Application of 3-methylpyrrolidine-2-carboxylic acid in promoting plant growth

Abstract

The invention discloses an application of 3-methylpyrrolidine-2-carboxylic acid in promotion of plant growth and a preparation method of the 3-methylpyrrolidine-2-carboxylic acid. The invention relates to application of 3-methylpyrrolidine-2-carboxylic acid in preparation of a plant growth promoter. According to the invention, the 3-methylpyrrolidine-2-carboxylic acid is found to be used for seed soaking treatment and root irrigation treatment, so that the growth and development of plants can be promoted. The 3-methylpyrrolidine-2-carboxylic acid is convenient to use, the production problem which cannot be solved by the traditional agriculture is solved, and the production cost is saved. Besides, the 3-methylpyrrolidine-2-carboxylic acid is a natural metabolite with a simple structure, belongs to alpha-amino acid, has very high environmental and biological safety, and belongs to the field of green and efficient biochemical pesticides.

Description

Technical Field

[0001] The invention belongs to the field of agricultural biological pesticides and relates to the application of 3-methylpyrrolidine-2-carboxylic acid as a plant growth regulator. Background Art

[0002] The growth and development of plants not only requires the supply of resources such as light, water, and nutrients, but is also regulated by growth substances. Plant growth substances mainly include two categories: plant hormones and growth regulators. Plant growth regulators refer to artificially synthesized or extracted compounds with the physiological activity of natural plant hormones, which can be used to regulate or control certain processes of plant growth and development, such as cell division and elongation, tissue and organ differentiation, seed dormancy and germination, flowering and fruiting, maturity and aging, etc., in order to achieve the purpose of promoting or inhibiting seed germination, plant growth, fruit ripening, flower and fruit preservation or flower and fruit thinning, improving plant immunity, helping plants resist adverse environments, reducing diseases, increasing crop yields, and improving crop quality. Due to its significant and efficient regulatory effect, it has been widely used in various aspects such as food, fruit trees, forests, vegetables, and flowers. At present, my country has become one of the countries with the most extensive application of plant growth regulators in the world.

[0003] Plant growth regulators have played a huge role in regulating crop growth, solving many problems that cannot be solved by traditional agronomic methods, and have made important contributions to my country's agricultural production and development. They have become one of the main measures to increase agricultural production, improve quality and increase efficiency. However, plant growth regulators are a type of pesticide and are also toxic. Food safety issues caused by blind and excessive use of plant growth regulators are still widespread, and international standards for plant growth regulator residue limits are becoming increasingly stringent. Therefore, it is particularly important to develop low-toxic, high-efficiency, and environmentally friendly plant growth regulators.

[0004] 3-Methylpyrrolidine-2-carboxylic acid, molecular formula C 6 H 11 NO 2, molecular weight 129 g / mol, colorless crystals. The earliest report on this compound was in 1964, when 3-methylpyrrolidine-2-carboxylic acid was first obtained by chemical synthesis. Subsequent activity studies found that this compound can inhibit the synthesis of actinomycin in Streptomyces antibioticus, and chloramphenicol can relieve this inhibition (Yoshida et al., 1964; Mauger et al., 1966; Katz et al., 1968; Yoshida et al., 1968). Recently, we successfully isolated and purified 3-methylpyrrolidine-2-carboxylic acid from Alternata sp., which is one of the main saprophytic plant pathogenic fungi widely present in nature. This is also the first time that natural wild-type microorganisms have been found to produce 3-methylpyrrolidine-2-carboxylic acid, and at a high content. We studied its plant immune induction activity and found that it can induce plant immune response, thereby resisting fungal, bacterial and viral diseases; at the same time, it can induce plants to resist high and low temperature and drought stress (Chinese patent 202210737446.7). However, there are no studies, reports or patents on the plant growth promoting activity of 3-methylpyrrolidine-2-carboxylic acid. This is the innovation of this patent. Summary of the invention

[0005] The purpose of the present invention is to provide the use of 3-methylpyrrolidine-2-carboxylic acid as a growth regulator to promote plant growth in view of the above-mentioned deficiencies in the prior art.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] Application of 3-methylpyrrolidine-2-carboxylic acid in promoting the growth of plant seedlings.

