3-methylpyrrolidine-2-carboxylic acid for use in promoting plant growth

Abstract

The application discloses application of 3-methylpyrrolidine-2-carboxylic acid to promoting growth of plants. The application discloses application of 3-methylpyrrolidine-2-carboxylic acid to preparing a plant growth promoter. It is found that 3-methylpyrrolidine-2-carboxylic acid can promote growth and development of plants when being used for seed soaking treatment and root irrigation treatment. The 3-methylpyrrolidine-2-carboxylic acid is convenient to use, and can solve problems in production that cannot be solved by traditional agriculture and save production cost. In addition, the 3-methylpyrrolidine-2-carboxylic acid is a metabolite with simple structure and exists in nature, belongs to alpha-amino acid, has high environmental and biological safety, and belongs to the category of green and efficient biochemistry pesticides.

Description

Technical Field

[0001] This 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 Technology

[0002] Plant growth and development not only require the supply of resources such as light, water, and nutrients, but are also regulated by growth substances. Plant growth substances mainly include two categories: plant hormones and plant growth regulators. Plant growth regulators are artificially synthesized or extracted compounds with the physiological activity of natural plant hormones. They 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, maturation and senescence, to promote or inhibit seed germination, plant growth, fruit ripening, flower and fruit preservation or thinning, improve plant immunity, help plants resist adverse environments, reduce diseases, increase crop yield, and improve crop quality. Due to their significant and efficient regulatory effects, they have been widely used in various aspects of grains, fruit trees, forestry, vegetables, and flowers. Currently, 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 significant role in regulating crop growth, solving many problems that traditional agronomic methods could not address, and making important contributions to my country's agricultural production and development. They have become one of the main measures for increasing agricultural yield, improving quality, and enhancing efficiency. However, plant growth regulators are a type of pesticide and also possess a certain degree of toxicity. Food safety issues caused by the indiscriminate and excessive use of plant growth regulators remain widespread, and international standards for residue limits of plant growth regulators are becoming increasingly stringent. Therefore, developing low-toxicity, highly effective, and environmentally friendly plant growth regulators is of paramount importance.

[0004] 3-Methylpyrrolidine-2-carboxylic acid, with the molecular formula C6H 11NO2, with a molecular weight of 129 g / mol, is a colorless crystal. The earliest report of this compound was in 1964, when 3-methylpyrrolidine-2-carboxylic acid was first synthesized chemically. Subsequent activity studies revealed that this compound inhibits the synthesis of actinomycin in *Streptomyces antibioticus*, and that 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., one of the major saprophytic plant pathogenic fungi widely distributed in nature. This is also the first discovery that a naturally occurring wild-type microorganism can produce 3-methylpyrrolidine-2-carboxylic acid in a relatively high quantity. We studied its plant immune-inducing activity and found that it can induce plant immune responses, thereby resisting fungal, bacterial, and viral diseases; at the same time, it can induce plant resistance to high and low temperature stress 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 precisely the innovation of this patent. Summary of the Invention

[0005] The purpose of this invention is to address the above-mentioned shortcomings of the prior art by providing an application of 3-methylpyrrolidine-2-carboxylic acid as a growth regulator to promote plant growth.

[0006] The objective of this 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 root development and growth of plant seedlings by soaking seeds.

[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 mentioned are selected from grain crops and vegetables. Rice is the preferred grain crop, and cucumber is the preferred vegetable.

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

[0012]

[0013] Existing research on 3-methylpyrrolidine-2-carboxylic acid has not included reports on its application as a plant growth regulator. 3-methylpyrrolidine-2-carboxylic acid has shown good performance in experiments promoting plant growth, demonstrating its ability to boost plant growth and increase yield. Detailed information and implementation methods are as follows:

[0014] A method for promoting plant growth involves applying a 0.01-1 μM solution of 3-methylpyrrolidine-2-carboxylic acid to a target plant; the target plant is selected from grain crops and vegetables; the grain 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, is described. The method involves treating rice seeds by soaking them at a concentration range of 0.01-1 μM, which significantly promotes rice seed germination. In particular, at a concentration of 0.1 μM, the root length of rice increased by 57% compared with the blank control.

