Functional Verification Of The Plasma Membrane Na~+/H~+Antiporter TaSOS1and Its Super Active Mutant Gene From Wheat

Salinity soil is an important land resource, widely distributed over the world and each year there is a rising trend. At present, the land resource is scarce, salinity land regard as a potential land resources, is particularly important for its development and utilization. But because of salt stress can lead to osmotic stress, ion damage, damage plants and inhibit their growth, so many crops can no longer grow on saline land, so cultivate salt tolerant crop varieties is an effective way to use the saline land. In this study, based on previous studies, the TaSOS1gene and TaSOSl mutant gene△974were transferred into the mutant yeast AXT3K and dicotyledonous plants wild Nicotiana benthamiana, respectively. Analyze its salt tolerance, further studies the mechanism of salt tolerance on plasma membrane Na+/H+antiporter TaSOSl from wheat, verify its salt tolerance capabilities. Finally, the major conclusions are:(1)By the aid of a yeast mutant AXT3K to study the Na+/H+transport function of wheat plasma membrane TaSOSl and△974gene. The results showed that over-expression TaSOSl genes and A974gene in yeast, through the promotion of Na+efflux and K+uptake to improve its tolerance to salt, but the salt tolerance of A974gene was significantly higher than TaSOS1genes.(2) Transferred TaSOSl and△974gene into tobacco, verify its salt tolerance. The results showed that over-expression of△974and TaSOS1gene increased its salt tolerance in tobacco. The germination rate, fresh weight, dry weight, root length, chlorophyll content, the number of flower and seed were significantly higher than the wild type under salt stress, and over-expression of△974also significantly higher over-expression TaSOSl.(3)Under salt stress compared with the wild type, transgenic tobacco increased the stability of cell membrane and moisture, cause the electrolyte leakage of A974transgenic tobacco leaves to be significantly less than TaSOSl transgenic tobacco, and TaSOSl transgenic tobacco also significantly smaller than wild-type tobacco.(4) Measuring the Na+and K+ion content of tobacco leaves and roots under different salt concentrations, the results showed that the TaSOSl and△974transgenic tobacco by promoting Na+ion efflux, K+ion uptake, Na+transport from root to leaf through the xylem, to improve salt tolerance in plants.