[0008] As a preferred embodiment of the present invention, 3-methylpyrrolidine-2-carboxylic acid is used to promote the occurrence and growth of plant seedling root systems by seed soaking.

[0009] As a preferred embodiment of the present invention, 3-methylpyrrolidine-2-carboxylic acid is used to promote the growth of plant seedlings through root irrigation treatment.

[0010] The plants are selected from food crops and vegetables. The food crops are preferably rice, and the vegetables are preferably cucumbers.

[0011] Application of 3-methylpyrrolidine-2-carboxylic acid in the preparation of plant growth regulators.

[0012]

[0013] The existing related research on 3-methylpyrrolidine-2-carboxylic acid has not involved any reports in the field of plant growth regulators. 3-methylpyrrolidine-2-carboxylic acid performs well in related experiments to promote plant growth, and can promote plant growth and increase yield. Its details and implementation plan are as follows:

[0014] A method for promoting plant growth, comprising applying 0.01-1 μM 3-methylpyrrolidine-2-carboxylic acid solution to a target plant; the target plant is selected from food crops and vegetables; the food crop is preferably rice, and the vegetable is preferably cucumber.

[0015] As a preferred embodiment of the present invention, a method for promoting rice seed germination using 3-methylpyrrolidine-2-carboxylic acid, a natural product isolated from the plant pathogenic fungus Alternaria alternata, can significantly promote rice seed germination by treating rice seeds in a concentration range of 0.01-1 μM by soaking the seeds; especially when the concentration is 0.1 μM, the root length of rice is increased by 57% compared with the blank control.

[0016] As a preferred embodiment of the present invention, 3-methylpyrrolidine-2-carboxylic acid is used in a method for promoting the growth of rice seedlings. The method can significantly promote the growth of rice seedlings by treating rice seeds in a seed soaking manner at a concentration range of 0.01-1 μM. In order to further screen the optimal concentration for seed soaking, on the basis of the above experiments, the concentration of 3-methylpyrrolidine-2-carboxylic acid is reduced to between 0.1 μM and 0.4 μM for experiments. When the concentration is 0.2 μM, the effect on promoting the occurrence of rice root system and plant growth is most significant. Compared with the blank control group, the plant height, root length and root fresh weight are increased by 17%, 29% and 63%, respectively.

[0017] As a preferred embodiment of the present invention, 3-methylpyrrolidine-2-carboxylic acid is used in a method for promoting rooting of cucumber seedlings. The method can significantly promote cucumber seed germination by treating cucumber seeds by soaking them in a concentration range of 0.01-1 μM; especially when the concentration is 0.1 μM, the root length of the cucumber seedlings increases by 85% compared with the blank control.

[0018] As a preferred embodiment of the present invention, 3-methylpyrrolidine-2-carboxylic acid is used for the method of promoting the growth of cucumber seedlings. When the concentration is 0.01-1 μM, the cucumber seedlings are treated with root irrigation to significantly promote the growth of cucumber seedlings; especially when the concentration is 0.25 μM, the first true leaf area, the second true leaf area, the third true leaf area, the plant height, the root length, the whole plant fresh weight, and the root fresh weight at 18 days are increased by 38%, 46%, 210%, 4%, 55%, 70%, and 99% respectively compared with the blank control group; the chlorophyll a, chlorophyll b, total chlorophyll content, PI in the third true leaf at 18 days ABS and PI totalThey increased significantly by 32%, 26%, 31%, 10.7% and 44.8% respectively.

[0019] The main advantages and positive effects of the present invention are as follows:

[0020] 3-Methylpyrrolidine-2-carboxylic acid is a natural product with a simple structure and is easy to produce industrially. Since the present invention confirms that 3-methylpyrrolidine-2-carboxylic acid can promote plant growth, it has the potential to be developed into a natural plant growth regulator.

[0021] The invention finds that 3-methylpyrrolidine-2-carboxylic acid can effectively promote plant growth through seed soaking and root irrigation treatment. At a concentration of 0.1 μM, seed soaking can promote rice seed germination and significantly improve the growth of rice seedling rhizomes; at a concentration of 0.2 μM, seed soaking can promote the growth of rice seedlings and significantly improve the plant height and root fresh weight of the seedlings; at a concentration of 0.1 μM, seed soaking can promote cucumber seed germination and significantly improve the root length of the cucumber seedlings; at a concentration of 0.25 μM, root irrigation is used to treat cucumber soil-cultured seedlings to promote the growth of the cucumber seedlings, and the leaf area, plant height, root length, fresh weight, chlorophyll content and photosystem II comprehensive performance index of the cucumber seedlings can be significantly improved.