[0016] As a preferred embodiment of the present invention, a method for promoting rice seedling growth using 3-methylpyrrolidine-2-carboxylic acid involves treating rice seeds with a concentration ranging from 0.01 to 1 μM by soaking, which significantly promotes rice seedling growth. To further screen the optimal concentration for seed soaking, based on the above experiments, the concentration of 3-methylpyrrolidine-2-carboxylic acid was reduced to between 0.1 μM and 0.4 μM. At a concentration of 0.2 μM, the effect on promoting root development and plant growth in rice was most significant, with plant height, root length, and root fresh weight increasing by 17%, 29%, and 63%, respectively, compared to the blank control group.

[0017] As a preferred embodiment of the present invention, the method of using 3-methylpyrrolidine-2-carboxylic acid to promote rooting of cucumber seedlings, wherein cucumber seeds are treated by soaking in a concentration range of 0.01-1 μM, which can significantly promote the germination of cucumber seeds; especially at a concentration of 0.1 μM, the root length of cucumber seedlings increased by 85% compared with the blank control.

[0018] As a preferred embodiment of the present invention, the method of using 3-methylpyrrolidine-2-carboxylic acid to promote the growth of cucumber seedlings, when applied as a root irrigation at a concentration of 0.01-1 μM, significantly promotes the growth of cucumber seedlings. Specifically, at a concentration of 0.25 μM, compared with the blank control group, the area of ​​the first, second, and third true leaves, plant height, root length, whole plant fresh weight, and root fresh weight increased by 38%, 46%, 210%, 4%, 55%, 70%, and 99% respectively after 18 days. Furthermore, the chlorophyll a, chlorophyll b, total chlorophyll content, and PI content in the third true leaf after 18 days were also significantly increased. ABS and PItotal They increased significantly by 32%, 26%, 31%, 10.7%, and 44.8%, respectively.

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

[0020] 3-Methylpyrrolidine-2-carboxylic acid is a natural product with a simple structure, making it easy to produce industrially. Since this 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] This invention discovers that 3-methylpyrrolidine-2-carboxylic acid can effectively promote plant growth through seed soaking and root irrigation. At a concentration of 0.1 μM, seed soaking promotes rice seed germination and significantly increases the root and stem growth of rice seedlings. At a concentration of 0.2 μM, seed soaking promotes rice seedling growth and significantly increases seedling height and root fresh weight. At a concentration of 0.1 μM, seed soaking promotes cucumber seed germination and significantly increases the root length of cucumber seedlings. At a concentration of 0.25 μM, root irrigation of soil-grown cucumber seedlings promotes cucumber seedling growth and significantly increases leaf area, plant height, root length, fresh weight, chlorophyll content, and the photosystem II comprehensive performance index of cucumber seedlings.

[0022] 3-Methylpyrrolidine-2-carboxylic acid is a natural product, used in low amounts, and is environmentally friendly. It has a significant promoting effect on plant growth, making it a green and efficient bio-based plant growth regulator. This indicates the utilization value and application prospects of this type of substance in agricultural production.

[0023] This invention discovers that 3-methylpyrrolidine-2-carboxylic acid (3-MCPA) can promote plant growth and development through seed soaking and root irrigation. 3-MCPA is easy to use, solving production problems that traditional agronomic methods cannot address, and saving production costs. Furthermore, because 3-MCPA is a naturally occurring, structurally simple metabolite belonging to the α-amino acid family, it exhibits high environmental and biological safety, falling into the category of green and highly efficient biochemical pesticides. Attached Figure Description

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

[0025] Figure 2 Effects of different concentrations of 3-methylpyrrolidine-2-carboxylic acid soaking on rice seedling growth.

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

[0027] Figure 4 Effects of different concentrations of 3-methylpyrrolidine-2-carboxylic acid drenching on cucumber seedling growth. Detailed Implementation

[0028] The inventors conducted research on the bioactivity, applicability, and crop safety of 3-methylpyrrolidine-2-carboxylic acid, discovering that this substance also has a unique role in regulating crop growth and possesses advantages such as environmental friendliness, wide applicability, and safe use. It is a natural plant growth regulator with the potential to be developed into a biopesticide. The essential features of this invention can be seen from the following embodiments and examples, but these should not be considered as any limitation on the invention.

