Application of exogenous melatonin to improvement of salt tolerance of ricinus communis
Through the pre -treatment of outerogenic melatonin for ramie, the problem of insufficient salt resistance under the salt coercion is solved, significantly improved the salt resistance of ramie, relieved the growth obstacles caused by salt coerous, and enhanced the resistance of resistance. Oxidation defense system.
Patent Information
- Application Number
- CN202411578675.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-07
- Publication Date
- 2025-01-24
AI Technical Summary
The salt stress caused by soil salinization has a serious impact on plant growth, and the prior art is difficult to effectively improve the salt tolerance of plants.
Through the pre -treatment of outer stems for ramie, the specific steps are for the fifth week of sowing in ramie, and the melatonin solution with a 150ml concentration of 100um/L is performed for one consecutive week.
Significantly improved the salt tolerance of castor, alleviated the decrease in photosynthesis and oxidative damage caused by salt stress, increased the content of proline, soluble sugar and soluble protein, enhanced the activity of antioxidant enzymes, and adjusted the content of inorganic ions. Reduced ion poisoning.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of plant protection, and in particular to application of exogenous melatonin in improving the salt tolerance of castor. Background Art
[0002] Soil salinization has become an increasingly common and serious ecological problem, which not only harms agricultural production and grassland ecosystems, but also inhibits global plant growth and productivity. With the over-exploitation of natural resources by humans, soil salinization has become more and more serious, and soil environmental problems are particularly prominent, so food security is also threatened. my country's saline-alkali land is mainly distributed in 23 provinces, municipalities, and autonomous regions, covering an area of about 6.67 million hectares. Among them, the saline-alkali soil in Northeast my country is characterized by high content of NaHCO3 and Na2CO3. In addition to being rich in high content of Na + In addition, it will also cause a high pH value, which is more harmful to plants, which greatly limits the application of vegetation in the Northeast. At present, how to utilize saline soil has become a difficult problem for environmental protection. The utilization of saline soil mainly includes two aspects: ① Reducing soil salinity to a level that plants can adapt to; ② In order to better adapt to the salt in the soil, improve the salt tolerance of plants. Planting salt-tolerant plants on saline soil can reduce the soil salt concentration to a certain extent, and improve the physical and chemical properties of saline soil by using plant root growth. Similarly, improving plant salt tolerance also has positive significance. Therefore, conducting research on the mechanism of plant salt tolerance and improving plant salt tolerance can provide an important theoretical basis for the rational development and utilization of saline soil.
[0003] Castor (Ricinus communis L.) is an annual or perennial herb of the genus Ricinus in the Euphorbiaceae family. It has strong adaptability, tolerance to barrenness, and tolerance to salinity and alkali. It can grow well in relatively harsh environments or severely polluted conditions, and shows good adaptability and tolerance to polluted environments. With the advancement of science and technology, the comprehensive utilization of castor has been continuously deepened, and the research on castor in ecological management has also developed from simple and low-efficiency to multi-level and high-efficiency, especially the research on its ecological adaptability and stress resistance mechanism under salt stress environment has been continuously deepened.
[0004] Melatonin (MT) is a low molecular weight indole compound with multiple physiological activities. It is considered to be a new endogenous plant hormone with trace amounts but pleiotropic activities, and plays a vital role in plant response to abiotic stress.
[0005] Improving the salt tolerance of castor by pretreatment with exogenous melatonin is low-cost, easy to operate, green and environmentally friendly, and has good economic benefits. The results obtained in this study are conducive to further revealing the salt tolerance mechanism of castor, strengthening the comprehensive development of castor, and making it better used in the utilization and improvement of saline soil. Summary of the invention
[0006] In view of the above problems, the purpose of the present invention is to provide an application of exogenous melatonin in improving the salt tolerance of castor. By pre-treating castor with melatonin, its salt tolerance is improved, providing a simple and efficient chemical control and regulation method for improving the salt tolerance of castor and using it to improve saline soil.