[0022] 3-Methylpyrrolidine-2-carboxylic acid is a natural product with low usage, is environmentally friendly, and has a significant promoting effect on plant growth. It is therefore a green and efficient biogenic plant growth regulator, which indicates the utilization value and application prospects of this type of substance in agricultural production.

[0023] The present invention finds that 3-methylpyrrolidine-2-carboxylic acid can promote plant growth and development by seed soaking and root irrigation. 3-methylpyrrolidine-2-carboxylic acid is easy to use, solves production problems that cannot be solved by traditional agronomy, and saves production costs. In addition, since 3-methylpyrrolidine-2-carboxylic acid is a naturally occurring metabolite with a simple structure and belongs to α-amino acid, it has high environmental and biological safety and belongs to the category of green and efficient biochemical pesticides. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Effects of soaking seeds with different concentrations of 3-methylpyrrolidine-2-carboxylic acid on germination of rice seeds.

[0025] Figure 2 Effects of seed soaking with different concentrations of 3-methylpyrrolidine-2-carboxylic acid on the growth of rice seedlings.

[0026] Figure 3 Effects of seed soaking with different concentrations of 3-methylpyrrolidine-2-carboxylic acid on cucumber seed germination.

[0027] Figure 4Effects of root irrigation with different concentrations of 3-methylpyrrolidine-2-carboxylic acid on the growth of cucumber seedlings. DETAILED DESCRIPTION

[0028] The inventors have studied the biological activity, application scope and crop safety of 3-methylpyrrolidine-2-carboxylic acid and found that the substance also has a very unique effect in regulating crop growth, and has the advantages of being environmentally friendly, widely applicable and safe to use. It is a natural plant growth regulator and has the potential to be developed into a biological pesticide. The essential features of the present invention can be reflected from the following embodiments and examples, but these should not be regarded as any limitation of the invention.

[0029] Example 1: Effect of Seed Soaking with 3-Methylpyrrolidine-2-Carboxylic Acid on Germination of Rice Seeds

[0030] The rice seeds (variety "Dengliangyou 2108") were rinsed with distilled water, disinfected with 75% alcohol for 3 minutes, washed with distilled water 3 times, and then disinfected with NaClO (5%) for about 10 minutes. After taking out, they were rinsed with distilled water, and then the residual moisture on the surface of the seeds was absorbed with clean filter paper until the surface was dry. 4g of healthy, plump and uniform seeds were selected and placed in a 50mL centrifuge tube. 8mL of clean water, 3-methylpyrrolidine-2-carboxylic acid with concentrations of 0.01, 0.1 and 1μM and 0.1g / L (260μM, recommended concentration for production) gibberellin aqueous solution were added to each tube. Stir the seeds to completely immerse them in the liquid medicine. After soaking the seeds at room temperature for 48 hours, they were directly germinated without rinsing. Each group of experiments was repeated three times. In each repeat, 30 rice seeds were randomly selected with tweezers and placed in a culture dish pre-laid with moist filter paper, and placed in a 28℃ culture room for germination culture. After 3 days, the seed germination rate, sprout length and root length were measured and recorded.

[0031] Table 1 Effects of soaking rice seeds with different concentrations of 3-methylpyrrolidine-2-carboxylic acid (MPRO) on germination of rice seeds

[0032]