[0029] Example 1: Effect of 3-methylpyrrolidine-2-carboxylic acid soaking on rice seed germination

[0030] Rice seeds (variety "Dengliangyou 2108") were rinsed with distilled water, disinfected with 75% alcohol for 3 minutes, rinsed three times with distilled water, and then disinfected with NaClO (5%) for about 10 minutes. After removal, the seeds were rinsed with distilled water, and then the residual moisture on the seed surface was absorbed with clean filter paper until the surface was dry. 4 g of healthy, plump, and uniform seeds were selected and placed in 50 mL centrifuge tubes. Each tube was first filled with water, 0.01, 0.1, and 1 μM of 3-methylpyrrolidine-2-carboxylic acid, and 8 mL of 0.1 g / L (260 μM, recommended production concentration) gibberellin aqueous solution. The mixture was stirred to completely submerge the seeds in the solution. After soaking at room temperature for 48 hours, the seeds were germinated directly without rinsing. Each experiment was repeated in triplicate. In each replicate, 30 rice seeds were randomly selected with tweezers and placed in a petri dish pre-lined with moistened filter paper. The plates were then placed in a 28℃ incubator for germination. Three days later, the seed germination rate, shoot length, and root length were measured and recorded.

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

[0032]

[0033] Table 1 shows that treatment with 0.01 μM, 0.1 μM, and 1 μM 3-methylpyrrolidine-2-carboxylic acid solutions increased the stem and root lengths of rice seedlings to varying degrees. Compared with the control, soaking in 0.01 μM, 0.1 μM, and 1 μM 3-methylpyrrolidine-2-carboxylic acid solutions significantly increased the seed germination rate by 5%, 4%, and 5%, respectively, and the root length by 14%, 57%, and 29%, respectively. At 0.1 μM and 1 μM concentrations, the stem length increased significantly by 40% and 20%, respectively. When the concentration of 3-methylpyrrolidine-2-carboxylic acid exceeded 0.1 μM, the promoting effect on rice seedlings no longer increased significantly. Soaking in 0.1 g / L gibberellin solution increased the seed germination rate by 5% and significantly increased the stem and root lengths by 60% and 29%, respectively, compared with the control. The results showed that treatment with 0.1 μM 3-methylpyrrolidine-2-carboxylic acid (3-MCCA) was the most effective in promoting root and stem growth in rice seedlings. However, in promoting stem growth, 0.1 μM 3-MCCA was slightly less effective than 0.1 g / L gibberellin (approximately 260 μM); while in promoting root growth, 3-MCCA performed significantly better than gibberellin. Considering that excessively rapid stem growth in rice seedlings can easily lead to tall, thin seedlings, which is not conducive to robust seedling development, root development is more important than stem promotion during the rice seedling stage. Therefore, 3-methylpyrrolidine-2-carboxylic acid has a better seedling-strengthening effect and greater application potential than gibberellin.

[0034] Example 2: Effects of 3-methylpyrrolidine-2-carboxylic acid seed soaking on rice seedling growth

[0035] Rinse the rice seeds (variety "Dengliangyou 2108") with distilled water, disinfect them with 75% alcohol for 3 minutes, rinse them three times with distilled water, and then disinfect them with NaClO (5%) for about 10 minutes. After removing them, rinse them with distilled water and then use clean filter paper to absorb the residual moisture on the seed surface until the surface is dry. Select 4 g of healthy, plump and uniform seeds and place them in 50 mL centrifuge tubes. Add 8 mL of water, 0.01, 0.1 and 1 μM 3-methylpyrrolidine-2-carboxylic acid and 0.1 g / L gibberellin aqueous solution to each tube. Stir to completely submerge the seeds in the solution. After soaking at room temperature for 5 days, select 100 rice seeds of the same germination state and sow them evenly in rice seedling trays, cover them with soil, and place the seedling trays in a 28 ℃ incubation room. When the rice seedlings grow to the three-leaf stage, remove the whole plant and measure the plant height, root length and chlorophyll content of the seedlings. The results are shown in Table 2.

