stress, low temperature stress, salt stress, oxidative stress, etc. The form of the environmental stress alleviator is not particularly limited, but it is preferably in the form of an aqueous solution.

[0015] The plant as the raw material for the "plant extract" is preferably unused biomass such as organic waste discharged from food processing plants and crop residues generated after harvesting in agriculture, from the viewpoint of reducing production costs and solving food waste problems. In addition, the plant preferably contains a neurotransmitter and / or an acetylcholinesterase inhibitor. The neurotransmitter may be one or more selected from acetylcholine, epinephrine, norepinephrine, serotonin, dopamine, amino acids (particularly glutamic acid, alanine, glycine, proline, leucine, threonine, phenylalanine, GABA, arginine, histidine, cysteine, and asparagine), preferably acetylcholine. The acetylcholinesterase inhibitor may be one or more selected from polyphenols, flavonoids, and organic acids, preferably one or more selected from malic acid, fumaric acid, and tocopherol.

[0016] The plant contains the neurotransmitter and / or the acetylcholinesterase inhibitor, and thus, for example, eggplant, broccoli, banana, coconut, mandarin orange, herbs (coriander, cumin, sage, lemongrass, mugwort, comfrey, sage, shiso, lemon balm, oregano, catnip, common thyme, thyme, dill, dark opal, basil, hyssop, peppermint, spearmint, lamb's ear), dokudami, lavender, marigold, grape, coffee (coffee plant), tea (camellia sinensis), cacao, acacia, cedar, maize , sugarcane, mango, banana, papaya, avocado, apple, cherry, guava, olive, potatoes (sweet potato, purple potato (sweet potato with a lot of purple pigment), potato, yam, taro (taro, shrimp potato, etc.), konjac, etc.), persimmon, mulberry, blueberry, poplar, ginkgo, chrysanthemum, sunflower, bamboo, citrus fruits (lemon, lime, orange, grapefruit, navel orange, yuzu, kumquat, kabosu, summer mandarin, hassaku, iyokan, lime, unshu mandarin, shekwasha, mandarin, etc.), strawberry, black Water berry, cranberry, raspberry, bilberry, huckleberry, plum, peach, plum, pear, European pear, loquat, kiwi fruit, mangosteen, shishito pepper, prune, melon, dragon fruit, wolfberry, black currant, cashew, viburnum, pomegranate, acai, aronia, tomato, soybean, black soybean, adzuki bean, green bean, peanut, black sesame, buckwheat, tartary buckwheat, sesame, purple cabbage, sumac, sumac tree, crown chrysanthemum, spinach, komatsuna, mitsuba, okra, butterbur, onion, mulukhiyah, garlic, purple onion, asparagus, parsley, eucalyptus, udo, gymnema Sylvestre, senna, dandelion, horsetail, fern (bracken, fern, etc.), oak, sawtooth oak, maple, sequoia, metasequoia, cypress, Mallotus japonicus, hawkweed, amacha, akebia, Japanese angelica, clematis, amplexicaule, magnolia, arguta, white-leafed cypress, Japanese cypress, Japanese cypress, Japanese cypress, Japanese cypress, Japanese cypress, Japanese cypress, Japanese honeysuckle, magnolia, silver vine, banaba, rooibos, rafuma, wolfberry, kudzu, Japanese bead tree, lily of the valley, melbourne, Chinese angelica, Chinese parasol tree, sappan, brazilian wood, melinjo, cherry blossom, magnolia, yerba mate, candel, mangrove, mangrove, sea pomegranate, nipa palm, mangrove,The plant may be any of mangrove, herbaceous tree, burdock, turmeric, lotus root, shepherd's purse, pine, carrot, green pepper, red pepper, paprika, bamboo, bamboo shoot, goldenrod, cassava, bamboo grass, clove, ginkgo, goldenrod, radish, mustard, etc., or processed products thereof. Among the above plants, eggplant, tomato, rosemary, bamboo grass, mint, eucalyptus, thyme, lemon balm, pine, coconut, bamboo, plum, chayote, lettuce, soybean, cassava, asparagus, mango, hibiscus, dandelion, horsetail, jolokia, and cacao are particularly suitable. The plant may be a part of the plant body, such as a stem, leaf, fruit, root, seed, rind, bud, flower, or rhizome. Two or more of these plants may be used in combination.