[0033] The results in Table 1 show that the stem and root lengths of rice seedlings increased to varying degrees under the treatment of 0.01μM, 0.1μM and 1μM 3-methylpyrrolidine-2-carboxylic acid solution. Compared with the blank control, the germination rate of rice seeds increased significantly by 5%, 4% and 5% after soaking in 0.01μM, 0.1μM and 1μM 3-methylpyrrolidine-2-carboxylic acid solution, and the root length increased significantly by 14%, 57% and 29% respectively. At 0.1μM and 1μM concentrations, the stem length increased significantly by 40% and 20% respectively. When 3-methylpyrrolidine-2-carboxylic acid was greater than 0.1μM, the promotion effect on rice seedlings was no longer significantly increased. After soaking in 0.1g / L gibberellin, the germination rate of rice seeds increased by 5%, and the stem and root lengths increased significantly by 60% and 29% respectively compared with the control. Judging from the results, the effect of promoting the root and stem growth of rice seedlings was best when treated with 3-methylpyrrolidine-2-carboxylic acid at a concentration of 0.1 μM. However, in terms of promoting stem growth, 3-methylpyrrolidine-2-carboxylic acid at a concentration of 0.1 μM was slightly worse than 0.1 g / L gibberellin (about 260 μM); in terms of promoting root growth, 3-methylpyrrolidine-2-carboxylic acid performed significantly better than gibberellin. Considering that during the rice seedling cultivation process, rapid stem growth can easily lead to tall seedlings and slender stems, which is not conducive to strong seedlings. Therefore, strengthening roots is more important than promoting stem growth in the rice seedling stage. Therefore, 3-methylpyrrolidine-2-carboxylic acid has better seedling strengthening effects and application potential than gibberellin.

[0034] Example 2: Effect of Seed Soaking with 3-Methylpyrrolidine-2-Carboxylic Acid on the Growth of Rice Seedlings

[0035] The rice seeds (variety "Dengliangyou 2108") were rinsed with distilled water, disinfected with 75% alcohol for 3 minutes, washed with distilled water 3 times, and then disinfected with NaClO (5%) for about 10 minutes. After taking out, rinsed with distilled water, and then the residual water on the surface of the seeds was absorbed with clean filter paper until the surface was dry. 4g of healthy, plump and uniform seeds were selected and placed in a 50mL centrifuge tube. 8mL of clean water, 3-methylpyrrolidine-2-carboxylic acid with concentrations of 0.01, 0.1 and 1μM and 0.1g / L gibberellin aqueous solution were added to each tube respectively. Stir to make the seeds completely immersed in the liquid. After soaking at room temperature for 5 days, 100 rice seeds with the same germination state for testing were selected respectively, and evenly sown in the rice seedling tray, covered with soil, and the seedling tray was placed in a 28℃ culture room. When the rice seedlings grew to three leaves and one heart, the whole plant was taken out, and the plant height, root length and chlorophyll content of the seedlings were measured respectively. The results are shown in Table 2.

[0036] Table 2 Effects of different concentrations of 3-methylpyrrolidine-2-carboxylic acid (MPRO) soaking on the growth of rice seedlings

[0037]

[0038] The results showed that the phenotype and biomass of rice seeds treated with 3-methylpyrrolidine-2-carboxylic acid were significantly different from those treated with water. The plant height, root length and root fresh weight of rice plants increased to varying degrees under the treatment of 0.01μM, 0.1μM and 1μM 3-methylpyrrolidine-2-carboxylic acid solution. Compared with the blank control, the plant height increased significantly by 7%, 19% and 10%, the root length increased significantly by 11%, 22% and 12%, and the root fresh weight increased significantly by 12%, 35% and 19% after the seeds were soaked in 0.01μM, 0.1μM and 1μM 3-methylpyrrolidine-2-carboxylic acid solution, respectively. When 3-methylpyrrolidine-2-carboxylic acid was greater than 0.1μM, the promoting effect on rice plants was no longer significantly increased. After soaking seeds with 0.1g / L gibberellin, plant height, root length and root fresh weight increased by 11%, 11% and 19% respectively compared with the control, but the effect was not as significant as 0.1μM 3-methylpyrrolidine-2-carboxylic acid. Therefore, 3-methylpyrrolidine-2-carboxylic acid has the best growth-promoting effect on rice seedlings when the concentration is 0.1μM, and compared with gibberellin treatment, plant height, root length and root fresh weight increased significantly by 7%, 6% and 13% respectively. The above results show that 3-methylpyrrolidine-2-carboxylic acid can effectively promote the growth of rice seedlings.

