Plant growth regulator and application thereof in promoting growth and coloring of eggplant under high temperature stress

Abstract

The application discloses a plant growth regulator and application thereof in promoting growth and coloring of eggplants under high-temperature stress, and belongs to the technical field of plant growth regulators. Methyl jasmonate and rhamnolipid are combined as active components of the plant growth regulator, which can effectively relieve the growth inhibition of eggplants under high-temperature stress, and synergistically improve the anthocyanin content in the pericarp of eggplants, significantly improve the coloring effect of eggplant fruits under high-temperature stress, and improve the fruit quality. The application adds a synergistic component on the basis of the active components; the synergistic component comprises potassium dihydrogen phosphate, calcium chloride, zinc sulfate and boric acid, and can further strengthen the active components from the aspects of energy and osmotic regulation, calcium signal and membrane stability, antioxidant enzyme activity and photosynthetic protection, cell wall integrity and sugar transport, so as to synergistically improve the heat tolerance of plants, promote anthocyanin accumulation of fruits and improve the coloring performance of fruit surfaces.

Description

Technical Field

[0001] This invention relates to the field of plant growth regulator technology, specifically to a plant growth regulator and its application in promoting the growth and coloring of eggplant under high temperature stress. Background Technology

[0002] eggplant( Solanum melongena Eggplant (L.) belongs to the genus Solanum in the family Solanaceae. It is an important vegetable crop in both greenhouse and open-field cultivation, and its yield and commercial quality are highly sensitive to environmental temperature conditions. Eggplant is a typical warm-season crop, with an optimal growth temperature of 20–30℃. When the environmental temperature is consistently higher than its optimal growth range, the plant's physiological metabolic activities will be significantly affected, leading to abnormal growth and development and a decline in fruit quality.

[0003] Under high-temperature stress, the photosynthetic efficiency of eggplant plants typically decreases, and the stomatal regulation function of leaves is inhibited, leading to a decline in carbon assimilation capacity. Simultaneously, increased respiration results in increased energy consumption, thus affecting nutrient accumulation and organ growth. Furthermore, high temperatures can affect flower development and pollen viability, increasing flower and fruit drop and reducing fruit set rate, thereby impacting yield stability. On the other hand, high temperatures significantly affect the coloring process of eggplant fruits. The purple color of eggplant peel mainly originates from the accumulation of anthocyanin pigments, and the biosynthesis of anthocyanins is highly sensitive to temperature changes. When temperatures are too high, the activity of enzymes related to anthocyanin synthesis decreases, and the expression of related genes is inhibited, leading to reduced anthocyanin accumulation. This results in uneven peel coloring, lighter coloring, or whitening, severely affecting the commercial appearance and market value of eggplants.

[0004] Therefore, in greenhouse cultivation or high-temperature summer environments, how to mitigate the adverse effects of high temperatures on eggplant plant growth and fruit coloring, improve eggplant's resistance to high temperatures, and maintain good fruit quality has become a pressing technical problem to be solved in the field of eggplant cultivation and quality control. Summary of the Invention

[0005] In view of the above-mentioned prior art, the purpose of this invention is to provide a plant growth regulator and its application in promoting the growth and coloring of eggplant under high temperature stress.

[0006] Specifically, the present invention relates to the following technical solutions:

[0007] In a first aspect, the present invention provides a plant growth regulator, wherein the active component of the plant growth regulator is composed of methyl jasmonate (MeJA) and rhamnolipid;

[0008] The concentration of methyl jasmonate in the plant growth regulator is 100-300 μM, and the volume concentration of rhamnolipin in the plant growth regulator is 0.05-0.15%.

[0009] Preferably, the concentration of methyl jasmonate in the plant growth regulator is 200 μM, and the volume concentration of rhamnolipin in the plant growth regulator is 0.1%.