[0017] The "plant extract" may be an extract obtained by extracting the plant with an appropriate extraction solvent, an extract liquid, or a dried or purified product thereof. In addition, the squeezed juice of the plant, its concentrate, dried product, purified product, etc. are also included in the "plant extract" since they contain the same components as the extract. The concentration of the plant extract is not particularly limited, but the solid mass ratio when applied to the plant can be, for example, 1.000 ppm to 100.000 ppm in the case of hydroponic cultivation, and preferably 10.000 ppm to 80.000 ppm.

[0018] The "extraction solvent" is preferably water, hot water, alcohol (particularly ethanol), aqueous alcohol (particularly aqueous ethanol), or petroleum ether, but is not limited to these.

[0019] The "dried material" is preferably one that has been subjected to processing such as crushing, pulverization, or powdering, and a powder with a small particle size is particularly preferable.

[0020] The "calcium ion" may be a water-soluble salt of calcium, and is not particularly limited as long as it exerts the effect of alleviating environmental stress or promoting growth of a plant according to the present disclosure. The calcium ion may be, for example, an inorganic salt such as calcium sulfate or calcium chloride, or an organic acid salt such as calcium lactate, and calcium chloride is particularly preferred. The concentration of the calcium ion is not particularly limited, but the concentration when applied to a plant may be, for example, 0.001 mM to 100 mM in the case of hydroponic cultivation, and is preferably 0.01 mM to 10 mM, more preferably 0.1 mM to 1.0 mM, and particularly preferably 0.2 mM to 0.7 mM.

[0021] The environmental stress alleviation agent of the present embodiment may contain, in addition to the plant extract and the calcium ions, iron ions and other nutrients necessary for crop growth, other biostimulant materials, other plant growth promoters, fungicides, insecticides, plant hormones, and the like, so long as they do not inhibit the plant environmental stress alleviation or growth promotion effects of the present disclosure.

[0022] The "iron ion" may be a water-soluble salt of iron (II) or iron (III), and is not particularly limited as long as it does not inhibit the plant environmental stress alleviation or growth promotion effect of the present disclosure. The iron ion may be, for example, iron chloride (II), iron chloride (III), iron sulfate (II), iron sulfate (III), etc., and iron chloride (II) is particularly preferred. The concentration of the iron ion is not particularly limited, but the concentration when applied to a plant may be, for example, 0.001 mM to 100 mM in the case of hydroponic cultivation, preferably 0.01 mM to 10 mM, more preferably 0.1 mM to 1.0 mM, and particularly preferably 0.2 mM to 0.7 mM.

[0023] The "other nutrients necessary for crop growth" that may be contained in the environmental stress alleviation agent may be, for example, trace elements other than iron (boron, manganese, zinc, copper, molybdenum, etc.) or macroelements (nitrogen, phosphate, potassium), and the above-mentioned trace elements are preferred, but are not limited to these.

[0024] Plants to which the environmental stress alleviation agent of the present embodiment can be applied are not particularly limited, and include, for example, vegetables such as leafy vegetables, fruit vegetables, root vegetables, and flower vegetables, grains such as rice and wheat, flowers, and fruit trees, and preferably include lettuce, garland chrysanthemum, cabbage, spinach, tomato, eggplant, and paprika.

[0025] Next, a method for producing the environmental stress alleviator for plants according to the present embodiment will be described. The environmental stress alleviator for plants according to the present embodiment can be produced by mixing the plant extract and the calcium ions in the presence of water.

[0026] The plant extract can be obtained by extracting the above-mentioned plant with the above-mentioned extraction solvent. The extraction conditions are not particularly limited. After extraction, purification, concentration, drying, and other operations can be performed.

[0027] The mixing operation of the plant extract and the calcium ions is carried out in the presence of water. Here, "in the presence of water" refers to any condition under which the plant extract and the calcium ions can react with water as a medium. The amount of water is at least an amount that allows mixing and stirring of the plant extract and the calcium ions, and may be an amount that wets the mixture of the plant extract and the calcium ions. When the plant extract is a liquid such as a squeezed juice or extract of a plant, or when the calcium ions are used in the form of an aqueous solution, the two can be mixed directly without adding a new medium.