[0039] The above experimental results have shown that 3-methylpyrrolidine-2-carboxylic acid as a rice seed soaking agent can promote the growth of rice, and 0.1μM 3-methylpyrrolidine-2-carboxylic acid has the best growth-promoting effect. Therefore, in order to further obtain the optimal concentration of 3-methylpyrrolidine-2-carboxylic acid for seed soaking, based on the above experiments, the concentration of 3-methylpyrrolidine-2-carboxylic acid was reduced to between 0.1μM and 0.4μM for experiments, and the plant height, root length and chlorophyll content of the seedlings were measured respectively.

[0040] Accurately cut 0.1g of the above rice leaves for determination of chlorophyll content. The samples were extracted with 10ml 95% ethanol in the dark for 24 hours, and 3 replicates were set for each treatment. The absorbance was measured at 645nm and 663nm using an ELISA reader, with 95% ethanol as a blank control, and the chlorophyll content was calculated using the modified formula of the Arnon method. The results are shown in Table 3.

[0041] Chl a =(12.71A 663 -2.59A 645 )×(v / m)

[0042] Chl b =(22.88A 645 -4.67A 663 )×(v / m)

[0043] Chl t =(8.04A663 +20.29A 645 )×(v / m)

[0044] In the formula, Chl a , Chl b , Chl t are the concentrations of chlorophyll a, b and total chlorophyll (mg / gFW); v is the volume of the extract (L); m is the weight of the leaves (g); A 663 , A 645 The absorbance values ​​are 663 and 645 nm respectively.

[0045] Table 3 Effects of different concentrations of 3-methylpyrrolidine-2-carboxylic acid (MPRO) soaking on the growth of rice seedlings

[0046]

[0047] The results showed that compared with the blank control, the plant height, root length, root fresh weight and chlorophyll content of rice plants increased to varying degrees under different concentrations of 3-methylpyrrolidine-2-carboxylic acid seed soaking treatment. After treatment with 0.1μM, 0.2μM and 0.4μM 3-methylpyrrolidine-2-carboxylic acid solution, the plant height increased significantly by 7%, 17% and 9%, the root length increased significantly by 11%, 29% and 23%, the root fresh weight increased significantly by 21%, 63% and 34%, and the chlorophyll content increased by 15%, 23% and 23%, respectively. After treatment with 0.1g / L gibberellin, the plant height and root length increased by 13% and 17%, the root fresh weight increased by 34%, and the chlorophyll content increased by 15%. In summary, when the concentration of 3-methylpyrrolidine-2-carboxylic acid was 0.2 μM, the effect on promoting rice root development and plant growth was the most significant, and compared with the 0.1 g / L gibberellin treatment, the root length and root fresh weight were significantly increased, increasing by 10% and 19%, respectively.

[0048] Example 3: Effect of 3-methylpyrrolidine-2-carboxylic acid on cucumber seed germination

[0049] Healthy, plump and uniform cucumber seeds (variety "Chuxia Qiuguan", Shandong Ningyang County Luming Seed Co., Ltd.) were selected and placed in a round culture dish. Clean water, 3-methylpyrrolidine-2-carboxylic acid with concentrations of 0.01, 0.1, 0.5 and 1 μM and 25 mL of 0.1 g / L gibberellin aqueous solution were added to each culture dish. Stir to completely immerse the seeds in the solution, soak the seeds in the dark at 4 ° C, and randomly select 18 cucumber seeds with tweezers after 72 hours. Arrange them in a 3×6 square culture dish covered with moist filter paper and place them in a 27 ° C culture room for germination culture. Each group of experiments was repeated three times. Wait for 3 days, measure and record the root length and number of lateral roots of the seeds. The results are shown in Table 4.

[0050] Table 4 Effects of different concentrations of 3-methylpyrrolidine-2-carboxylic acid (MPRO) on cucumber seed germination

[0051]

