Application of gamma-aminobutyric acid in relieving saline-alkali stress of cotton and method for relieving saline-alkali stress of cotton

Abstract

The invention belongs to the technical field of crop cultivation, and particularly relates to application of gamma-aminobutyric acid in relieving saline-alkali stress of cotton and a method for relieving the saline-alkali stress of the cotton. According to the method, gamma-aminobutyric acid is used as an exogenous additive, and when the cotton is stressed by a secondary salt solution with the salt content of 0.45%-0.47% and the pH value of 7.5-8.0, the gamma-aminobutyric acid is added into the secondary salt solution; gamma-aminobutyric acid relieves secondary salt solution stress by improving superoxide dismutase activity of cotton, improving peroxidase activity of cotton, reducing malondialdehyde content of cotton, improving catalase activity of cotton, reducing superoxide anion content, reducing H2O2 content of cotton and improving soluble protein content of cotton; compared with other plant growth regulators, the gamma-aminobutyric acid has higher cotton saline-alkali stress relieving activity. And the gamma-aminobutyric acid is an amino acid naturally existing in an organism, has no toxicity to a human body, has no residual toxicity and residual effect after being used for treating cotton, and has practical utilization value.

Description

Technical Field

[0001] The invention belongs to the technical field of crop cultivation, and particularly relates to application of gamma-aminobutyric acid in alleviating saline-alkali stress of cotton and a method for alleviating saline-alkali stress of cotton. Background Art

[0002] Cotton is a very important component of global cash crops, and Xinjiang is the main cotton producing area in my country. Compared with other field crops, cotton is a crop with strong salt-alkali tolerance, but the degree of salinization in Xinjiang is too high, which leads to the persecution of cotton seed germination, growth, development and physiological and biochemical metabolism under high concentration of salt-alkali stress, which eventually leads to non-germination, dead seedlings and plant death. Therefore, the study of exogenous mitigation substances is of great significance to improving cotton yield.

[0003] In the existing technology, in the study of applying exogenous substances to alleviate saline-alkali stress, only a single salt stress (NaCl) is usually considered, and the complex salt composition of saline-alkali soil and the associated high alkali content in actual production are often ignored. The impact on plant seedlings, resulting in the problem that the exogenous substances screened for single salt stress cannot be applied in practice. Therefore, it is particularly important to find exogenous mitigating substances to alleviate cotton salt-alkali stress in view of the complex saline-alkali environment in Xinjiang. Summary of the invention

[0004] The purpose of the present invention is to provide an application of gamma-aminobutyric acid in alleviating saline-alkali stress of cotton and a method for alleviating saline-alkali stress of cotton, which can effectively alleviate the stress of complex salt composition and associated high alkali content on cotton, and no residual toxicity or residual effect exists on cotton after treatment.

[0005] The present invention provides the use of gamma-aminobutyric acid in alleviating cotton saline-alkali stress, wherein the saline-alkali stress is secondary salt solution stress;

[0006] The salt content of the secondary salt solution is 0.45% to 0.47%, and the pH value is 7.5 to 8.0.

[0007] Preferably, the γ-aminobutyric acid alleviates the salinity-alkali stress of cotton by one or more of increasing the superoxide dismutase activity of cotton, increasing the peroxidase activity of cotton, reducing the malondialdehyde content of cotton, increasing the catalase activity of cotton, reducing the superoxide anion content, reducing the H2O2 content of cotton and increasing the soluble protein content of cotton.

[0008] Preferably, the cotton includes Xinluzhong No. 42 and / or Xinluzhong No. 22.

[0009] Preferably, the secondary salt solution includes components with the following concentrations: NaHCO3 0.72-0.73 g / L, NaSO4 20.03-20.04 g / L, K2SO4 1.68-1.69 g / L, MgSO4·7H2O 14.34-14.38 g / L, and CaCl2 10.76-10.77 g / L.

[0010] Preferably, the usage ratio of the γ-aminobutyric acid to the secondary salt solution is 0.51-0.52 g:1L.

[0011] The present invention also provides a method for alleviating saline-alkali stress of cotton, wherein γ-aminobutyric acid is added to a secondary salt solution and then cotton seedlings are cultured;

[0012] The salt content of the secondary salt solution is 0.45% to 0.47%, and the pH value is 7.5 to 8.0.