[0007] The present invention is achieved through the following technical solutions:
[0008] The invention provides application of exogenous melatonin in improving the salt tolerance of castor.
[0009] Furthermore, the application includes the following steps: in the fifth week after castor plant sowing, 150 mL of 100 uM / L melatonin solution is irrigated into the roots once every 24 hours for one week.
[0010] Furthermore, the preparation method of melatonin solution is as follows: melatonin is first dissolved in anhydrous ethanol and then diluted with water to make the concentration of melatonin solution 100uM / L.
[0011] Furthermore, the melatonin solution is prepared in the dark and applied within 1-2 hours after sunset.
[0012] Beneficial effects of the present invention:
[0013] The invention improves the salt tolerance of castor by using exogenous melatonin, which helps to strengthen the comprehensive development of castor and make it better applied in the utilization and improvement of saline soil.
[0014] Preferably, in the above application, the feature of improving castor-oil plant salt tolerance is significantly alleviating the decrease in castor-oil plant photosynthesis caused by salt stress.
[0015] Preferably, in the above application, the feature of improving castor-oil plant salt tolerance is significantly alleviating castor-oil plant oxidative damage caused by salt stress.
[0016] Preferably, in the above application, the feature of improving the salt tolerance of castor is significantly increasing the content of proline, soluble sugar and soluble protein in castor under salt stress.
[0017] Preferably, in the above application, the feature of improving castor-oil plant salt tolerance is significantly alleviating the activity of antioxidant enzymes in castor-oil plant caused by salt stress.
[0018] Preferably, in the above application, the feature of improving the salt tolerance of castor is to reduce the sodium ion content of castor caused by salt stress and increase the potassium, phosphorus, magnesium and calcium ion contents.
[0019] The invention applies exogenous melatonin to castor plants when the plants grow to the fifth week, and irrigates the roots with 150 mL of a 100 uM / L melatonin solution once every 24 hours for one week. The invention is convenient to apply, highly operable, with a small amount, simple steps, low cost, quick effect, safety and reliability. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 Effects of exogenous melatonin pretreatment on the photochemical efficiency of castor oil plant under salt stress. (A) Net photosynthetic rate (Pn). (B) Stomatal conductance (Gs). (C) Intercellular CO2 concentration (Ci). (D) Transpiration rate (Tr). (E) Maximum quantum yield of PSII (Fv / Fm). (F) Actual photochemical efficiency (ФPSII). (G) Non-photochemical quenching coefficient (NPQ). (H) Photochemical quenching coefficient (qP).
[0021] Figure 2 Effects of exogenous melatonin pretreatment on osmotic regulatory substances in castor oil plants under salt stress. (A) Proline (Pro) content. (B) Malondialdehyde (MDA) content. (C) Soluble sugar (SS) content. (D) Soluble protein (SP) content.
[0022] Figure 3 Effects of exogenous melatonin pretreatment on antioxidant enzyme activities of castor oil plants under salt stress. (A) Catalase (CAT). (B) Superoxide dismutase (SOD). (C) Peroxidase (POD). (D) Ascorbate peroxidase (APX).
[0023] The bars represent data from three independent biological replicates and are shown as mean ± SD. Statistical analysis was performed using analysis of variance followed by Duncan's multiple comparison test. The superscript lowercase letters of photosynthetic parameters differed significantly between samples (p < 0.05). Abbreviations: NS plants grown under normal soil conditions; NS + MT melatonin pretreated plants grown under normal soil conditions; SS plants grown under 150 mM salt stress soil conditions; SS + MT melatonin pretreated plants grown under salt stress soil conditions. DETAILED DESCRIPTION
[0024] The technical solution of the present invention will be described clearly and completely below in conjunction with the specific embodiments and drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0025] In the following examples, the instruments used without indicating the manufacturer are all conventional products that can be purchased through regular channels. The methods described are all conventional methods unless otherwise specified, and the raw materials used can be obtained from public commercial channels unless otherwise specified.