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

[0037]

[0038] The results showed that rice seeds treated with 3-methylpyrrolidine-2-carboxylic acid (3-MCPA) exhibited significant differences in phenotype and biomass compared to those treated with plain water. Treatment with 3-MCPA solutions at three different concentrations (0.01 μM, 0.1 μM, and 1 μM) increased plant height, root length, and root fresh weight to varying degrees. Compared to the control, soaking in 0.01 μM, 0.1 μM, and 1 μM 3-MCPA solutions significantly increased plant height by 7%, 19%, and 10%, respectively; root length by 11%, 22%, and 12%, respectively; and root fresh weight by 12%, 35%, and 19%, respectively. When the concentration of 3-MCPA exceeded 0.1 μM, the promoting effect on rice plants no longer significantly increased. After soaking seeds in 0.1 g / L gibberellin, compared with the control, plant height, root length, and root fresh weight increased by 11%, 11%, and 19%, respectively, but the effect was not as significant as that of 0.1 μM 3-methylpyrrolidine-2-carboxylic acid. Therefore, a concentration of 0.1 μM of 3-methylpyrrolidine-2-carboxylic acid showed the best growth-promoting effect on rice seedlings, and compared with gibberellin treatment, plant height, root length, and root fresh weight increased significantly by 7%, 6%, and 13%, respectively. These results indicate 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 (3-MPA) can promote rice growth when used as a seed soaking agent, and the 0.1 μM concentration of 3-MPA exhibits the best growth-promoting effect. Therefore, to further determine the optimal concentration of 3-MPA for seed soaking, based on the above experiments, the concentration of 3-MPA was reduced to between 0.1 μM and 0.4 μM, and the seedling height, root length, and chlorophyll content were measured.

[0040] Accurately cut 0.1 g of the above-mentioned rice leaves for chlorophyll content determination. The samples were extracted with 10 ml of 95% ethanol in the dark for 24 hours, with three replicates per treatment group. Absorbance was measured at 645 nm and 663 nm using a microplate reader, with 95% ethanol as a blank control. Chlorophyll content was calculated using the modified Arnon method. 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 = (8.04A) 663 +20.29A 645 ) × (v / m)

[0044] In the formula, Chl a Chl b Chl t These represent the concentrations of chlorophyll a, b, and total chlorophyll (mg / gFW); v is the extraction liquid volume (L); m is the mass of the leaf taken (g); A 663 A 645 The absorbance values ​​are 663 nm and 645 nm, respectively.

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

[0046]

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

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

[0049] Healthy, plump, and uniformly sized cucumber seeds (variety "Chuxia Qiuguan," Shandong Ningyang Luming Seed Co., Ltd.) were selected and placed in round petri dishes. Each dish was then filled with 25 mL of water, 0.01, 0.1, 0.5, and 1 μM solutions of 3-methylpyrrolidine-2-carboxylic acid, and 0.1 g / L gibberellin. The seeds were stirred to ensure complete immersion in the solutions and soaked in the dark at 4℃ for 72 hours. After 72 hours, 18 cucumber seeds were randomly selected using tweezers and arranged in a 3 × 6 pattern in a square petri dish lined with moistened filter paper. These were then placed in a 27℃ incubator for germination. Each experiment was repeated in triplicate. After 3 days, the root length and number of lateral roots were measured and recorded. 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 cucumber seeds treated with 3-methylpyrrolidine-2-carboxylic acid (3-MPA) exhibited significant differences in phenotype and biomass compared to those treated with plain water. Compared to the control, cucumber seedling root length increased by 5%, 85%, 12%, and 43% after treatment with 0.01 μM, 0.1 μM, 0.5 μM, and 1 μM 3-MPA solutions, respectively. The differences were particularly significant with 0.1 μM and 1 μM 3-MPA, and the root length increased significantly by 66% after treatment with 0.1 g / L gibberellin. Before lateral roots developed in the control, 0.01 μM, and 0.5 μM 3-MPA solutions, the seedlings treated with 0.1 μM, 1 μM 3-MPA, and 0.1 g / L gibberellin solutions had developed 8, 2, and 4 lateral roots, respectively. The results above indicate that 3-methylpyrrolidine-2-carboxylic acid can effectively promote the occurrence and growth of cucumber seedlings. 0.1 μM 3-methylpyrrolidine-2-carboxylic acid has the best effect on promoting cucumber seed germination, and compared with the 0.1 g / L gibberellin treatment, the root length and the number of lateral roots increased by 12% and 50%, respectively.

