In recent years, with the application of chemical reagents such as chemical fertilizers, the salinization of the fields has become more and more serious. How to improve the salt resistance of plants, make rational use of saline alkali land and reduce the loss of salt damage to agricultural production has become a major issue of close attention. In recent years, betaine has become one of the research hotspots in plant resistance physiology.betaineThe regulation of salinity and alkalinity of plants is mainly through the following processes.

    First, maintain cell osmotic pressure: when subjected to saline alkali or water stress, a large number of organic osmotic regulators such as betaine are accumulated in the cytoplasm, while the inorganic osmotic regulators in the cytoplasm are mainly to help squeeze into the vacuole, so that the external environment of the cytoplasm and the intracellular vacuole) can maintain osmotic balance, thus avoiding the toxicity of high concentration inorganic ions in the cytoplasm to enzymes and metabolism. The accumulation of betaine in plants under salt stress is an important physiological phenomenon that is conducive to the growth of plants under salt stress, and its content is positively correlated with salt tolerance of plants.

    Second, protection against enzymes: Betaine has high solubility and no electrostatic charge. Its high concentration has no effect on many enzymes and other biological macromolecules, and even has a protective effect. Betaine can protect the cell membrane of sugarbeet root, prevent heat injury, and increase the temperature required for enzyme heat denaturation; It can protect the thylakoid membrane of spinach against freezing stress; Remove the toxicity of high concentration salt to enzyme activity; Prevent dehydration induced protein thermokinetic interference; It also has a good protective effect on aerobic respiration and energy metabolism. Betaine on psh  Peripheral multi skin has a stabilizing effect.

    Third, salt resistance persistence: Betaine can be rapidly synthesized and accumulated to a very high concentration in the body. It has no feedback inhibition in the biosynthesis reaction and produces NaOH. In 150  Among many metabolites, betaine is the best osmotic regulator, and exogenous betaine with very low concentration has a good effect. Proline accumulation is a temporary response of plants to stress, while betaine accumulation may be permanent or semi permanent. The slow metabolism of betaine indicates that the regulation of betaine metabolism is mainly determined by synthesis.

    Fourth, influence the distribution of inorganic ions: barley can accumulate betaine under salt stress. Bitian garoon  When studying mangrove plants that accumulate betaine, et al. Found that betaine can pass betaine  /  P  roline  Transport body. Liu Jun et al. Observed the alleviating effect of barley on salt stress by applying exogenous betaine. The results showed that betaine could reduce the degree of membrane lipid peroxidation and increase the root water content and fresh weight of Barley Seedlings under salt stress. Betaine treatment could significantly reduce na  Water ratio. Betaine can also convert ca2  +It may be important for the root system to resist salt damage. In addition, betaine can regulate stomatal movement, respiration and related gene expression under stress.