[0026] 1. Materials and Methods
[0027] Plant material and treatment
[0028] Experimental materials: The plant material for the test is castor 'Fenbi No. 10'. Select seeds with full grains and complete structure, soak them in 0.5% sodium hypochlorite (NaClO) solution for 10 minutes for disinfection, then rinse the seed surface with sterile distilled water, wipe off the excess water on the seed surface with absorbent tissue after rinsing, and dry them for later use.
[0029] Soil selection: Purchase farmland soil and measure the field water holding capacity of the farmland soil. Filter with a 5 mm sieve, and sterilize the soil with high pressure steam.
[0030] Potted plant test: Select the processed farmland soil and put it into plastic pots of uniform specifications according to the same mass. The whole test was carried out in a greenhouse with an average temperature of 25℃ and a light duration of 12h. In order to avoid mutual influence between the roots of the seedlings and ensure germination, 3 castor seeds were sown in the middle of each plastic pot and watered with an equal amount of distilled water every day.
[0031] Melatonin pretreatment was started after the fifth week after sowing. 150 mL of 100 uM / L melatonin solution was irrigated once at the root within 1-2 hours after sunset. The treatment was continued for one week and a control was set. One week later, 150 mM salt stress was applied. 300 mL of water was irrigated daily to keep the soil under 150 mM salt stress. The stress was continued for one week and a control was set. There were 4 treatments in total, namely, plants grown under normal soil conditions (NS); plants grown under normal soil conditions pretreated with melatonin (NS+MT); plants grown under salt stress soil conditions (SS); plants grown under salt stress soil conditions pretreated with melatonin (SS+MT).
[0032] Castor samples were sampled 24 hours after salt stress treatment. All samples were frozen in liquid nitrogen immediately after measurement and then stored at -80℃ for future use.
[0033] Gas exchange parameters determination:
[0034] Four to five fully expanded leaves were randomly selected from each pot of plants, and the net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs) and intercellular carbon dioxide concentration (Ci) of the first fully expanded functional leaf from the top of the plants downward were measured using the Li-6400 (LI-COR, USA) portable photosynthesis measurement system at a light intensity of 1000 μmol·m-2·s-1 and a leaf chamber temperature controlled at 25°C.
[0035] Calculation of water use efficiency:
[0036] The water use efficiency here refers to the amount of CO2 assimilated by plants or leaves for each amount of water transpired, that is, the ratio of photosynthetic rate to transpiration rate, expressed in μmolCO2·mmol -1 H2O means.
[0037] Determination of fluorescence parameters:
[0038] The fluorescence parameters of the first fully expanded functional leaf from the top of the plant were measured using a portable fluorescence instrument FMS2 produced by Hansatech, UK. Four plants were selected for each measurement, and each plant was measured three times. The experimental data were tabulated in average values.
[0039] Osmotic regulating substances determination
[0040] The proline content was determined by ninhydrin colorimetry. Under stress conditions, MDA is a lipid peroxidation product, and its content is often used to explain the degree of peroxidation. The malondialdehyde (MDA) content was determined by thiobarbituric acid method. The soluble sugar content was determined by anthrone colorimetry. The soluble protein content was determined by Coomassie brilliant blue staining.
[0041] Antioxidant enzyme activity assay:
[0042] Superoxide dismutase (SOD) was determined by the nitroblue tetrazolium (NBT) method, peroxidase (POD) was determined by the guaiacol method, catalase (CAT) was determined by the hydrogen peroxide method, and ascorbate peroxidase (APX) was determined by a specific kit.
[0043] Determination of inorganic ion content:
[0044] The samples were measured by inductively coupled plasma optical emission spectrometry (ICP).
[0045] Data analysis
[0046] Excel was used for data processing, SPSS25.0 was used for variance analysis, and a significant difference was considered when the p-value was less than 0.05. Excel2016, Origin2018 and R-4.0.3 were used for drawing.