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

[0054] Four layers of moist gauze were laid flat at the bottom of the culture box. Plump, uniformly sized cucumber seeds (variety "Chuxia Qiuguan," Shandong Ningyang Luming Seed Co., Ltd.) were selected, disinfected with 75% ethanol, rinsed with distilled water, and evenly scattered on the gauze. The box was then covered with four more layers of moist gauze to protect from light. After 24 hours of light protection in a 25°C culture room, the germinated cucumber seeds were removed and buried in plastic pots (12 cm in diameter) filled with moist (saturated) soil at a depth of 2-3 cm, with 5 seeds per pot. These pots were then placed in a 25°C culture room (light intensity 200 μMolm s'). After 3 days, one robust seedling with fully expanded cotyledons was retained. The seedling was then slowly irrigated along its base with 25 mL of 0.01, 0.1, 0.25, 0.5, and 1 μM 3-methylpyrrolidine-2-carboxylic acid and Syngenta (Essential Power Injection), respectively. Each treatment was replicated in triplicate. The cucumber seedlings were cultured under light at 25 ℃. Plant height and true leaf growth were observed and recorded on days 6 and 12 after treatment. On day 18, plant height, area of ​​the first, second, and third true leaves, whole plant fresh weight, above-ground fresh weight, underground fresh weight, and root length were measured for each treatment. 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] The results showed that cucumber plants treated with 3-methylpyrrolidine-2-carboxylic acid solution exhibited significant differences in biomass and phenotype compared to those treated with plain water. Compared to the control, treatment with five different concentrations of 3-methylpyrrolidine-2-carboxylic acid solution (0.01 μM, 0.1 μM, 0.25 μM, 0.5 μM, and 1 μM) increased various indicators of cucumber growth, including leaf area, plant height, root length, and root fresh weight, with the 0.25 μM solution showing the best effect. Compared with the control group, seedlings treated with 0.25 μM 3-methylpyrrolidine-2-carboxylic acid showed increased first true leaf area by 96%, 53%, and 31% at 6, 12, and 18 days, respectively; second true leaf area by 173% and 42% at 12 and 18 days, respectively; and third true leaf area by 193% at 18 days. Plant height increased by 15%, root length by 50%, whole plant fresh weight by 68%, and root fresh weight by 97%. These results indicate that 3-methylpyrrolidine-2-carboxylic acid significantly promotes the development of a complete root system and plant growth in cucumber, with the optimal concentration of 0.25 μM showing the best growth-promoting effect.

[0058] The above experiments determined that 0.25 μM 3-methylpyrrolidine-2-carboxylic acid had the best growth-promoting effect on cucumber. Therefore, 0.25 μM 3-methylpyrrolidine-2-carboxylic acid and Yishibang (diluted 1000 times) were used to treat cucumber seedlings, and the true leaf area, aboveground fresh weight, and various biomass indicators of the underground parts were measured. The results are shown in Table 6.

[0059] Table 6. Effects of 3-methylpyrrolidine-2-carboxylic acid (MPRO) and Epclusa on cucumber seedling growth

[0060]

[0061] The results showed that 0.25 μM 3-methylpyrrolidine-2-carboxylic acid solution had a significant growth-promoting effect on cucumber seedlings. Compared with the blank control, after treatment with 0.25 μM 3-methylpyrrolidine-2-carboxylic acid, the area of ​​the first true leaf of cucumber increased by 50%, 54%, and 38% on days 6, 12, and 18, respectively; the area of ​​the second true leaf increased by 180% and 46% on days 12 and 18, respectively; the area of ​​the third true leaf increased by 210% on day 18; plant height increased by 4%; root length increased by 55%; whole plant fresh weight increased by 70%; and root fresh weight increased by 99%. Furthermore, compared with the control group, the area of ​​the first true leaf of cucumber seedlings treated with Yishibang increased by 29%, 11%, and 9% on days 6, 12, and 18, respectively; the area of ​​the second true leaf increased by 84% and 1% on days 12 and 18, respectively; and the area of ​​the third true leaf increased by 41% on day 18. Plant height also increased by 1%, root length by 23%, overall plant fresh weight by 20%, and root fresh weight by 31%. These results indicate 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 superior to that of Yishibang.