[0028] The mixing operation may be performed by simple stirring and mixing using a stirrer or the like, but may also be performed using a mixer, a large stirring tank, a vortex, a shaker, or the like. The temperature conditions during mixing are not particularly limited, and may be, for example, about room temperature (e.g., 10 to 35°C). The mixing time is not particularly limited, and may be until the plant extract and calcium ions are sufficiently in contact with each other.

[0029] The plant environmental stress alleviator thus obtained is considered to have the function of turning on various stress resistance mechanisms inherent to plants, such as high temperature resistance, low temperature resistance, salt stress resistance, and oxidative stress resistance. Therefore, it is expected that the plant environmental stress alleviator according to the present embodiment can artificially control the plant's environmental stress resistance mechanism by applying it to a plant. For example, when a plant cell is exposed to environmental stress such as high temperature, an inflow of calcium ions from outside the cell is caused through an ion channel. The plant environmental stress alleviator according to the present embodiment is considered to be able to activate calcium signal transduction in the cell by opening this ion channel, thereby endowing the plant with environmental stress resistance. There is no particular limitation on the plants to which the environmental stress alleviator according to the present embodiment can be applied.

[0030] Furthermore, the environmental stress alleviator of the present embodiment can promote plant growth under environmental stress by imparting environmental stress resistance to the plant, and therefore the environmental stress alleviator of the present embodiment can also be called a plant growth promoter.

[0031] Next, a method for using the environmental stress alleviator of the present embodiment will be described. The environmental stress alleviator of the present embodiment can be used by applying an effective amount to a plant in the same manner as conventional fertilizers, plant growth promoters, and biostimulant materials. The effective amount may be an amount that exerts an environmental stress alleviation or plant growth promotion effect on the plant.

[0032] For example, in the case of hydroponic cultivation, a method of adding an appropriate amount of the environmental stress alleviator of the present embodiment to a hydroponic solution is simple and preferable. Also, for example, the environmental stress alleviator of the present embodiment may be sprayed or applied in an appropriate amount to the leaf surface of a plant. Also, for example, it may be irrigated into the soil in which the plant is growing, treated on seeds, or mixed with other agricultural materials such as liquid fertilizers, plant growth promoters, and biostimulant materials.

[0033] The amount and concentration of the environmental stress alleviator of the present embodiment added to a hydroponic solution or other agricultural materials may be appropriately adjusted so that the concentrations of the plant extract and calcium ions contained in the environmental stress alleviator are within the above-mentioned ranges, or so that an environmental stress alleviation or plant growth promotion effect is achieved for plants. The timing and frequency of use of the environmental stress alleviator can be appropriately set according to the period when the crop is susceptible to environmental stress, and are not particularly limited.

[0034] The method of using the environmental stress alleviator of this embodiment as a plant growth promoter is similar to that described above. EXAMPLES

[0035] The present embodiment will now be described in detail with reference to examples.

[0036] (Test Example 1) High temperature resistance test using lettuce seedlings (part 1) Many vegetables cultivated in Japan have low high-temperature tolerance. Lettuce is also adapted to relatively cool weather conditions, and the optimum temperature for growth is 18 to 23°C. When head lettuce is cultivated at high temperatures, abnormal heads such as oversized heads, small heads, bamboo shoot heads, and heads with protruding midribs are likely to occur, and physiological disorders (tip burn) caused by Ca deficiency are problematic. Conventionally, tests to confirm high-temperature tolerance of crops based on these symptoms took several months. Therefore, the inventor of the present application developed a model experimental system to examine whether lettuce has acquired high-temperature tolerance by performing a two-week high-temperature cultivation test, taking advantage of the fact that high-temperature and long-day conditions induce the differentiation of flower buds and bolts and elongate the stems in lettuce seedlings.