[0010] Furthermore, the plant growth regulator may also contain a synergistic component, which is selected from one or more of potassium dihydrogen phosphate, calcium chloride, zinc sulfate, or boric acid.

[0011] Preferably, the concentration of potassium dihydrogen phosphate in the plant growth regulator is 1.5-4.5 g / L, the concentration of calcium chloride in the plant growth regulator is 5-15 mmol / L, the concentration of zinc sulfate in the plant growth regulator is 0.5-1.5 g / L, and the concentration of boric acid in the plant growth regulator is 1.0-3.0 g / L.

[0012] In some preferred embodiments of the present invention, the plant growth regulator comprises: an active component and a synergistic component;

[0013] The active components consist of methyl jasmonic acid and rhamnolipid; the concentration of methyl jasmonic acid in the plant growth regulator is 200 μM, and the volume concentration of rhamnolipid in the plant growth regulator is 0.1%.

[0014] The synergistic component consists of potassium dihydrogen phosphate, zinc sulfate, and boric acid; the concentration of potassium dihydrogen phosphate in the plant growth regulator is 3.0 g / L, the concentration of zinc sulfate in the plant growth regulator is 1.0 g / L, and the concentration of boric acid in the plant growth regulator is 2.0 g / L.

[0015] In a second aspect, the present invention provides the application of the above-mentioned plant growth regulator in promoting fruit coloring in eggplant under high temperature stress.

[0016] In the above applications, the temperature of the high-temperature stress is greater than or equal to 35°C.

[0017] The application method for promoting fruit coloring in eggplants under high temperature stress is as follows: before or during the occurrence of high temperature stress, spray the entire eggplant plant that has entered the full flowering stage with the above-mentioned plant growth regulator.

[0018] A third aspect of the present invention provides the application of the above-mentioned plant growth regulator in promoting the growth of eggplant under high temperature stress.

[0019] In the above applications, the temperature of the high-temperature stress is greater than or equal to 35°C.

[0020] The beneficial effects of this invention are:

[0021] (1) The present invention found that the combination of methyl jasmonate and rhamnolipid as active components of plant growth regulators can effectively alleviate the growth inhibition of eggplant under high temperature stress, synergistically increase the anthocyanin content in eggplant pericarp, significantly improve the coloring effect of eggplant fruit under high temperature stress, and improve fruit quality. The possible mechanism of action of the two is speculated to be: methyl jasmonate activates the JA signaling pathway, relieves the inhibition of anthocyanin synthesis and stress-related transcription factors by JAZ, enhances antioxidant capacity, membrane stability and anthocyanin biosynthesis under heat stress, thereby promoting the recovery of vegetative growth and fruit coloring of eggplant under high temperature conditions; rhamnolipid reduces the interfacial tension of the leaf surface, improves the wetting and spreading ability of the spray solution on the cuticle of leaves and fruits, and enhances the transmission efficiency of methyl jasmonate into the plant tissue, so that it can more effectively activate the JA signaling pathway. Therefore, rhamnolipin not only plays a separate role in stress induction in this invention, but also forms a synergistic effect with methyl jasmonate at the molecular delivery level, thereby significantly improving the overall regulatory effect. When the two are used together, rhamnolipin improves the delivery efficiency of methyl jasmonate and enhances the stress front response, while methyl jasmonate further amplifies the output of heat resistance and color promotion signals. Therefore, it has a synergistic effect in promoting eggplant growth and fruit coloring under high temperature.

[0022] (2) In order to further improve the effect of plant growth regulators, the present invention adds synergistic components to the active components; the synergistic components include one or more of potassium dihydrogen phosphate, calcium chloride, zinc sulfate and boric acid, which can further enhance the active components from the aspects of energy and osmotic regulation, calcium signal and membrane stability, antioxidant enzyme activity and photosynthetic protection, cell wall integrity and sugar transport, maintain ion homeostasis under high temperature conditions, membrane system integrity, carbon assimilation and transport of assimilates to fruit, thereby synergistically improving plant heat resistance, promoting anthocyanin accumulation in fruit and improving fruit coloring. Attached Figure Description

[0023] Figure 1 The coloring of eggplant fruits two weeks after spraying plant growth regulators in Experiment Example 2 of this invention.