[0013] Preferably, the usage ratio of the γ-aminobutyric acid to the secondary salt solution is 0.51-0.52 g:1L.

[0014] Preferably, the secondary salt solution includes components with the following concentrations: NaHCO3 0.72-0.73 g / L, NaSO4 20.03-20.04 g / L, K2SO4 1.68-1.69 g / L, MgSO4·7H2O 14.34-14.38 g / L, and CaCl2 10.76-10.77 g / L.

[0015] Preferably, the culture method is hydroponics;

[0016] The culture conditions are: ambient temperature 28°C, humidity 85%, 16 / 8h light;

[0017] The culture time is 4 to 48 hours.

[0018] Preferably, the cotton seedlings are at the three-leaf stage.

[0019] Beneficial effects:

[0020] When cotton is subjected to secondary salt solution stress with a salt content of 0.45% to 0.47% and a pH of 7.5 to 8.0, γ-aminobutyric acid can alleviate the stress of secondary salt solution by increasing the activity of superoxide dismutase in cotton, increasing the activity of peroxidase in cotton, reducing the content of malondialdehyde in cotton, increasing the activity of catalase in cotton, reducing the content of superoxide anions, reducing the content of H2O2 in cotton, and increasing the content of soluble protein in cotton; compared with other plant growth regulators, γ-aminobutyric acid has a higher activity in alleviating cotton salt-alkali stress. Moreover, γ-aminobutyric acid is an amino acid naturally present in organisms, has no toxicity to the human body, has no residual toxicity or residual effect on cotton after treatment, and has practical utilization value.

[0021] Furthermore, the secondary salt solution configured by the present invention is similar to the secondary saline-alkali land environment in Korla, Xinjiang. By simulating the growth environment of secondary saline-alkali land in Korla, Xinjiang, it makes up for the deficiency of the prior art that only a single salt stress (NaCl) is considered, and the complex salt composition of saline-alkali land and the associated high alkali content in actual production have been ignored. The impact on plant seedlings is more in line with actual production applications and provides a new theoretical basis and new ideas for using exogenous substances to alleviate salt-alkali stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments are briefly introduced below.

[0023] Figure 1 The growth of the leaves of Xinluzhong No. 42 after 4 hours of treatment in each treatment group of Example 1;

[0024] Figure 2 The growth of the leaves of Xinluzhong No. 42 after 8 hours of treatment in each treatment group of Example 1;

[0025] Figure 3 The growth of the leaves of Xinluzhong No. 42 after 12 hours of treatment in each treatment group of Example 1;

[0026] Figure 4 The growth of the leaves of Xinluzhong No. 42 after 24 hours of treatment in each treatment group of Example 1;

[0027] Figure 5 The growth of the leaves of Xinluzhong No. 42 after 48 hours of treatment in each treatment group of Example 1;

[0028] Figure 6 The leaf growth of Xinluzhong No. 22 in each treatment group of Example 1 after 8 hours of treatment;

[0029] Figure 7 The leaf growth of Xinluzhong No. 22 after 12 hours of treatment in each treatment group of Example 1;

[0030] Figure 8 The leaf growth of Xinluzhong No. 22 after 24 hours of treatment in each treatment group of Example 1;

[0031] Fig. 9 This is a comparison of the growth of Xinluzhong No. 42 after 4 to 24 hours of treatment with treatment group 2 (secondary salt) and treatment group 4 (secondary salt + GABA) in Example 1; wherein, from top to bottom are treatment group 2 and treatment group 4, and the treatment time from left to right is 4h, 8h, 12h, 24h and 48h;

[0032] Fig.10 This is a comparison of the growth of Xinluzhong No. 22 after 4 to 24 hours of treatment in Treatment 2 (secondary salt) and Treatment 4 (secondary salt + GABA) in Example 1; wherein, from top to bottom are Treatment 4 and Treatment 2, and the treatment time from left to right is 4h, 8h, 12h, 24h and 48h;

[0033] Fig.11 The superoxide dismutase (SOD) activity of Xinluzhong 42 under different exogenous stress treatments;

[0034] Fig.12 The superoxide dismutase (SOD) activity of Xinluzhong 22 under different exogenous stress treatments;

[0035] Fig.13 The peroxidase (POD) activity of Xinluzhong 22 under different exogenous stress treatments;

