Method for improving drought resistance of leymus chinensis under extreme drought condition

Abstract

The invention provides a method for improving drought resistance of leymus chinensis under an extreme drought condition, and belongs to the technical field of drought-resistant cultivation. The invention provides an application of a salicylic acid solution in drought resistance of leymus chinensis, which proves that salicylic acid can participate in regulating stomatal movement of leymus chinensis, reduce water loss and improve the water utilization efficiency of plants; activation of an anti-oxidation system in plants can be promoted, and oxidative stress reaction caused by drought is relieved. In addition, the application of salicylic acid can also induce leymus chinensis to generate more stress response proteins and enhance the stability of cell walls, so that the survival rate of plants in a drought environment is increased. Therefore, the salicylic acid aqueous solution is applied to drought resistance of leymus chinensis, so that development of a new biotechnological means is facilitated, increasingly severe drought challenges are dealt with, and health and stability of a grassland ecosystem are protected.

Description

Technical Field

[0001] The invention belongs to the technical field of drought-resistant cultivation, and in particular relates to a method for improving the drought resistance of Leymus chinensis under extreme drought conditions. Background Art

[0002] In 2023, the International Panel on Climate Change (IPCC) pointed out in its Sixth Assessment Report (AR6) that human activities have caused the global average temperature to rise by 1.1°C, a change that indicates that the Earth's climate system is undergoing an unprecedented transformation. In this context, the frequency and intensity of extreme climate events have increased. Due to its fragility and sensitivity to climate change, grassland ecosystems are particularly susceptible to extreme climate such as high temperature and drought. These extreme climate events interfere with the physiological processes of vegetation, thereby affecting the growth cycle of plants and leading to a decline in grassland productivity.

[0003] Obasi's research pointed out that meteorological disaster losses account for about 85% of all natural disaster losses, of which 50% are caused by drought. The report released by the IPCC pointed out that in 2021, natural disasters affected a total of 104.1676 million people worldwide. Among them, drought disasters affected the largest population, reaching 55.0467 million people, accounting for 52.84%, and direct economic losses ranked fifth; there were 13 drought disasters, affecting 15 countries and regions in total, mainly in the Middle East and East Africa. At present, frequent extreme drought events have brought serious impacts on agriculture, forestry, natural ecosystems, and socio-economic development.

[0004] As a herbaceous plant widely distributed in grassland areas, the study of the drought resistance of Leymus chinensis is particularly critical. This is because Leymus chinensis plays an important role in maintaining the ecological balance of grasslands, providing high-quality forage resources, and protecting soil structure. With the frequent occurrence of extreme drought events caused by global climate change, exploring how Leymus chinensis adapts to arid environments is of great significance for improving the stability of grassland ecosystems, ensuring the healthy development of animal husbandry, and promoting sustainable agricultural utilization. By in-depth research on the drought resistance mechanism of Leymus chinensis, we can not only better understand the adaptation strategies of plants to extreme climates, but also provide theoretical and scientific basis for grassland ecological protection and vegetation restoration in arid areas. Summary of the invention

[0005] The present invention provides a method for improving the drought resistance of Leymus chinensis under extreme drought conditions. Salicylic acid can control the closure of the stoma of the leaves to reduce the transpiration of the leaves, thereby ultimately achieving the effect of significantly improving the drought resistance.

[0006] The invention provides a method for improving the drought resistance of Leymus chinensis under extreme drought conditions. A salicylic acid solution is sprayed on the leaf surface of the Leymus chinensis. The concentration of the salicylic acid solution is 0.5 mM.

[0007] In a preferred embodiment of the present invention, the spraying is carried out in the evening of every day in windless and rainless weather for three consecutive days.

[0008] In a preferred embodiment of the present invention, the spraying includes spraying the leaves evenly with beads without dripping each time.

[0009] The present invention also provides a method for cultivating Leymus chinensis under drought conditions, comprising spraying a salicylic acid solution on the leaf surface of the Leymus chinensis, wherein the concentration of the salicylic acid solution is 0.5 mM.

[0010] In a preferred embodiment of the present invention, the spraying is carried out in the evening of every day in windless and rainless weather for three consecutive days.

[0011] In a preferred embodiment of the present invention, the spraying includes spraying the leaves evenly with beads without dripping each time.