[0024] Figure 2 The results of the determination of the relative anthocyanin content in eggplant peel two weeks after spraying the plant growth regulator in Experiment Example 2 of this invention. Detailed Implementation

[0025] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0026] To enable those skilled in the art to more clearly understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to specific embodiments. If specific experimental conditions are not specified in the embodiments, they are generally based on conventional conditions or conditions recommended by the reagent company; the reagents, consumables, etc. used in the following embodiments, unless otherwise specified, can be obtained commercially. Wherein:

[0027] Methyl jasmonate, CAS No.: 39924-52-2; rhamnolipin was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; trade name: rhamnolipin, product number: R916936-10g.

[0028] Example 1: Preparation of plant growth regulators

[0029] The plant growth regulator prepared in this embodiment contains only the active component, which consists of methyl jasmonate and rhamnolipid; the preparation method is as follows:

[0030] Plant growth regulators were prepared by dissolving methyl jasmonate and rhamnolipin in water to achieve a concentration of 200 μM for methyl jasmonate and a volume concentration of 0.1% for rhamnolipin.

[0031] Example 2: Preparation of plant growth regulators

[0032] The plant growth regulator prepared in this embodiment contains only the active component, which consists of methyl jasmonate and rhamnolipid; the preparation method is as follows:

[0033] Plant growth regulators were prepared by dissolving methyl jasmonate and rhamnolipin in water to achieve a concentration of 100 μM for methyl jasmonate and a volume concentration of 0.05% for rhamnolipin.

[0034] Example 3: Preparation of plant growth regulators

[0035] The plant growth regulator prepared in this embodiment contains only the active component, which consists of methyl jasmonate and rhamnolipid; the preparation method is as follows:

[0036] Plant growth regulators were prepared by dissolving methyl jasmonate and rhamnolipin in water to achieve a concentration of 300 μM for methyl jasmonate and a volume concentration of 0.15% for rhamnolipin.

[0037] Example 4: Preparation of plant growth regulators

[0038] The plant growth regulator prepared in this embodiment contains an active component and a synergistic component. The active component consists of methyl jasmonate and rhamnolipid, while the synergistic component consists of potassium dihydrogen phosphate, zinc sulfate, and boric acid. The preparation method is as follows:

[0039] Plant growth regulators were prepared by dissolving methyl jasmonate, rhamnolipin, potassium dihydrogen phosphate, zinc sulfate, and boric acid in water to achieve a concentration of 200 μM for methyl jasmonate, 0.1% for rhamnolipin (v / v), 3.0 g / L for potassium dihydrogen phosphate, 1.0 g / L for zinc sulfate, and 2.0 g / L for boric acid.

[0040] Example 5: Preparation of plant growth regulators

[0041] The plant growth regulator prepared in this embodiment contains an active component and a synergistic component. The active component consists of methyl jasmonate and rhamnolipid, while the synergistic component consists of potassium dihydrogen phosphate, zinc sulfate, and boric acid. The preparation method is as follows:

[0042] Plant growth regulators were prepared by dissolving methyl jasmonate, rhamnolipin, potassium dihydrogen phosphate, zinc sulfate, and boric acid in water to achieve a concentration of 200 μM for methyl jasmonate, 0.1% for rhamnolipin, 1.5 g / L for potassium dihydrogen phosphate, 0.5 g / L for zinc sulfate, and 1.0 g / L for boric acid.