[0062] Example 5: Effects of 3-methylpyrrolidine-2-carboxylic acid on photosynthesis in cucumber seedlings

[0063] To further explore the mechanism by which 3-methylpyrrolidine-2-carboxylic acid promotes cucumber growth, the effects of 3-methylpyrrolidine-2-carboxylic acid treatment on the photosynthesis of cucumber seedlings were studied. Following the previous experiments, cucumber seedlings were treated with 0.25 μM 3-methylpyrrolidine-2-carboxylic acid and YSB (effective concentration diluted 1000 times). The chlorophyll content and photosynthetic index (PI) of the cucumber seedling leaves were measured at 6, 12, and 18 days. ABS and PI total The study investigated the photosynthetic physiological mechanism by which 3-methylpyrrolidine-2-carboxylic acid promotes cucumber growth. The results are shown in Table 7.

[0064] Table 7 Effects of 3-methylpyrrolidine-2-carboxylic acid (MPRO) and Epclusa on photosynthesis in cucumber seedlings

[0065]

[0066] The results showed that 3-methylpyrrolidine-2-carboxylic acid treatment significantly increased the chlorophyll content of cucumber leaves. The most significant differences were observed in the chlorophyll content of the first true leaf on day 6, the second true leaf on day 12, and the third true leaf on day 18: compared to the control, on day 6 after 3-methylpyrrolidine-2-carboxylic acid treatment, the contents of chlorophyll a, chlorophyll b, and total chlorophyll in the first true leaf of cucumber were significantly increased by 18%, 14%, and 17%, respectively, while the contents of chlorophyll a, chlorophyll b, and total chlorophyll in the third true leaf after treatment with 3-methylpyrrolidine-2-carboxylic acid were all significantly increased by 10%; on day 12, the contents of the second true leaf of cucumber were significantly increased by 10%. The contents of chlorophyll a, chlorophyll b, and total chlorophyll in true leaves increased significantly by 37%, 42%, and 48%, respectively, while the contents of chlorophyll a, chlorophyll b, and total chlorophyll increased by 23% after treatment with Yishibang. On day 18, 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 increased significantly by 19%, 13%, and 18% after treatment with Yishibang. Therefore, the application of 3-methylpyrrolidine-2-carboxylic acid can significantly increase the chlorophyll content of cucumber leaves, thereby improving the efficiency of light energy capture and utilization, promoting photosynthesis, and the promoting effect at a concentration of 0.25 μM is superior to that of Yishibang.

[0067] PI ABS It combines three independent parameters for evaluation using OJIP fluorescence induction curves: PI is typically used to quantify the overall performance of PSII, representing its overall photosynthetic activity. total This reflects the reduction capacity from the PSII electron donor side to the PSI electron acceptor side, which involves multiple electron transport processes (Strasser, 2004). The results indicate that the PI in leaves treated with 3-methylpyrrolidine-2-carboxylic acid... ABS and PI total All were significantly higher than the control. The PI values ​​were highest at the first true leaf on day 6, the second true leaf on day 12, and the third true leaf on day 18 after treatment. ABS They rose by 5.2%, 17.7%, and 10.7% respectively, PI total The PI of the leaves treated with Yishibang increased by 2.0%, 42.7%, and 44.8% respectively; while the PI of the leaves treated with Yishibang increased. ABS and PI totalThere was no significant difference compared to the control group. This indicates that 3-methylpyrrolidine-2-carboxylic acid improved the photochemical efficiency of PSII in cucumber leaves, enhanced the electron-accepting capacity of PSⅠ on the receptor side, and increased 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 and electrons entering photosynthesis in the leaves, leading to increased efficiency in electron transport and energy flow. Overall, the differences between the treatment groups and the control group in the parameters of the first, second, and third true leaves of cucumber gradually narrowed with the extension of the number of days of growth after treatment, indicating that 3-methylpyrrolidine-2-carboxylic acid may play a major promoting role in the early stage of new leaf development, and its growth-promoting effect on cucumber seedlings is superior to that of Yishibang.