[0036] Fig.14 The peroxidase (POD) activity of Xinluzhong 42 under different exogenous stress treatments;

[0037] Fig.15 The malondialdehyde (MDA) content of Xinluzhong 22 under different exogenous stress treatments;

[0038] Fig.16 The malondialdehyde (MDA) content of Xinluzhong 42 under different exogenous stress treatments;

[0039] Fig.17 Catalase (CAT) activity of Xinluzhong 42 under different exogenous stress treatments;

[0040] Fig.18 Catalase (CAT) activity of Xinluzhong 22 under different exogenous stress treatments;

[0041] Fig.19 The superoxide anion (O2 - )content;

[0042] Fig. 20 The superoxide anion (O2 -)content;

[0043] Fig.21 H2O2 content of Xinluzhong 42 under different exogenous stress treatments;

[0044] Fig. 22 H2O2 content of Xinluzhong 22 under different exogenous stress treatments;

[0045] Fig.23 The soluble protein content of Xinluzhong 42 under different exogenous stress treatments;

[0046] Fig.24 This is the soluble protein content of Xinluzhong No. 22 under different exogenous stress treatments. DETAILED DESCRIPTION

[0047] The present invention provides application of gamma-aminobutyric acid in alleviating cotton saline-alkali stress, wherein the saline-alkali stress is secondary salt solution stress; the salt content of the secondary salt solution is 0.45% to 0.47%, preferably 0.47%; and the pH of the secondary salt solution is 7.5 to 8.0, preferably 7.8.

[0048] In the present invention, the cotton preferably includes Xinluzhong No. 42 and / or Xinluzhong No. 22. The gamma-aminobutyric acid of the present invention preferably alleviates the saline-alkali stress of cotton by increasing the superoxide dismutase activity of cotton, increasing the peroxidase activity of cotton, reducing the malondialdehyde content of cotton, increasing the catalase activity of cotton, reducing the superoxide anion content, reducing the H2O2 content of cotton, and increasing the soluble protein content of cotton. It is further preferred to alleviate the saline-alkali stress of cotton by increasing the superoxide dismutase activity of cotton, increasing the peroxidase activity of cotton, reducing the malondialdehyde content of cotton, increasing the catalase activity of cotton, reducing the superoxide anion content, reducing the H2O2 content of cotton, and increasing the soluble protein content of cotton.

[0049] In the present invention, the dosage ratio of the γ-aminobutyric acid to the secondary salt solution is preferably 0.51-0.52 g:1 L; the secondary salt solution preferably includes components with the following concentrations: NaHCO3 0.72-0.73 g / L, NaSO4 2 0.03-20.04 g / L, K2SO4 1.68-1.69 g / L, MgSO4·7H2O 14.34-14.38 g / L, CaCl2 10.76-10.77 g / L, and further preferably includes components with the following concentrations: NaHCO3 0.72 g / L, NaSO4 2 0.04 g / L, K2SO4 1.69 g / L, MgSO4 14.38 g / L, CaCl2 10.77 g / L. The secondary salt solution of the present invention preferably uses a 1 / 2 concentration of Hoagland nutrient solution as a solvent. The invention simulates the growth environment of secondary saline-alkali land in Korla area of ​​Xinjiang. The configured secondary salt solution has a complex salt composition and is accompanied by a high alkali content, which makes up for the deficiency of the prior art that only a single salt stress (NaCl) is considered. It proves that gamma-aminobutyric acid can alleviate the stress of the complex salt composition and the associated high alkali content on cotton, which is in line with actual production application and provides a new theoretical basis and new ideas for utilizing exogenous substances to alleviate salt-alkali stress.

[0050] The present invention also provides a method for alleviating saline-alkali stress of cotton, comprising adding gamma-aminobutyric acid to a secondary salt solution and then culturing cotton seedlings; the salt content of the secondary salt solution is 0.45% to 0.47%, preferably 0.47%; and the pH of the secondary salt solution is 7.5 to 8.0, preferably 7.8.

[0051] In the present invention, the culture method is preferably hydroponics, and more preferably indoor hydroponics; the culture conditions are preferably: ambient temperature 28°C, humidity 85%, 16 / 8h light; the culture time is preferably 4 to 48h, more preferably 8 to 24h, and more preferably 12h. The present invention performs indoor hydroponics, which is not restricted by seasons and is not affected by external climate.