[0043] Example 6: Preparation of plant growth regulators

[0044] The plant growth regulator prepared in this embodiment contains an active component and a synergistic component. The active component consists of methyl jasmonate and rhamnolipid, while the synergistic component consists of potassium dihydrogen phosphate, zinc sulfate, and boric acid. The preparation method is as follows:

[0045] Plant growth regulators were prepared by dissolving methyl jasmonate, rhamnolipin, potassium dihydrogen phosphate, zinc sulfate, and boric acid in water to achieve a concentration of 200 μM for methyl jasmonate, 0.1% for rhamnolipin (v / v), 4.5 g / L for potassium dihydrogen phosphate, 1.5 g / L for zinc sulfate, and 3.0 g / L for boric acid.

[0046] Comparative Example 1:

[0047] Methyl jasmonate was dispersed in water to a concentration of 200 μM, and used as plant growth regulator A.

[0048] Comparative Example 2:

[0049] Plant growth regulator B was prepared by dissolving rhamnolipin in water to achieve a volume concentration of 0.1%.

[0050] Comparative Example 3:

[0051] Plant growth regulator C was prepared by dissolving potassium dihydrogen phosphate, zinc sulfate, and boric acid in water to achieve a concentration of 3.0 g / L for potassium dihydrogen phosphate, 1.0 g / L for zinc sulfate, and 2.0 g / L for boric acid.

[0052] Experimental Example 1: Effects of plant growth regulators on eggplant growth under high temperature stress

[0053] 1. Test method:

[0054] Using the eggplant variety 'Yangchun Sanyue Eggplant' as the experimental material, the experiment was conducted at the experimental base of the College of Horticulture Science and Engineering, Shandong Agricultural University. Healthy seeds with plump and uniform size were selected, soaked in warm water, and then placed in a 28℃ constant temperature incubator for dark germination. Once the seeds showed white sprouts, they were evenly sown in 50-cell trays, one seed per cell. After the cotyledons of the seedlings were fully expanded, they were transplanted into 10 cm × 10 cm seedling pots, using a combination of substrate cultivation and nutrient solution irrigation. The cultivation substrate was prepared by mixing vermiculite and perlite in a 2:1 volume ratio; the nutrient solution used was a formula specifically formulated for Yamazaki eggplant. When the seedlings reached the three-leaf stage, vigorous and uniformly growing plants were transferred to a light-controlled incubator for acclimatization treatment. One week after the seedlings have recovered from transplant shock, the plant growth regulators prepared in Examples 1, 4, and Comparative Examples 1-3 were sprayed on the leaves once a day, with each application using 10 ml of the plant growth regulator per plant. An equal amount of water was sprayed as a control (CK).

[0055] Two days after continuous spraying, a high-temperature stress treatment was initiated: day / night temperatures of 40 ℃ / 30 ℃ and a photoperiod of 16 h / 8 h. Seedling samples were collected on day 14 after spraying to measure plant height, stem diameter, and total fresh weight. The aboveground and underground parts of the plant were separated, and the samples were placed in an oven at 105 ℃ for 15 min to deactivate the enzymes, then transferred to 75 ℃ to dry to constant weight. The dry weight of the underground parts, aboveground parts, and total plant were then measured, and the seedling vigor index was calculated using the following formula:

[0056] Strong seedling index = (stem diameter / plant height + underground dry weight / aboveground dry weight) × total plant dry weight.

[0057] 2. Test Results:

[0058] The results are shown in Table 1.

[0059] Table 1: Effects of plant growth regulators on eggplant growth under high temperature stress

[0060]

[0061] The results showed that spraying the plant growth regulator of the present invention could promote the growth of eggplant under high temperature stress, synergistically improve its seedling vigor index, and improve the growth performance of eggplant seedlings under high temperature stress.

[0062] Experimental Example 2: Effects of plant growth regulators on eggplant fruit coloring under high temperature stress

[0063] 1. Test method:

[0064] On evenings when temperatures are high (above 35°C), all eggplant plants in full bloom are sprayed with equal amounts of the plant growth regulators prepared in Examples 1, 4, and Comparative Examples 1-3. The spraying amount should be drip-like, and each eggplant only needs to be sprayed once during its entire growth period. Spraying with an equal amount of water serves as a control.