[0037] (1) Preparation of environmental stress alleviating agent using eggplant residue As eggplant residues, (a) 50g of flesh from which the skin was removed after harvesting eggplant, (b) 20g of sprouts removed during cultivation management of eggplants, (c) 20g of skin from harvesting eggplants, and (d) 20g of roots from harvesting eggplants were used. Each of these eggplant residues was placed in a 1L beaker, 700mL of distilled water was added thereto, and heated at 120°C for 20 minutes. The supernatant was then filtered through filter paper, and boric acid (3g), manganese sulfate (2g), zinc sulfate (0.22g), copper sulfate (0.05g), sodium molybdate (0.01g), ferrous sulfate (15g), and calcium chloride (55g) were added to the filtrate (eggplant residue extract), and distilled water was further added to obtain 1L of eggplant residue mixtures (a-d). Note that eggplant residue mixtures (a'-d') without calcium ions were prepared in the same manner as above, except that calcium chloride was not added, and used as comparative examples.

[0038] (2) Hydroponic cultivation test of lettuce seedlings 1 mL of each of the following nutrient solutions A to D was combined with 1 mL of any of the eggplant residue mixtures (a to d, a' to d') prepared above, and distilled water was added to prepare 1 L of hydroponic solution. The amount of nutrient solution used to prepare each hydroponic solution (1 L) is shown in Table 1. The concentrations of calcium and trace elements in each hydroponic solution were 0.05 mM boric acid, 0.01 mM manganese sulfate, 0.001 mM zinc sulfate, 0.0003 mM copper sulfate, 0.0005 mM sodium molybdate, 0.1 mM ferrous sulfate, and 0.5 mM calcium chloride. The solids concentration of the eggplant residue extract in each hydroponic solution was 50,000 mg / L for flesh (a, a'), 20,000 mg / L for buds (b, b'), 20,000 mg / L for skin (c, c'), and 20,000 mg / L for roots (d, d').

[0039] Nutrient solution A: 700 mL of distilled water and 202 g of KNO3 were placed in a 1 L beaker and stirred until dissolved, and further distilled water was added to make 1 L. Nutrient solution B: 700 mL of distilled water and 178 g of KH2PO4 were placed in a 1 L beaker and stirred until dissolved, and further distilled water was added to make 1 L. Nutrient solution C: 700 mL of distilled water and 44 g of NH4NO3 were placed in a 1 L beaker and stirred until dissolved, and further distilled water was added to make 1 L. Nutrient solution D: 700 mL of distilled water and 489 g of MgSO4·7H2O were added to a 1 L beaker and stirred until dissolved, then further distilled water was added to make 1 L.

[0040] The prepared hydroponic solutions were placed in 1.2 L simple hydroponic cultivation devices, and lettuce seedlings (10 days after sowing) were planted and cultivated for 14 days under cultivation conditions of 12 h light / 35°C, 12 h dark / 25°C, and 60% humidity. As a control, hydroponic solutions prepared without adding the eggplant residue mixture (a-d, a'-d') were used. After 14 days of cultivation, the lettuce was harvested and the yield was measured.

[0041] [Table 1]

[0042] (3) Results and Discussion The results are shown in Table 2. The values ​​in Table 2 show the relative yield (%, fresh weight ratio) in each treatment plot when the yield in each control plot (nutrient solutions A to D only) is taken as 100%. Table 2 shows that the treatment plots using a hydroponic solution containing added eggplant residue extract and calcium ions (calcium chloride) had a significantly increased yield of 4 to 10.5 times compared to the comparative example treatment plots using a hydroponic solution without added calcium ions. These results show that the growth of lettuce seedlings is greatly promoted under high temperature conditions (25°C to 35°C) by cultivating them with the addition of the environmental stress alleviator of this embodiment to the hydroponic solution, and high temperature stress resistance is imparted to them.

[0043] [Table 2]

[0044] (Test Example 2) High temperature resistance test using lettuce seedlings (part 2) Next, we investigated the effect of changing calcium concentration on mitigating high temperature stress.