[0052] In the present invention, the seedling age of the cotton seedlings is preferably at the three-leaf stage. The present invention preferably obtains the cotton seedlings by seed germination and transplanting hydroponics. The seed germination method of the present invention is preferably three-layer filter paper roll germination; the three-layer filter paper roll germination step preferably includes: placing the cotton seeds on one side of a double-layer filter paper, and then covering the third filter paper on top of the seeds, adding water to moisten, folding the three layers of filter paper into a filter paper roll, adding water to culture, and obtaining germinated seedlings; the height of the water is preferably 1 / 3 of the height of the filter paper roll; the culture method is preferably shading culture; the environmental temperature of the culture is preferably 28°C, and the environmental humidity is preferably 85%; the culture time is preferably 7d.

[0053] After obtaining the germinated seedlings, the present invention preferably uses clean water to culture the germinated seedlings, and when the first true leaf grows, it is changed to a 1 / 2 concentration of Hoagland nutrient solution for culture, and then the 1 / 2 concentration of Hoagland nutrient solution is changed every 3 days to obtain three-leaf stage cotton seedlings. The environmental temperature of the clean water culture of the present invention is preferably 28°C, the environmental humidity is preferably 85%, and the light is 16 / 8h; the environmental temperature of the 1 / 2 concentration of Hoagland nutrient solution culture is preferably 28°C, the environmental humidity is preferably 85%, and the light is 16 / 8h.

[0054] The composition of the secondary salt solution and the usage ratio of γ-aminobutyric acid to the secondary salt solution of the present invention are preferably consistent with those described above, and will not be described in detail here.

[0055] To further illustrate the present invention, the application of γ-aminobutyric acid in alleviating cotton saline-alkali stress and a method for alleviating cotton saline-alkali stress provided by the present invention are described in detail below in conjunction with the accompanying drawings and examples, but they should not be construed as limiting the scope of protection of the present invention.

[0056] Example 1

[0057] 1. Experimental Materials

[0058] The highly salt-tolerant variety Xinluzhong No. 22 and the salt-sensitive variety Xinluzhong No. 42.

[0059] 2. Experimental Methods

[0060] (1) Seed preparation: Seeds of experimental materials were selected, delinted with concentrated sulfuric acid (98 Vol%), washed with clean water, disinfected with 1 wt.% sodium hypochlorite for 15 min, washed with clean water and dried.

[0061] (2) Seed germination: Use three-layer filter paper rolls for germination. Select seeds with uniform plumpness and color and place them evenly on one side of the double-layer filter paper. Then, place the third filter paper on the double-layer filter paper with seeds. After adding appropriate amount of water to moisten, fold the three-layer filter paper into a filter paper roll and place it in a water tank with the seed end on top. The water level in the water tank should reach about 1 / 3 of the height of the filter paper roll. Shade for 7 days, ambient temperature 28℃, humidity 85%.

[0062] (3) Transplanting and hydroponics: After 7 days of constant temperature cultivation in a 28℃ artificial climate box, select seedlings with consistent growth and transplant them for hydroponics. Cultivate in clear water for about 5 days. When the first true leaf grows out, change to 1 / 2 concentration Hoagland nutrient solution for cultivation. Then change 1 / 2 concentration Hoagland nutrient solution every 3 days. The environment temperature is 28℃, the humidity is 85%, and the light intensity is 16 / 8h (i.e. 16h light cultivation, 8h dark cultivation, and the light intensity is 8000-10000lx). During the cultivation process, pay attention to picking up dead seedlings and selecting and replacing seedlings with consistent growth.

[0063] (4) Stress treatment: After the seedlings were cultured to the three-leaf stage (about 20 days), seedlings with the same growth trend were selected and randomly divided into 6 treatment groups for the following treatments:

[0064] Treatment 1 (CK): Continue to use 1 / 2 concentration of Hoagland nutrient solution to culture seedlings;