[0047] 2. Results and Analysis
[0048] Effects of exogenous melatonin pretreatment on the photochemical efficiency of Ricinus communis under salt stress
[0049] Exogenous melatonin pretreatment stabilized the photosynthetic parameters and chlorophyll fluorescence parameters of castor oil plant under salt stress. Figure 1 Salt stress can reduce the photosynthesis of castor, while exogenous melatonin pretreatment can significantly improve the net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr) of castor. It can also reduce the non-photochemical quenching coefficient (NPQ) of castor, significantly alleviating the decline in castor photosynthesis caused by salt stress.
[0050] Exogenous melatonin pretreatment can increase the Pn, Gs, Ci, and Tr of castor, which were significantly increased by 30.00%, 74.89%, 33.11%, and 64.97% under normal soil conditions, and significantly increased by 37.86%, 72.74%, 46.80%, and 57.57% under salt stress. Chlorophyll fluorescence parameters can well reflect photosynthetic efficiency, especially the actual photochemical efficiency (ФPSII); and melatonin pretreatment can increase the ФPSII of castor, which can be significantly increased by 65.22% under normal soil conditions and 13.07% under salt stress, effectively alleviating the negative impact of salt stress. In addition, melatonin pretreatment has a certain promoting effect on the reduction of NPQ, which is reduced by 21.49% under normal soil conditions and 2.22% under salt stress. The above results showed that the photosynthesis and gas exchange rates were weakened under salt stress, but they could be alleviated by exogenous melatonin pretreatment, which stabilized the effects of photosynthetic parameters and chlorophyll fluorescence parameters of castor under salt stress.
[0051] Effects of exogenous melatonin pretreatment on osmotic regulatory substances in Ricinus communis under salt stress
[0052] In order to quantify the effects of salt stress on castor biochemical parameters, the proline (Pro) content, malondialdehyde (MDA) content, soluble sugar (SS) content, and soluble protein (SP) content were further determined and analyzed ( Figure 2 ). Compared with the control group, salt stress increased the MDA content and decreased the Pro, SS and SP contents, causing secondary oxidative stress and oxidative damage to castor. Exogenous melatonin pretreatment alleviated the oxidative damage of castor by significantly increasing the Pro, SS and SP contents and significantly decreasing the MDA content.
[0053] When plants are subjected to adverse stress, a large number of superoxide free radicals will be produced, causing membrane lipid peroxidation and producing MDA. Excessive accumulation of MDA will cause cross-linking and polymerization of macromolecules such as proteins and nucleic acids, leading to changes in the structure and function of cell membranes. Therefore, membrane lipid peroxidation is an important sign of plant cell membrane damage. Melatonin pretreatment can significantly reduce the MDA content of castor under salt stress, which is 16.54% and 19.42% lower than that without melatonin pretreatment, respectively, reducing the oxidative damage of castor. The accumulation of osmotic regulating substances is one of the important mechanisms for plants to survive under adversity. Melatonin pretreatment can increase the Pro, SS and SP contents of castor, which are significantly increased by 1.00, 0.54 and 0.02 times respectively under normal soil conditions, and 0.79, 1.81 and 0.13 times respectively under salt stress, effectively alleviating the negative effects of salt stress.
[0054] Effects of exogenous melatonin pretreatment on antioxidant enzyme activities in Ricinus communis under salt stress
[0055] When plants are subjected to abiotic stress, the metabolism of reactive oxygen species (ROS) and reactive nitrogen species (RNS) is altered. In the early stages of stress, low concentrations of ROS and RNS can act as signal molecules to participate in the regulation of plant growth, development, and stress response processes. As the stress continues, high concentrations of ROS and RNS accumulate, disrupting the redox homeostasis in plant cells and breaking the original dynamic balance in the body. Due to the accumulation of a large amount of reactive oxygen species in the cells, oxygen stress is generated, causing irreversible oxidative damage to macromolecules such as lipids, proteins, and nucleic acids, disrupting the metabolic process, and ultimately leading to plant cell death. Therefore, maintaining intracellular redox homeostasis is crucial to improving plant stress resistance. In order to remove excess reactive oxygen, the antioxidant enzyme system needs to be activated to regulate the enzyme and non-enzyme content to a balanced state. The activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) were further measured and analyzed ( Figure 3 ).