[0012] The present invention also provides a method for maintaining soil moisture, comprising spraying a salicylic acid solution onto leaves of plants planted on the soil, wherein the concentration of the salicylic acid solution is 0.5 mM.

[0013] In a preferred embodiment of the present invention, the spraying is carried out in the evening of every day in windless and rainless weather for three consecutive days.

[0014] In a preferred embodiment of the present invention, the spraying includes spraying the leaves evenly with beads without dripping each time.

[0015] The invention also provides application of the method in inhibiting plant transpiration.

[0016] Beneficial effects: The present invention provides the application of salicylic acid solution in drought resistance of Leymus chinensis. The present invention proves that salicylic acid can participate in regulating the stomatal movement of Leymus chinensis, reduce water loss, and improve the water utilization efficiency of plants; it can promote the activation of the antioxidant system in plants and reduce the oxidative stress response caused by drought. In addition, the application of salicylic acid can also induce Leymus chinensis to produce more stress response proteins, enhance the stability of cell walls, and thus improve the survival rate of plants in drought environments. Therefore, the present invention applies salicylic acid aqueous solution to drought resistance of Leymus chinensis, which helps to develop new biotechnology means to cope with the increasingly severe drought challenges and protect the health and stability of grassland ecosystems. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the result of measuring the plant height of Leymus chinensis during extreme drought stress;

[0018] Figure 2 is the relative water content of Leymus chinensis under different salicylic acid concentrations;

[0019] Figure 3is the total chlorophyll content of Leymus chinensis under different salicylic acid concentrations;

[0020] Figure 4 is the soluble sugar content of Leymus chinensis under different salicylic acid concentrations;

[0021] Figure 5 is the proline content of Leymus chinensis at different salicylic acid concentrations;

[0022] Figure 6 is the malondialdehyde content of Leymus chinensis at different salicylic acid concentrations;

[0023] Figure 7 is the superoxide dismutase content of Leymus chinensis under different salicylic acid concentrations;

[0024] Figure 8 is the catalase activity of Leymus chinensis under different salicylic acid concentrations;

[0025] Fig. 9 is the peroxidase activity of Leymus chinensis under different salicylic acid concentrations;

[0026] Fig.10 The results of principal component analysis of the comprehensive performance of Leymus chinensis under different concentrations of salicylic acid;

[0027] Fig.11 This is a graph of stomatal conductance of Leymus chinensis under treatments with different concentrations of salicylic acid during extreme drought. Treatments 1 to 6 in the figure represent CK, T1, T2, T3, T4 and T5, respectively. DETAILED DESCRIPTION

[0028] The invention provides a method for improving the drought resistance of Leymus chinensis under extreme drought conditions. A salicylic acid solution is sprayed on the leaf surface of the Leymus chinensis. The concentration of the salicylic acid solution is 0.5 mM.

[0029] Salicylic acid in the present invention has the following English name: Salicylic acid; chemical formula: C7H6O3; molar mass: 138.12; CAS: 69-72-7. The present invention does not specifically limit the source of the salicylic acid, and conventional commercial sources in the art can be used, such as purchased from Proteintech in the embodiment.

[0030] In the embodiment of the present invention, by setting up multiple comparative experiments, it was verified that under extreme drought conditions, 0.25mM to 4mM salicylic acid solution was used to treat sheep grass, and it was found that too high or too low concentration was not conducive to the normal growth of sheep grass under extreme drought conditions. Only a salicylic acid solution with a concentration of 0.5mM can significantly improve the drought resistance of sheep grass, and significantly reduce the effect of drought stress on the height and elongation of sheep grass seedlings, which is beneficial to improving the adaptability of sheep grass to climate change.

[0031] Specifically, in one embodiment of the present invention, the beneficial effects of the salicylic acid solution of the present invention on Leymus chinensis are demonstrated from multiple perspectives. For example, 0.5 mM salicylic acid can maintain the normal growth and development of Leymus chinensis under drought conditions and relatively increase the yield, that is, it has the effect of significantly improving the drought resistance of plants; slowing down the consumption rate of soil moisture, thereby prolonging the survival time of Leymus chinensis under drought conditions; regulating and controlling the growth and development and physiological and biochemical processes of Leymus chinensis, and enhancing the adaptability of Leymus chinensis under water stress adversity; reducing the stomatal opening of Leymus chinensis leaves, inhibiting transpiration, and reducing water loss through the leaves, thereby maintaining soil moisture.