[0052] The results showed that the phenotype and biomass of cucumber seeds treated with 3-methylpyrrolidine-2-carboxylic acid were significantly different from those treated with water. Compared with the blank control, the root length of cucumber seedlings increased by 5%, 85%, 12% and 43% after treatment with 0.01μM, 0.1μM, 0.5μM and 1μM 3-methylpyrrolidine-2-carboxylic acid solution, respectively. Among them, the difference between 0.1μM and 1μM 3-methylpyrrolidine-2-carboxylic acid was significant, and the root length increased significantly by 66% after treatment with 0.1g / L gibberellin. When the cucumber seedlings treated with blank control, 0.01μM and 0.5μM 3-methylpyrrolidine-2-carboxylic acid solution had not yet grown lateral roots, the number of lateral roots of the seedlings treated with 0.1μM, 1μM 3-methylpyrrolidine-2-carboxylic acid and 0.1g / L gibberellin solution reached 8, 2 and 4 roots, respectively. The above results show that 3-methylpyrrolidine-2-carboxylic acid can effectively promote the occurrence and growth of cucumber young roots. 0.1 μM 3-methylpyrrolidine-2-carboxylic acid has the best effect on promoting cucumber seed germination, and the root length and lateral root number increase by 12% and 50% respectively compared with 0.1 g / L gibberellin treatment.

[0053] Example 4: Effect of 3-methylpyrrolidine-2-carboxylic acid on rooting of cucumber seedlings

[0054] Four layers of moist gauze were laid flat on the bottom of the culture box, and cucumber seeds with full shape and uniform size (variety "Chuxia Qiuguan", Shandong Ningyang County Luming Seed Co., Ltd.) were selected, disinfected with 75% ethanol, rinsed with distilled water, and evenly sprinkled on the gauze, and then covered with four layers of moist gauze to avoid light. After 24 hours of light protection in a 25℃ culture room, the germinated cucumber seeds were taken out and buried in a plastic pot (diameter 12cm) filled with moist (saturated water) soil, with a depth of 2-3cm, 5 seeds per pot, and placed in a 25℃ culture room (light intensity 200μMolm s') for cultivation. After 3 days, one strong seedling with fully expanded cotyledons was retained, and 25mL of 3-methylpyrrolidine-2-carboxylic acid and Yishibang (Syngenta) with concentrations of 0.01, 0.1, 0.25, 0.5 and 1μM were slowly irrigated along the base of the seedling stem, and 3 replicates were performed for each treatment. The light culture was continued in a 25℃ culture room. The plant height and true leaf growth of cucumber seedlings under different treatments were observed and recorded on the 6th and 12th days after treatment. On the 18th day, the plant height, the area of ​​the first true leaf, the area of ​​the second true leaf, the area of ​​the third true leaf, the whole plant fresh weight, the fresh weight of the aboveground part, the fresh weight of the underground part and the root length of the cucumber seedlings under different treatments were measured. The results are shown in Table 5.

[0055] Table 5 Effects of different concentrations of 3-methylpyrrolidine-2-carboxylic acid (MPRO) on the growth of cucumber seedlings

[0056]

[0057]

[0058] The results showed that the cucumber plants treated with 3-methylpyrrolidine-2-carboxylic acid solution had significantly different biomass and phenotypes compared with those treated with water. Compared with the blank control, the leaf area, plant height, root length and root fresh weight of cucumbers were improved to varying degrees after treatment with 3-methylpyrrolidine-2-carboxylic acid solution at five different concentrations, 0.01μM, 0.1μM, 0.25μM, 0.5μM and 1μM, among which 0.25μM 3-methylpyrrolidine-2-carboxylic acid had the best effect. Compared with the blank control, the first true leaf area of ​​cucumber seedlings treated with 0.25μM 3-methylpyrrolidine-2-carboxylic acid increased by 96%, 53% and 31% at 6, 12 and 18 days, respectively; the second true leaf area increased by 173% and 42% at 12 and 18 days, respectively; the third true leaf area increased by 193% at 18 days, the plant height increased by 15%, the root length increased by 50%, the whole plant fresh weight increased by 68%, and the root fresh weight increased by 97%. The results showed that 3-methylpyrrolidine-2-carboxylic acid can significantly promote the occurrence of complete root system and plant growth of cucumber, and the effect of promoting cucumber growth is best when the concentration is 0.25μM.

[0059] The above experiment determined that 0.25 μM 3-methylpyrrolidine-2-carboxylic acid had the best growth-promoting effect on cucumber, so 0.25 μM 3-methylpyrrolidine-2-carboxylic acid and Yishibang (diluted 1000 times) were used to treat cucumber seedlings, and their true leaf area, fresh weight of the aboveground part, and various indicators of the underground part were measured. The results are shown in Table 6.