[0065] Treatment 2 (secondary salt): 1 / 2 concentration of Hoagland nutrient solution was replaced with reagent 1, and seedlings were cultured; wherein reagent 1 was composed of the following components: NaHCO3 0.72 g / L, NaSO4 20.04 g / L, K2SO4 1.69 g / L, MgSO4 14.38 g / L, CaCl2 10.77 g / L and the remainder of 1 / 2 concentration of Hoagland nutrient solution (i.e., 0.0086 mol / L NaHCO3, 0.1411 mol / L Na2SO4, 0.0097 mol / L K2SO4, 0.0583 mol / LMgSO4·7H2O, 0.0970 mol / L CaCl2, pH = 7.5-8.0);

[0066] Treatment 3 (GABA): 1 / 2 concentration of Hoagland nutrient solution was replaced with reagent 2, and seedlings were cultured; wherein reagent 2 consisted of the following components at the following concentrations: 5 mmol / L γ-aminobutyric acid (GABA) and the remainder of 1 / 2 concentration of Hoagland nutrient solution;

[0067] Treatment 4 (secondary salt + GABA): 1 / 2 concentration of Hoagland nutrient solution was replaced with reagent 3 to culture seedlings; reagent 2 consisted of the following components: NaHCO3 0.72 g / L, NaSO4 20.04 g / L, K2SO4 1.69 g / L, MgSO4 14.38 g / L, CaCl2 10.77 g / L, 5 mmol / L γ-aminobutyric acid (GABA) and the remainder of 1 / 2 concentration of Hoagland nutrient solution;

[0068] Treatment 5 (VGB): 1 / 2 concentration of Hoagland nutrient solution was replaced with reagent 3 to culture seedlings; wherein reagent 2 consisted of the following components: 0.5 mmol / L vigabatrin (VGB) and the remainder of 1 / 2 concentration of Hoagland nutrient solution;

[0069] Treatment group 6 (secondary salt + VGB): The 1 / 2 concentration of Hoagland nutrient solution was replaced with reagent 3 to culture seedlings; wherein reagent 2 was composed of the following concentrations of components: NaHCO3 0.72 g / L, NaSO4 20.04 g / L, K2SO4 1.69 g / L, MgSO4 14.38 g / L, CaCl2 10.77 g / L, 0.5 mmol / L vigabatrin (VGB) and the remainder 1 / 2 concentration of Hoagland nutrient solution.

[0070] (5) Step (4) During the treatment process of each treatment group, the growth of cotton seedlings was observed, and the relevant indicators of cotton seedlings were tested in the following manner. The results were as follows: Figures 1 to 24 As shown in Tables 1 and 2.

[0071] ①Superoxide dismutase (SOD) activity: measured by XOD-NBT method;

[0072] ②Peroxidase (POD) activity: using guaiacol method;

[0073] ③ Malondialdehyde (MDA) content: measured by micro-method;

[0074] ④ Catalase (CAT) activity: using UV absorption method;

[0075] ⑤Superoxide anion (O2 - ) content: determined by hydroxylamine hydrochloride oxidation method;

[0076] ⑥H2O2 content: determined by titanium sulfate method;

[0077] ⑦Soluble protein content: determined by Coomassie Brilliant Blue method.

[0078] Table 1 Test results of relevant indicators of each treatment group of Xinluzhong 42

[0079]

[0080]

[0081] Note: Different letters in the same column indicate significant differences among treatments at the P<0.05 level. Same below.

[0082] Table 2 Test results of relevant indicators of each treatment group of Xinluzhong 22

[0083]

[0084]

[0085] according to Figures 1 to 10It can be seen that the relevant indicators of the two varieties of cotton have obvious changes under various treatment conditions. At 4 hours, Xinluzhong 42 was obviously wilted in the secondary salt + VGB treatment, while Xinluzhong 22 was not obvious. At 8 hours, Xinluzhong 42 was obviously wilted in the secondary salt and secondary salt + VGB treatment, and Xinluzhong 22 was obviously wilted in the secondary salt + VGB treatment. At 12 hours, Xinluzhong 42 was obviously wilted in the secondary salt and secondary salt + VGB treatment. The cotton plants wilted obviously in the presence of secondary salts and GABA, and Xinluzhong 22 wilted obviously in the presence of secondary salts and VGB. At 24 hours, Xinluzhong 42 wilted obviously in the presence of secondary salts and secondary salts + VGB, and the early wilting of secondary salts + GABA continued to be alleviated. Xinluzhong 22 wilted obviously in the presence of secondary salts and secondary salts + VGB, and at 48 hours, Xinluzhong 42 and Xinluzhong 22 completely wilted in the presence of secondary salts and secondary salts + VGB. VGB has an inhibitory effect on GABA, and cotton plants also produce GABA themselves. The GABA produced by themselves is not enough to alleviate the damage caused by stress, and exogenous application is required to extend the relief time. The highly tolerant variety Xinluzhong 22 is more resistant to stress than the salt-sensitive variety 42 under the same stress. GABA can not only alleviate stress, but also accelerate plant growth.