[0032] The salicylic acid solution of the present invention is an aqueous solution of salicylic acid. When preparing the solution, 34.53 mg of salicylic acid powder and 500 ml of distilled water are accurately weighed in 500 ml to finally obtain a 0.5 mM salicylic acid solution. When preparing, generally a small amount of distilled water is first poured into a beaker to dissolve the salicylic acid powder, and the solution is gently stirred with a stirring rod to accelerate the dissolution rate. After the salicylic acid powder is fully dissolved, the dissolved salicylic acid solution is poured into a volumetric flask to make up the volume, and finally the volumetric flask is sealed with a bottle stopper or a lid, and the solution is shaken well.

[0033] The present invention can be applied with a watering can when spraying, so that the solution is evenly attached to the surface of the plant leaves, and sprayed until the surface of the leaves is evenly beaded and does not drip. The present invention needs to be sprayed every evening in windless and rainless weather, and sprayed continuously for three days. The 0.5mM salicylic acid solution sprayed by the present invention can reduce the transpiration of the leaves by controlling the stomata closure of the leaves of the sheep grass, and finally achieve the effect of significantly improving drought resistance.

[0034] The present invention also provides a method for cultivating Leymus chinensis under drought conditions, comprising spraying a salicylic acid solution on the leaf surface of the Leymus chinensis, wherein the concentration of the salicylic acid solution is 0.5 mM.

[0035] In one embodiment of the present invention, it is confirmed that under extreme drought conditions, a 0.5 mM salicylic acid solution can significantly improve the drought resistance of Leymus chinensis, thereby allowing the cultivation of Leymus chinensis with little or even no water under drought conditions.

[0036] The present invention also provides a method for maintaining soil moisture, comprising spraying a salicylic acid solution onto leaves of plants planted on the soil, wherein the concentration of the salicylic acid solution is 0.5 mM.

[0037] The method of the present invention is the same as described above and will not be described in detail here.

[0038] The invention also provides application of the method in inhibiting plant transpiration.

[0039] The salicylic acid described in the present invention, as a plant hormone, has a significant regulating effect on the drought resistance of Leymus chinensis and can enhance the drought resistance of plants in various ways, such as reducing the stomatal opening of Leymus chinensis leaves, inhibiting transpiration, and reducing water loss through leaves, thereby maintaining soil moisture.

[0040] In order to further illustrate the present invention, a method for improving drought resistance of Leymus chinensis under extreme drought conditions provided by the present invention is described in detail below in conjunction with embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0041] Example 1

[0042] 1. Experimental Materials

[0043] The sheepgrass seeds are germinated in advance, and the sheepgrass with the same or similar growth and health conditions that are cultivated is used as the experimental material.

[0044] 2. Experimental methods

[0045] (1) Set 5 salicylic acid (SA) concentrations, namely:

[0046] T1: under extreme drought stress, the salicylic acid spraying concentration was 0.25mmol / L;

[0047] T2: under extreme drought stress, the salicylic acid spraying concentration was 0.50mmol / L;

[0048] T3: under extreme drought stress, the salicylic acid spraying concentration was 1.00mmol / L;

[0049] T4: under extreme drought stress, the salicylic acid spraying concentration was 2.00mmol / L;

[0050] T5: under extreme drought stress, the salicylic acid spraying concentration was 4.00mmol / L;

[0051] Control (CK): sprayed with an equal amount of water under extreme drought stress.

[0052] (2) Simulating extreme drought stress conditions

[0053] The test site is located at the extreme drought test platform of the Ecological Grassland and Animal Husbandry Development Research Center of Shanxi Agricultural University, Taigu District, Jinzhong City, Shanxi Province (N37.42°, E112.58°), with an altitude of 804.6m. The test adopts the potting method, and the soil in the flowerpot is the seedling medium (nutrient soil), with an initial water content of 7.40%. After watering, the soil water content in all flowerpots is maintained at 53.64%. At this time, the flowerpots are moved under the awning for extreme drought treatment and no longer rehydrated under outdoor natural conditions.