[0056] Effects of exogenous melatonin pretreatment on antioxidant enzyme activities in castor plants subjected to salt stress Figure 3 . Under salt stress, exogenous melatonin pretreatment significantly increased the activities of SOD, POD and APX by 16.65%, 17.03% and 62.32% respectively compared with the control group, reducing the oxidative damage of castor. The results showed that melatonin pretreatment increased the activities of SOD, POD and APX of castor, thereby enhancing its antioxidant capacity to cope with salt stress. Melatonin pretreatment can enhance the antioxidant defense system of castor and effectively reduce the degree of oxidative damage caused by salt stress.
[0057] Effects of exogenous melatonin pretreatment on inorganic ion content in castor oil plants under salt stress
[0058] The effects of exogenous melatonin pretreatment on the inorganic ion content of castor beans under salt stress are shown in Table 1. Inorganic ion content plays an important role in the salt tolerance mechanism of crop osmotic regulation. For example, potassium ions (K + ) is the most abundant cation in plants. It is not only a macronutrient necessary for plant growth and development, but also plays an important role in regulating ion balance, osmotic regulation, maintaining cell turgor pressure and protein synthesis. 2+ ) is not only important for maintaining the integrity and stability of plant cell membranes, but also has an important relationship with the salt tolerance of plants. Under salt stress, melatonin pretreatment can significantly reduce the sodium ion (Na + ) content, increase the phosphorus ion, magnesium ion, K + , Ca 2+ content, reduce ion toxicity, and alleviate the negative impact of salt stress on plant growth.
[0059] Compared with the control group, melatonin pretreatment significantly reduced the Na + The content of castor oil can be reduced by 34.27% under normal soil conditions and 39.89% under salt stress; it can significantly increase the Ca content of castor oil 2+ The content can be increased by 29.10% under normal soil conditions and 27.27% under salt stress.
[0060] Table 1 Effects of exogenous melatonin pretreatment on inorganic ion content in castor oil plants under salt stress
[0061]
[0062] Note: Different lowercase letters in the same index indicate significant differences at the P < 0.05 level
[0063] Note:Different lowercase letters under the same index indicate significant difference at the P<0.05level
[0064] Summarize
[0065] In the present study, exogenous melatonin pretreatment under salt stress effectively increased the electron cycle transfer rate, fluorescence quantum yield and photosynthetic rate in the photosystem, and helped CO2 accumulation. The salt tolerance of castor was improved by increasing the content of proline, soluble sugar, soluble protein and the activity of antioxidant enzymes (SOD, POD and APX). The oxidative damage of castor caused by salt stress was alleviated by reducing the MDA content. The osmotic regulation ability of castor was enhanced by adjusting the inorganic ion content, reducing ion toxicity, and alleviating the negative impact of salt stress on plant growth.
[0066] The results of the study showed that exogenous melatonin can improve the salt tolerance of castor, which is helpful to strengthen the comprehensive development of castor and enable it to be better applied in the utilization and improvement of saline soil.
[0067] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. Application of exogenous melatonin in improving the salt tolerance of castor.
2. The use according to claim 1, characterized in that The application includes the following steps: In the fifth week after castor planting, irrigate the roots with 150mL of 100uM / L melatonin solution once every 24 hours for one week.
3. The use according to claim 2, characterized in that: The preparation method of melatonin solution is as follows: melatonin is first dissolved in anhydrous ethanol and then diluted with water to make the concentration of melatonin solution 100uM / L.
4. The use according to claim 2, characterized in that , melatonin solution was applied in the dark.
5. The use according to claim 2, characterized in that , melatonin solution should be applied within 1-2 hours after sunset.