[0086] Regarding the SOD activity test results, according to Tables 1 to 2 and Figures 11-12 It can be seen that with the increase of stress time, except for the CK treatment, the SOD activity of the two varieties fluctuated greatly. The SOD activity of the two varieties in the secondary salt treatment first increased and then decreased, and the SOD activity of the GABA treatment was significantly higher than that of other treatments. During the 0-24h of stress, the SOD activity of the two varieties in the GABA treatment continued to increase. 24-48h after the stress, as the content of reactive oxygen free radicals in the plant body decreased or stabilized, the SOD activity of the two varieties showed a downward trend. The SOD activity of Xinluzhong No. 22 in the secondary salt + GABA treatment for 0-8h stress was lower than that in the secondary salt treatment, and the SOD activity of the secondary salt + GABA treatment for 8-48h was higher than that in the secondary salt treatment; the SOD activity of Xinluzhong No. 42 in the secondary salt + GABA treatment for 0-24h stress was lower than that in the secondary salt treatment, and the SOD activity of the secondary salt + GABA treatment for 24-48h stress was higher than that in the secondary salt treatment. The results showed that the two cotton varieties had different sensitivities to GABA to alleviate salt stress. Xinluzhong 22 responded quickly to the stress, while Xinluzhong 42 responded slowly, which may be related to their different stress resistance. GABA can increase the activity of cotton SOD;

[0087] Regarding the POD activity test results, according to Tables 1 to 2 and Figures 13-14It can be seen that the POD activity of the two cotton varieties in the CK treatment did not change significantly with the increase of stress time, while other treatments showed obvious changes, and the POD activity showed an overall upward trend. The POD activity of Xinluzhong No. 22 in the 0-8h secondary salt + GABA treatment was lower than that in the secondary salt treatment, and the POD activity in the 8-48h secondary salt + GABA treatment was higher than that in the secondary salt treatment; the POD activity of Xinluzhong No. 42 in the 0-12h secondary salt + GABA treatment was higher than that in the secondary salt treatment, and the POD activity in the 12-48h secondary salt + GABA treatment was lower than that in the secondary salt treatment. The results showed that in cotton seedlings that were not stressed, the POD activity was stable. When stressed, the cotton seedlings would activate their own defense mechanism to resist damage, and GABA helped to increase the POD activity.

[0088] Regarding the MDA content test results, according to Tables 1 to 2 and Figures 15-16 It can be seen that the MDA activity of Xinluzhong No. 22 and Xinluzhong No. 42 in CK treatment, GABA treatment and VGB treatment did not change significantly during the 0-48h stress. The MDA activity of other treatments increased in 0-8h, decreased in 8-12h, and increased in 12-48h. After secondary salt treatment, the application of GABA can significantly reduce the MDA activity, and the application of VGB treatment significantly increased the MDA activity. The MDA activity of GABA treatment in both varieties was lower than that of other treatments. The results show that GABA can reduce the MDA activity of cotton.

[0089] Regarding the CAT activity test results, according to Tables 1 to 2 and Figures 17-18 It can be seen that with the increase of stress time, except for CK, GABA, and VGB treatments, the CAT activity of other treatments showed a trend of first increasing and then decreasing, and the CAT activity was the highest at 12h after stress. At 24-48h after stress, the CAT activity of secondary salt + GABA treatment, secondary salt + VGB treatment, and secondary salt treatment was lower than that of CK treatment. This may be because the stress caused some physiological disorders of cotton, resulting in the blockage of the enzyme synthesis pathway. The CAT activity of Xinluzhong No. 22 secondary salt + GABA treatment was higher than that of secondary salt treatment; the CAT activity of Xinluzhong No. 42 secondary salt + GABA treatment was higher than that of secondary salt treatment at 0-12h, and lower than that of secondary salt treatment at 12-48h. The results show that GABA can increase the activity of catalase under secondary salt stress, reduce the accumulation of harmful substances, and ensure the normal physiological metabolism of seedlings.