[0060] Table 6 Effects of 3-methylpyrrolidine-2-carboxylic acid (MPRO) and Yishibang on the growth of cucumber seedlings

[0061]

[0062]

[0063] The results showed that 0.25μM 3-methylpyrrolidine-2-carboxylic acid solution had a significant growth-promoting effect on cucumber seedlings. Compared with the blank control, after treatment with 0.25μM 3-methylpyrrolidine-2-carboxylic acid, the first true leaf area of ​​cucumber increased by 50%, 54% and 38% on the 6th, 12th and 18th days, respectively; the second true leaf area increased by 180% and 46% on the 12th and 18th days, respectively; the third true leaf area increased by 210% on the 18th day, the plant height increased by 4%, the root length increased by 55%, the whole plant fresh weight increased by 70%, and the root fresh weight increased by 99%. In addition, compared with the blank control, the first true leaf area of ​​the cucumber seedlings treated with Yishibang increased by 29%, 11%, and 9% on the 6th, 12th, and 18th days, respectively; the second true leaf area increased by 84% and 1% on the 12th and 18th days, respectively; on the 18th day, the third true leaf area increased by 41%, the plant height increased by 1%, the root length increased by 23%, the whole plant fresh weight increased by 20%, and the root fresh weight increased by 31%. The results show that 3-methylpyrrolidine-2-carboxylic acid solution has a significant growth-promoting effect on cucumber seedlings, and under the same experimental conditions, its growth-promoting effect is better than Yishibang.

[0064] Example 5: Effect of 3-methylpyrrolidine-2-carboxylic acid on photosynthesis of cucumber seedlings

[0065] To further explore the mechanism of 3-methylpyrrolidine-2-carboxylic acid in promoting cucumber growth, the effect of 3-methylpyrrolidine-2-carboxylic acid treatment on photosynthesis of cucumber seedlings was studied. Following the above experiments, 0.25 μM 3-methylpyrrolidine-2-carboxylic acid and Yishibang (effective concentration diluted 1000 times, YSB) were used to treat cucumber seedlings, and the chlorophyll content and the comprehensive performance index of the photosystem PI of cucumber seedlings were measured at 6 days, 12 days and 18 days. ABS and PI total The effects of 3-methylpyrrolidine-2-carboxylic acid on the photosynthetic physiological mechanism of cucumber growth were investigated. The results are shown in Table 7.

[0066] Table 7 Effects of 3-methylpyrrolidine-2-carboxylic acid (MPRO) and Yishibang on photosynthesis of cucumber seedlings

[0067]

[0068]

[0069] The results showed that 3-methylpyrrolidine-2-carboxylic acid treatment significantly increased the chlorophyll content of cucumber leaves. Among them, the chlorophyll content of the first true leaf on the 6th day, the second true leaf on the 12th day, and the third true leaf on the 18th day was the most significant: compared with the blank control, on the 6th day after 3-methylpyrrolidine-2-carboxylic acid treatment, the chlorophyll a, chlorophyll b and total chlorophyll contents in the first true leaf of cucumber increased significantly by 18%, 14% and 17%, respectively, while the chlorophyll a, chlorophyll b and total chlorophyll contents after Yishibang treatment increased by 10%; on the 12th day, the second true leaf of cucumber increased by 14%, 17% and 17%, respectively. The contents of chlorophyll a, chlorophyll b and total chlorophyll in the true leaves increased significantly by 37%, 42% and 48%, respectively, while the contents of chlorophyll a, chlorophyll b and total chlorophyll after Yishibang treatment increased by 23%; on the 18th day, the contents of chlorophyll a, chlorophyll b and total chlorophyll in the third true leaf of cucumber increased significantly by 32%, 26% and 31%, respectively, while the contents of chlorophyll a, chlorophyll b and total chlorophyll after Yishibang treatment increased significantly by 19%, 13% and 18%, respectively. It can be seen that the application of 3-methylpyrrolidine-2-carboxylic acid can significantly increase the chlorophyll content of cucumber leaves, thereby improving the efficiency of leaves in capturing and utilizing light energy and promoting photosynthesis, and the promotion effect at a concentration of 0.25μM is better than that of Yishibang.