[0065] Two weeks after spraying the plant growth regulator, the coloring of the eggplant fruits was observed, and the anthocyanin content in the eggplant peel was measured. The measurement method is as follows:

[0066] Under the same conditions, eggplant peels of the same thickness were taken, rapidly and thoroughly ground with liquid nitrogen, transferred to 2 mL centrifuge tubes and weighed; 300 μL of 1% hydrochloric acid-methanol solution was added, and the mixture was placed in a light-proof refrigerator at 4℃ overnight; 200 μL of double-distilled water was added, followed by 500 μL of chloroform in a fume hood, and centrifuged at 14000 r / min for 5 min; 400 μL of the supernatant was transferred to a new 2 mL centrifuge tube in the fume hood; 400 μL of a mixture of 60% methanol (containing 1% hydrochloric acid): double-distilled water = 6:4 (volume ratio) was added to the centrifuge tube; the absorbance of each tube at 530 nm and 657 nm was measured using an ELISA reader, and the blank control was the above 60% methanol (containing 1% hydrochloric acid): double-distilled water mixture.

[0067] Calculate the anthocyanin content using the following formula:

[0068] Anthocyanin content = (A 530 -A 657 ) / mg·FW.

[0069] Using the anthocyanin content of the control group as a baseline (100%), the relative anthocyanin content (%) of the plant growth regulator treatments applied in Examples 1, 4, and Comparative Examples 1-3 compared to the control group was calculated.

[0070] 2. Test Results:

[0071] Two weeks after spraying the plant growth regulator, the coloring of the eggplant fruits was as follows: Figure 1 As shown; the results of the determination of the relative anthocyanin content in eggplant pericarp are as follows. Figure 2As shown.

[0072] The results showed that under high-temperature stress, spraying the plant growth regulators of Examples 1 and 4 of this invention effectively promoted eggplant fruit coloring and increased the anthocyanin content in the eggplant peel, with relative anthocyanin contents of 221.1% and 236.0%, respectively. In contrast, spraying the plant growth regulators of Comparative Examples 1, 2, and 3 resulted in relative anthocyanin contents of 163.9%, 116.1%, and 118.6%, respectively. Therefore, compared with spraying methyl jasmonate and rhamnolipid alone, the combined use of methyl jasmonate and rhamnolipid synergistically improved the coloring effect of eggplant fruit under high-temperature stress. Furthermore, adding synergistic components could further increase the anthocyanin content in the eggplant peel.

[0073] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A plant growth regulator, characterized in that, The plant growth regulator is composed of active components and synergistic components; The active components consist of methyl jasmonic acid and rhamnolipid; the concentration of methyl jasmonic acid in the plant growth regulator is 200 μM, and the volume concentration of rhamnolipid in the plant growth regulator is 0.1%. The synergistic component consists of potassium dihydrogen phosphate, zinc sulfate, and boric acid; the concentration of potassium dihydrogen phosphate in the plant growth regulator is 3.0 g / L, the concentration of zinc sulfate in the plant growth regulator is 1.0 g / L, and the concentration of boric acid in the plant growth regulator is 2.0 g / L.

2. The application of the plant growth regulator according to claim 1 in promoting fruit coloring in eggplant under high temperature stress, characterized in that, The temperature of the high-temperature stress is greater than or equal to 35°C.

3. The application according to claim 2, characterized in that, The application method to promote fruit coloring in eggplants under high temperature stress is as follows: before or during the occurrence of high temperature stress, spray the entire eggplant plant, which has entered the full flowering stage, with a plant growth regulator.

4. The application of the plant growth regulator according to claim 1 in promoting the growth of eggplant under high temperature stress, characterized in that, The temperature of the high-temperature stress is greater than or equal to 35°C.

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