[0090] About O2 - Content test results, according to Table 1 ~ 2 and Figures 19-20 It can be seen that with the increase of stress time, the O2 - The content remained stable, while the other treatments showed an upward trend. The secondary salt treatment O2 -The results showed that when there was no stress, the O2 - The content tends to be stable, but changes significantly when secondary salt stress occurs. GABA can reduce O2 - content.

[0091] Regarding the H2O2 content test results, according to Tables 1-2 and Figures 21-22 It can be seen that the H2O2 content of the two varieties in the CK treatment, GABA treatment and VGB treatment did not change significantly, and the H2O2 content of the other treatments increased in 0-8h, decreased in 8-12h, and increased in 12-48h. The H2O2 content of the two varieties in the secondary salt + GABA treatment was lower than that in the secondary salt treatment. The results show that GABA can reduce the H2O2 content under secondary salt stress.

[0092] Regarding the soluble protein content test results, according to Tables 1-2 and Figures 23-24 It can be seen that with the increase of stress time, except for the CK treatment, the soluble protein content of Xinluzhong No. 42 showed a trend of first increasing and then decreasing; the soluble protein content of Xinluzhong No. 22 showed a trend of first increasing and then decreasing, and then increasing again. The soluble protein content of the two varieties in the GABA treatment and secondary salt + GABA treatment was significantly higher than that in the CK treatment and secondary salt treatment. Within the 12-48h stress period of Xinluzhong No. 42, the soluble protein content of the secondary salt treatment was lower than that of the CK treatment, and within the 24-48h stress period of Xinluzhong No. 22, the soluble protein content of the secondary salt treatment was lower than that of the CK treatment. The results show that GABA can increase the soluble protein content of cotton.

[0093] It can be seen from the above content that the technical solution provided by the present invention can alleviate the saline-alkali stress of cotton and is not restricted by seasons or affected by external climate.

[0094] 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. The application of γ-aminobutyric acid in alleviating saline-alkali stress of cotton, characterized in that: The saline-alkali stress is secondary salt solution stress; The salt content of the secondary salt solution is 0.45% to 0.47%, and the pH value is 7.5 to 8.

0.

2. The use according to claim 1, characterized in that: The gamma-aminobutyric acid alleviates cotton saline-alkali stress by one or more of increasing cotton superoxide dismutase activity, increasing cotton peroxidase activity, reducing cotton malondialdehyde content, increasing cotton catalase activity, reducing superoxide anion content, reducing cotton H2O2 content and increasing cotton soluble protein content.

3. The use according to claim 1, characterized in that: The cotton includes Xinluzhong No. 42 and / or Xinluzhong No.

22.

4. The use according to claim 1, characterized in that: The secondary salt solution includes components with the following concentrations: NaHCO3 0.72-0.73 g / L, NaSO4 20.03-20.04 g / L, K2SO4 1.68-1.69 g / L, MgSO4·7H2O 14.34-14.38 g / L, and CaCl2 10.76-10.77 g / L.

5. The use according to any one of claims 1 to 4, characterized in that: The usage ratio of the γ-aminobutyric acid to the secondary salt solution is 0.51-0.52 g:1L.

6. A method for alleviating saline-alkali stress in cotton, characterized in that: Cultivating cotton seedlings after adding GABA to secondary salt solution; The salt content of the secondary salt solution is 0.45% to 0.47%, and the pH value is 7.5 to 8.

0.

7. The method according to claim 6, characterized in that The usage ratio of the γ-aminobutyric acid to the secondary salt solution is 0.51-0.52 g:1L.

8. The method according to claim 6 or 7, characterized in that: The secondary salt solution includes components with the following concentrations: NaHCO3 0.72-0.73 g / L, NaSO4 20.03-20.04 g / L, K2SO4 1.68-1.69 g / L, MgSO4·7H2O 14.34-14.38 g / L, and CaCl2 10.76-10.77 g / L.

9. The method according to claim 6, characterized in that The cultivation method is hydroponics; The culture conditions are: ambient temperature 28°C, humidity 85%, 16 / 8h light; The culture time is 4 to 48 hours.

10. The method according to claim 6, characterized in that The cotton seedlings are at the three-leaf stage.

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