[0070] PI ABS Combines three independent parameters evaluated from the OJIP fluorescence induction curve: γ RC , Eo and It is usually used to quantify the overall performance of PSⅡ and represents the overall photosynthetic activity of PSⅡ. total It reflects the reduction ability from the electron donor side of PSⅡ to the electron acceptor side of PSI, which involves multiple electron transfer processes (Strasser, 2004). The results showed that the PI of leaves after treatment with 3-methylpyrrolidine-2-carboxylic acid ABS and PI total The PI of the first true leaf on the 6th day after treatment, the second true leaf on the 12th day after treatment, and the third true leaf on the 18th day after treatment were significantly higher than those of the control. ABS They increased by 5.2%, 17.7% and 10.7% respectively, and PI total increased by 2.0%, 42.7% and 44.8% respectively; and the PI of the leaves after Yishibang treatment ABS and PI totalThere was no significant difference compared with the control group. This indicates that 3-methylpyrrolidine-2-carboxylic acid improves the photochemical efficiency of PSⅡ in cucumber leaves, improves the ability of the PSⅠ receptor side to accept electrons and the photosynthetic activity of PSⅠ, thereby promoting the activity of the electron transport chain. This may be due to the increase in light-harvesting pigments in the leaves and the electrons entering photosynthesis, which in turn increases the efficiency of electron transfer and energy flow. Overall, the values ​​of various parameters in the first, second, and third true leaves of cucumbers gradually narrowed with the extension of the growth days after treatment, indicating that 3-methylpyrrolidine-2-carboxylic acid may play a major role in promoting the early stage of new leaf development, and its growth-promoting effect on cucumber seedlings is better than that of Yishibang.

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Claims

1. Application of 3-methylpyrrolidine-2-carboxylic acid in the preparation of plant growth promoters.

2. The use according to claim 1, characterized in that: The plants are selected from food crops and vegetables; the food crops are preferably rice, and the vegetables are preferably cucumbers.

3. Application of 3-methylpyrrolidine-2-carboxylic acid in promoting plant growth.

4. The use according to claim 3, characterized in that: The plants are selected from food crops and vegetables; the food crops are preferably rice, and the vegetables are preferably cucumbers.

5. The use according to any one of claims 3-4, characterized in that: Application of 3-methylpyrrolidine-2-carboxylic acid in promoting the growth of plant seedlings; preferably application of 3-methylpyrrolidine-2-carboxylic acid in promoting the growth of plant seedlings by root irrigation treatment.

6. The use according to any one of claims 3-4, characterized in that: 3-Methylpyrrolidine-2-carboxylic acid is used to promote the occurrence and growth of the root system of plant seedlings by soaking seeds.

7. A method for promoting plant growth, characterized in that: A 0.01-1 μM 3-methylpyrrolidine-2-carboxylic acid solution is applied to the target plant; the target plant is selected from food crops and vegetables; the food crop is preferably rice, and the vegetable is preferably cucumber.

8. The method according to claim 7, characterized in that Soaking seeds with a 3-methylpyrrolidine-2-carboxylic acid solution at a concentration of 0.01-1 μM can significantly promote rice seed germination and rice seedling growth.

9. The method according to claim 8, characterized in that The rice seeds are soaked in a 0.1-0.4 μM 3-methylpyrrolidine-2-carboxylic acid solution, preferably in a 0.1 μM 3-methylpyrrolidine-2-carboxylic acid solution to promote the germination of rice seeds, and in a 0.2 μM 3-methylpyrrolidine-2-carboxylic acid solution to promote the growth of rice seedlings.

10. The method according to claim 7, characterized in that Using a 3-methylpyrrolidine-2-carboxylic acid solution with a concentration of 0.01-1 μM to soak seeds can significantly promote cucumber seed germination and rice seedling growth; preferably, using a 0.1 μM 3-methylpyrrolidine-2-carboxylic acid solution to soak cucumber seeds to promote cucumber seed germination; using a 0.1-0.3 μM 3-methylpyrrolidine-2-carboxylic acid solution to treat cucumber soil-cultured seedlings by root irrigation to promote the growth of cucumber seedlings; further preferably, using a 0.25 μM 3-methylpyrrolidine-2-carboxylic acid solution to treat cucumber soil-cultured seedlings by root irrigation to promote the growth of cucumber seedlings.

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