[0045] (1) Preparation of environmental stress alleviating agent using eggplant residue As eggplant residue, 20 g of sprouts removed during eggplant cultivation management and 50 g of fruit (with skin) after harvesting were used. Each of these eggplant residues was placed in a 1 L beaker, 1000 mL of distilled water was added thereto, and heated at 120 ° C for 20 minutes. The supernatant was then filtered through filter paper, and boric acid (3 g), manganese sulfate (2 g), zinc sulfate (0.22 g), copper sulfate (0.05 g), sodium molybdate (0.01 g), ferrous sulfate (15 g), calcium chloride (55 g or 110 g) were added to the filtrate (eggplant residue extract), and distilled water was further added to obtain 1 L of eggplant sprout mixture and eggplant fruit mixture. In addition, eggplant sprout mixture and eggplant fruit mixture without calcium ion addition were prepared in the same manner as above except that calcium chloride was not added, and used as comparative examples.

[0046] (2) Hydroponic cultivation test of lettuce seedlings 1 mL of each of the nutrient solutions A to D in Test Example 1 was mixed with 1 mL of either the eggplant sprout mixture or the eggplant fruit mixture prepared above, and distilled water was added to prepare 1 L of hydroponic solution. The amount of nutrient solution used to prepare each hydroponic solution (1 L) is shown in Table 3. The concentrations of calcium and trace elements in each hydroponic solution were 0.05 mM boric acid, 0.01 mM manganese sulfate, 0.001 mM zinc sulfate, 0.0003 mM copper sulfate, 0.0005 mM sodium molybdate, 0.1 mM ferrous sulfate, and 0.5 mM or 1.0 mM calcium chloride. The solids concentration of the eggplant residue extract in each hydroponic solution was 20.000 mg / L for sprouts and 50.000 mg / L for fruits.

[0047] The prepared hydroponic solutions were placed in 1.2 L simple hydroponic cultivation vessels, and lettuce seedlings (10 days after sowing) were planted and cultivated for 14 days under cultivation conditions of 12 h light / 35°C, 12 h dark / 25°C, and 60% humidity. As a control, hydroponic solutions to which a specified amount of calcium chloride aqueous solution had been added were used instead of the eggplant sprout mixture and eggplant fruit mixture. After 14 days of cultivation, the lettuce was harvested and the yield was measured, and the Ca concentration in the plants was measured using an ICP emission spectrometer.

[0048] [Table 3]

[0049] (3) Results and Discussion The results are shown in Table 4 and Figures 1A, B, C, Figures 2 and 3. Figures 1A, B, and C are photographs showing the high temperature tolerance test, with Figure 1A showing the treatments with no calcium added, Figure 1B showing 0.5 mM calcium, and Figure 1C showing 1.0 mM calcium. Figure 2 is a graph showing the measured lettuce yield, and Figure 3 is a graph showing the relationship between lettuce yield and calcium concentration. The values ​​in Table 4 and Figure 2 represent the relative yield (%, fresh weight ratio) in each treatment when the yield in each control group is taken as 100%.

[0050] In Figure 1A (no calcium added), leaves in all treatments turned yellow, and symptoms of calcium deficiency due to high temperature damage appeared, but in Figure 1B (0.5 mM calcium), high temperature damage was not observed in the treatments with eggplant residue extract compared to the control (untreated) without eggplant residue extract, and growth was clearly promoted. In Figure 1C (1.0 mM calcium), no leaf damage was observed in the control (untreated), but a clear growth promotion effect was observed in the treatments with eggplant residue extract.

[0051] Table 4 and Fig. 2 show that the treatment plots using hydroponic solutions containing added eggplant residue extract and calcium ions (calcium chloride) showed a large and significant increase in yield, 2 to 6.5 times, compared to the control plots using hydroponic solutions containing no added eggplant residue extract, at all calcium ion concentrations. In contrast, no significant difference was observed in the treatment plots without added calcium ions compared to the control plots (nutrient solutions A to D only). These results show that by cultivating lettuce seedlings by adding the environmental stress alleviator of this embodiment to a hydroponic solution, the growth of the lettuce seedlings is greatly promoted under high temperature conditions (25°C to 35°C), and high temperature stress resistance is imparted to them.