[0054] By sorting and analyzing the meteorological data of Taigu District from 1978 to 2021, combined with the experimental design of the International Drought Network, and based on the growing season of Leymus chinensis, July and August were finally set as the duration of extreme drought treatment in the platform. Extreme drought treatment is achieved by using a rain shelter to block 100% of the precipitation from the outside. In this experiment, the Leymus chinensis potted plants were subjected to extreme drought treatment on July 19, 2024. There was no artificial watering during the drought period. Relevant indicators were observed and measured 21 days after treatment.

[0055] (3) Experimental methods

[0056] Starting from July 16, 2024, the leaves were sprayed every evening for 3 consecutive days. On July 19, the sheep grass was subjected to drought stress treatment and observed and measured 21 days after the treatment. Each treatment was repeated 6 times, for a total of 36 treatments. Finally, the optimal salicylic acid (SA) concentration was screened out through comprehensive analysis.

[0057] (4) Measurement indicators

[0058] Morphological indicators: Leymus chinensis plant height;

[0059] Physiological and biochemical indicators: relative water content (RWC) of sheep fescue leaves, total chlorophyll content (TCH), soluble sugar content (SS), proline (PRO) content, malondialdehyde (MDA) content, superoxide dismutase (SOD) content, catalase (CAT) content, and peroxidase (POD) content.

[0060] (5) Experimental results:

[0061] During the extreme drought stress period, the plant height of Leymus chinensis under different salicylic acid concentrations was measured on July 19, July 23, July 27, July 31, August 4, and August 8. The results are shown in Table 1. Figure 1 As shown in the figure, during the drought stress period, the plant height of Leymus chinensis at different salicylic acid concentrations showed a downward trend. Compared with the control group, the decrease in plant height of Leymus chinensis at T2 and T3 salicylic acid concentrations was the lowest, at 7% and 5%, respectively, indicating that the application of salicylic acid can weaken the effect of drought stress on the plant height elongation of Leymus chinensis seedlings (Table 3).

[0062] At the same time, the physiological and biochemical indicators related to the stress resistance of Leymus chinensis were also measured. Figures 2 to 9As shown, the results showed that under extreme drought, the total chlorophyll content and proline content of Leymus chinensis treated with T2 showed the maximum value, and were significantly higher than those of the control group. The main function of proline in plants is to act as an osmotic regulating substance, maintain the osmotic balance inside and outside the cells, and enhance plant stress resistance. The results of this experiment showed that salicylic acid at a concentration of T2 can promote the accumulation of proline in Leymus chinensis when responding to extreme drought, thereby enabling it to better adapt to drought adversity. At the T2 salicylic acid concentration, the relative water content, soluble sugar, malondialdehyde content, superoxide dismutase activity, and catalase activity of Leymus chinensis leaves were higher than those of the control group. In addition, the results of stomatal conductance of Leymus chinensis under different concentrations of salicylic acid treatments are shown in Tables 2 and Fig.11 As shown, the results showed that under the T2 concentration salicylic acid treatment, the stomatal conductance of Leymus chinensis was the smallest in extreme drought stress, which inhibited the transpiration rate and reduced the loss of water in the body, thereby improving its adaptability to extreme drought.

[0063] Through comprehensive analysis of all measured indicators, the results showed that under extreme drought conditions, salicylic acid solution with a concentration of T2 (0.5mmol / L) could significantly improve the drought resistance of Leymus chinensis.

[0064] The principal component analysis of the comprehensive performance of Leymus chinensis under different concentrations of salicylic acid was further conducted, and the eight Leymus chinensis indicators were represented by three principal component axes, namely, the relative water content (RWC) of Leymus chinensis leaves, total chlorophyll content (TCH), soluble sugar content (SS), proline (PRO), malondialdehyde (MDA), superoxide dismutase activity (SOD), catalase activity (CAT), and peroxidase activity (POD). The analysis results are as follows Fig.10 As shown, the three principal components with eigenvalues ​​greater than 1 are extracted, which cumulatively explain 91.150% of the total variance of the comprehensive performance of Leymus chinensis under extreme drought treatment, and it is certain to use it to evaluate the comprehensive performance of Leymus chinensis. Therefore, the three principal components extracted by the present invention are y1, y2 and y3, respectively, and the coefficient matrix formula of the comprehensive performance score of Leymus chinensis under different concentrations of salicylic acid treatment is expressed as follows:

