Under Salt Stress Betaine Beet Photosynthesis And Antioxidant Capacity

A high level of salt is harmful to plant. The salt stress drops in crop yields. High levels of salt turn the natural soil into saline. The farmland area is decreased in acute. Currently, land salinize quickly. The area of saline is very large. So how to develop and utilize become more important. Salt stress mainly caused plant physiology water shortage. Water is indispensable reactant and catalysts to various physiological and biochemical reaction for plant. Therefore salt stress results in the plant lack of water. Various normal physiological and biochemical are inhibited. The antioxidant system of plant can not work normally. The cell is aged and dead because of oxidation. Currently, many evidences show that the betaine can improve the function of plant in salt resistant. Because the betaine can reduce the osmotic potential of cell. The hydropenia phenomenon in physiological is remittance. Secondly, betaine and proteins can be bound together. The protein structure is more stable. And the biological activities are more active.In this paper, it uses the hydroponic way to cultivate sugar beet. Two sugar beet cultivars with different salt tolerance were used to study the photosynthetic and antioxidant reaction response to salt stress and the glycinebetaine applied through leaves. The density of glycinebetaine is 8mmol/L. The density of salt is 280mmol/L. After the treat, it determines sugarbeets biomass, photosynthesis, the enzymes of antioxidant system. Through hydroponic way to cultivate for 21d, After the ninth day, we get sample once every four days to determinate. Through the analysis of the experiment, the results indicated that the sugarbeet 13092 was more tolerant to NaCl stress than 25 at the part of biomass, betaine content, leaf area, peroxidase, catalase, superoxide dismutase, the chloroplast coupling ATPase, photosynthesis, leaf malondialdehyde and conductivity superior performance, etc. thought foliar spraying exogenous glycinebetaine, it can effectively improve the salt tolerance. The exogenous glycinebetaine after pretreatment of the salt stress was better at biomass, leaf area, peroxidase activity, catalase activity and superoxide dismutase (SOD), ATPase activity of chloroplast coupling, photosynthesis, leaf malondialdehyde and conductivity all have improved considerably compared with controls of salt stress treatment. Through the glycinebetaine treatment group compared with controls, there was no significant difference at biomass. But peroxidase activity, catalase activity and superoxide dismutase (sod), chloroplast coupling of ATPase activity has increased. It showed that the 8mmol/L glycinebetaine has no negative effect to sugarbeet in the normal environment. And it can promote partial enzymes activity.These paper studies the impact of betaine on the photosynthesis and oxidation of sugarbeet under salt stress, provides certain practical basis to the research of salt-tolerance mechanism. It has certain directive significance to cultivating sugarbeet and other salt-tolerant crop work.