[0052] 3(B) and (C) show that calcium ion concentration increased in the treatment area where the environmental stress alleviator of the present embodiment was applied. In addition, since the higher the calcium ion concentration in the plant, the higher the yield tends to be, it was suggested that the increase in calcium ion concentration is related to the acquisition of high temperature resistance. As mentioned above, it is believed that the increase in calcium ion concentration in the cells switches on various stress resistance mechanisms in the plant. Therefore, it was speculated that the environmental stress alleviator of the present embodiment has the effect of alleviating various environmental stresses other than high temperature stress.

[0053] [Table 4]

[0054] (Test Example 3) Comparison with unused biomass other than eggplant residue The environmental stress alleviation agent of the present embodiment was prepared using unused biomass other than eggplant residue, and the effects were compared.

[0055] (1) Preparation of environmental stress relief agent Various crop residues were used, as shown in Table 5 below. The amount of each crop residue shown in Table 5 was placed in a 1-L beaker, 700 mL of distilled water was added, and the mixture was heated at 120°C for 20 minutes. The supernatant was then filtered through filter paper to obtain a filtrate (crop residue extract). Boric acid (3 g), manganese sulfate (2 g), zinc sulfate (0.22 g), copper sulfate (0.05 g), sodium molybdate (0.01 g), ferrous sulfate (15 g), and calcium chloride (55 g) were added to the filtrate, and distilled water was then added to obtain 1 L of each crop residue mixture.

[0056] [Table 5]

[0057] (2) Hydroponic cultivation test of lettuce seedlings 1 mL of each of the nutrient solutions A to D in Test Example 1 was mixed with 1 mL of any of the crop residue mixtures prepared above, and distilled water was added to prepare 1 L of hydroponic solution. The solid concentration of the crop residue extract in each hydroponic solution was 10,000 mg / L.

[0058] The prepared hydroponic solutions were placed in a 1.2 L simple hydroponic cultivation vessel, and lettuce seedlings (10 days after sowing) were planted and cultivated for 14 days under cultivation conditions of 12 h light / 35°C, 12 h dark / 25°C, and 60% humidity. As a control, a hydroponic solution containing 1 mL of 0.5 M calcium chloride aqueous solution was used instead of the crop residue mixed solution. As a comparative example, a hydroponic solution containing humus (humic acid 0.3 g / L) and amino acids (glutamic acid 0.1 mM), which have been reported to have high temperature stress mitigation effects, was used instead of the crop residue mixed solution. After 14 days of cultivation, the lettuce was harvested and the yield was measured.

[0059] (3) Results and Discussion The results are shown in Table 6 and FIG. 4. The values ​​in Table 6 and FIG. 4 show the relative yield (%, fresh weight ratio) in each treatment area when the yield in the control area is taken as 100%. Table 6 and FIG. 4 show that the treatment area using the hydroponic solution to which the crop residue extract and calcium ions (calcium chloride) were added had a significantly increased yield of 2 to 11 times compared to the control area using the hydroponic solution to which no crop residue extract was added. In particular, the environmental stress relief agents using eggplant, tomato, rosemary, bamboo grass, mint, eucalyptus, thyme, lemon balm, pine, coconut, bamboo, plum, chayote, lettuce, soybean, cassava, asparagus, mango, hibiscus, dandelion, horsetail, jolokia, and cacao showed a remarkable effect compared to the humus and amino acids of the conventional technology. From these results, it was found that the environmental stress relief agent of the present embodiment can impart high temperature stress resistance to plants even when using plant extracts other than eggplant.

[0060] [Table 6] **As a conventional technique, humus (humic acid 0.3 g / L) and amino acids (glutamic acid 0.1 mM) were used.

[0061] (Test Example 4) Effect of standard substances on reducing high temperature stress It is believed that the environmental stress alleviator for plants of the present embodiment can activate intracellular Ca signal transduction and endow the plant with environmental stress resistance. In addition, Test Example 2 suggested that there is a correlation between improved high temperature resistance and increased Ca concentration in the plant. Therefore, in this test example, the environmental stress alleviation effect was investigated when a standard substance known as a neurotransmitter or acetylcholinesterase inhibitor that causes the influx of Ca ions into cells was used together with calcium ions, with the aim of helping to clarify the mechanism of the present disclosure.