[0065] y1=0.489RWC+0.472TCH+0.236SS+0.351PRO+0.460MDA-0.117SOD-0.073CAT+0.358POD;

[0066] y2=-0.180RWC+0.171TCH+0.340SS+0.386PRO+0.083MDA+0.596SOD+0.370CAT-0.418POD;

[0067] y3=0.045RWC-0.053TCH-0.493SS-0.144PRO+0.339MDA+0.029SOD+0.758CAT+0.204POD;

[0068] y=0.4721y1+0.3056y2+0.1338y3.

[0069] Table 1 Ranking of comprehensive performance scores of Leymus chinensis under extreme drought with different concentrations of salicylic acid

[0070] deal with <![CDATA[y1 score]]> <![CDATA[y2 score]]> <![CDATA[y3 score]]> y score Sorting CK -1.94 -1.45 -0.18 -1.39 6 T1 -2.63 1.37 0.13 -0.81 5 T2 1.61 2.41 0.32 1.54 1 T3 1.72 -1.43 1.63 0.59 2 T4 1.57 -0.49 -1.60 0.38 3 T5 -0.33 -0.39 -0.31 -0.32 4

[0071] Table 2 Stomatal conductance of Leymus chinensis at different salicylic acid concentrations (mmolm -2 s -1 )

[0072] deal with <![CDATA[Stomatal conductance (gs) of Leymus chinensis / mmolm -2 s -1 > CK 256.50 T1 215.67 T2 180.17 T3 258.67 T4 191.83 T5 209.67

[0073] Table 3 Plant height of Leymus chinensis during extreme drought stress (mm)

[0074] CK T1 T2 T3 T4 T5 July 19 240 280 226 276 235 252 July 23 253 270 220 266 227 245 July 27 251 261 217 266 226 238 July 31 244 260 215 265 226 235 August 4 225 251 210 264 215 232 August 8 212 245 210 261 199 195

[0075] Judging from the ranking of the comprehensive performance scores of sheep fescue under extreme drought, the comprehensive performance scores of the control group (CK), T1 (0.25mmol / L) and T5 (4.00mmol / L) were all negative, indicating that the growth and development of sheep fescue were significantly affected under extreme drought, and that the application of too low or too high concentrations of salicylic acid would also affect the effective drought resistance of drought-resistant agents; under the T2 (0.50mmol / L) salicylic acid treatment, the sheep fescue had the highest comprehensive performance score, which indicates that under extreme drought treatment, the use of 0.50mmol / L salicylic acid solution can significantly improve the drought resistance of sheep fescue, which is beneficial to improving the adaptability of sheep fescue to climate change.

[0076] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for improving drought resistance of Leymus chinensis under extreme drought conditions, characterized in that: A salicylic acid solution was sprayed on the leaves of Leymus chinensis, wherein the concentration of the salicylic acid solution was 0.5 mM.

2. The method according to claim 1, characterized in that: The spraying is carried out in the evening of every day in windless and rainless weather for three consecutive days.

3. The method according to claim 1 or 2, characterized in that: The spraying includes spraying each time to evenly bead the leaf surface without dripping.

4. A method for cultivating Leymus chinensis under drought conditions, characterized in that: The method comprises spraying a salicylic acid solution on the leaf surface of the sheep grass, wherein the concentration of the salicylic acid solution is 0.5 mM.

5. The method according to claim 4, characterized in that: The spraying is carried out in the evening of every day in windless and rainless weather for three consecutive days.

6. The method according to claim 4 or 5, characterized in that: The spraying includes spraying each time to evenly bead the leaf surface without dripping.

7. A method for maintaining soil moisture, characterized in that: The method comprises spraying a salicylic acid solution having a concentration of 0.5 mM onto leaves of plants grown on soil.

8. The method according to claim 7, characterized in that: The spraying is carried out in the evening of every day in windless and rainless weather for three consecutive days.

9. The method according to claim 7 or 8, characterized in that: The spraying includes spraying each time to evenly bead the leaf surface without dripping.

10. Use of the method according to any one of claims 4 to 6 or the method according to any one of claims 7 to 9 for inhibiting plant transpiration.

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