[0068] References:

[0069] [1] Chen Shiguo, Wang He, Wang Liangsheng, Fang Wanping, Guo Aiping. Application of 3-methylpyrrolidine-2-carboxylic acid as a plant immune inducer. Chinese Invention Patent, ZL202210737446.7, issued on November 15, 2024.

[0070] [2]Katz, E., Krapohl, N., Mauger, A., Weissbach, H., T Yoshida, T.Kinetics of 3-methylproline inhibition of actinomycin biosynthesis. Arch.Biochem. Biophys. 1968, 128, 534-553.

[0071] [3]Mauger, A., Irreverre, F., Witkop, B. The Stereochemistry of 3-Methylproline. J. Am. Chem. Soc. 1966, 88, 2019-2024.

[0072] [4]Yoshida, Y., Mauger, A., Witkop, B., Katz, E. 148th National Meeting of the American Chemical Society. Chicago. 1964.

[0073] [5]Yoshida, Y., Mauger A., Weissbach, H., Katz, E. Effect ofstructural and stereochemical methylproline isomers on actinomycinbiosynthesis. J. Bacteriol. 1968, 95, 952-958.

[0074] [6] Strasser, R.J., Tsimilli-Michael, M., Srivastava, A., 2004.Analysis of the Chlorophyll a Fluorescence Transient. In: Papageorgiou, G.C.,Govindjee, A.J. (Eds.), Chlorophyll Fluorescence: A Signature ofPhotosynthesis. Kluwer Academic Publishers Press, Netherlands, pp. 321–362.

Claims

The application of 1,3-methylpyrrolidine-2-carboxylic acid in the preparation of plant growth promoters, wherein the plant is rice or cucumber. Application of 2,3-methylpyrrolidine-2-carboxylic acid in promoting plant growth, wherein the plant is rice or cucumber.

3. The application according to claim 2, characterized in that, Application of 3-methylpyrrolidine-2-carboxylic acid in promoting the growth of plant seedlings.

4. The application according to any one of claims 2-3, characterized in that, Application of 3-methylpyrrolidine-2-carboxylic acid to promote seedling growth through root irrigation.

5. The application according to any one of claims 2-3, characterized in that, 3-Methylpyrrolidine-2-carboxylic acid is used to promote the development and growth of plant seedling roots through seed soaking.

6. A method for promoting plant growth, characterized in that, Apply a 0.01-1 μM solution of 3-methylpyrrolidine-2-carboxylic acid to the target plant; the target plant is rice or cucumber.

7. The method according to claim 6, characterized in that, Soaking seeds in a 0.01-1 μM solution of 3-methylpyrrolidine-2-carboxylic acid can significantly promote rice seed germination and seedling growth.

8. The method according to claim 7, characterized in that, Rice seeds were soaked in a 0.1-0.4 μM solution of 3-methylpyrrolidine-2-carboxylic acid.

9. The method according to claim 7, characterized in that, Rice seeds were soaked in a 0.1 μM 3-methylpyrrolidine-2-carboxylic acid solution to promote seed germination, and rice seedlings were soaked in a 0.2 μM 3-methylpyrrolidine-2-carboxylic acid solution to promote seedling growth.

10. The method according to claim 6, characterized in that, Soaking seeds in a 0.01-1 μM solution of 3-methylpyrrolidine-2-carboxylic acid can significantly promote cucumber seed germination and seedling growth.

11. The method according to claim 10, characterized in that, Cucumber seeds were soaked in a 0.1 μM 3-methylpyrrolidine-2-carboxylic acid solution to promote seed germination. Cucumber seedlings grown in soil were treated with a 0.1-0.3 μM 3-methylpyrrolidine-2-carboxylic acid solution by root irrigation to promote seedling growth.

12. The method according to claim 11, characterized in that, Cucumber seedlings grown in soil were treated with a 0.25 μM solution of 3-methylpyrrolidine-2-carboxylic acid by root irrigation to promote seedling growth.

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