[0062] (1) Test method 20 g of each of the standard substances shown in FIG. 5 was taken, and boric acid (3 g), manganese sulfate (2 g), zinc sulfate (0.22 g), copper sulfate (0.05 g), sodium molybdate (0.01 g), iron sulfate (15 g), and calcium chloride (55 g) were added thereto, and distilled water was further added thereto to obtain 1 L of each standard substance mixture. Next, 1 mL of each of the nutrient solutions A to D of Test Example 1 was combined with 1 mL of any of the standard substance mixtures prepared above, and distilled water was further added to prepare 1 L of hydroponic solution. The prepared hydroponic solutions were each placed in a 1.2 L simple hydroponic cultivation vessel, and lettuce seedlings (10 days after sowing) were planted and cultivated for 14 days under cultivation conditions of 12 h light / 35°C, 12 h dark / 25°C, and 60% humidity. As a control (untreated), hydroponic solution to which 1 mL of 0.5 M calcium chloride aqueous solution was added instead of the standard substance mixture was used. As a comparative example, hydroponic solution containing GABA (final concentration 0.516 g / L), humic acid (final concentration 0.3 g / L), and alanine (final concentration 0.5 g / L), which have been reported to have high temperature stress alleviating effects, was used instead of the standard substance. After 14 days of cultivation, the lettuce was harvested and the yield was measured.

[0063] (2) Results and Discussion The results are shown in FIG. 5. The values ​​in FIG. 5 represent the relative yield (%, fresh weight ratio) in each treatment area when the yield in the control area (untreated) is taken as 100%. FIG. 5 shows that the treatment areas using malic acid, fumaric acid, acetylcholine, tocopherol, and succinic acid had a significantly increased yield compared to the control area and the treatment areas of the comparative example. Acetylcholine is a neurotransmitter known to be contained in many plants, and malic acid, fumaric acid, and tocopherol are all acetylcholinesterase inhibitors contained in plants. This result suggests that it is highly likely that these acetylcholine and acetylcholinesterase inhibitors act as active ingredients in the environmental stress relief agent of this embodiment. [Industrial Applicability]

[0064] As shown in the above examples, by applying the environmental stress alleviator containing the plant extract and calcium ions according to the present disclosure to a plant, it is possible to impart resistance to environmental stress to the plant while maintaining a sufficient growth-promoting effect. Furthermore, the environmental stress alleviator according to the present disclosure can utilize unused biomass such as crop residues generated in agriculture and waste from food processing plants as raw materials. Therefore, the present disclosure can be used in the agricultural and food processing industries.

Claims

1. An environmental stress relief agent for plants containing plant extracts and calcium ions.

2. The agent for alleviating environmental stress for plants according to claim 1 , wherein the plant extract is an extract of a plant containing an acetylcholine or acetylcholinesterase inhibitor.

3. 2. The agent for alleviating environmental stress for plants according to claim 1, wherein the plant extract is an extract of one or more plants selected from the group consisting of eggplant, tomato, rosemary, bamboo, mint, eucalyptus, thyme, lemon balm, pine, coconut, bamboo, plum, chayote, lettuce, soybean, cassava, asparagus, mango, hibiscus, dandelion, horsetail, jolokia, and cacao.

4. The agent for alleviating environmental stress for plants according to claim 1 , further comprising iron ions and trace elements.

5. 2. The agent for alleviating environmental stress for plants according to claim 1, wherein the calcium ions are contained at a concentration of 0.001 mM to 100 mM when applied to plants.

6. The agent for alleviating environmental stress for plants according to claim 1 , which is used by being added to a hydroponic solution.

7. The agent for alleviating environmental stress for plants according to claim 1, which is applied to one or more plants selected from the group consisting of lettuce, garland chrysanthemum, cabbage, spinach, tomato, and eggplant.

8. A plant growth promoter containing plant extracts and calcium ions.

9. A method for alleviating environmental stress in a plant, comprising applying the agent for alleviating environmental stress for a plant according to any one of claims 1 to 7 to the plant.

10. A method for promoting plant growth, which comprises applying the plant growth-promoting agent according to claim 8 to a plant.

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