Glycerol-3-phosphate Levels Are Associated With Salt And Drought Stresses Response In Arabidopsis

Salt and drought stresses are the main factors which lead to decline of agricultural yield and quality. Understanding the mechanism that response to salt and drought stresses in plants has an important role in increasing resistance to salt and drought stresses, and ensuring agriculture peoducts with high yield, stable yield, and high quality.Many intermediates involved in the process of synthesis and metabolism of oil in plants are asscociated with response to biotic and abiotic stress. Glycerol-3-phosphate is a very important intermediate in oil metabolism, and it is an significant signal molecules to induce plant systemic immune. But the role of glycerol-3-phosphate is not yet researched in the process of abiotic stress. The study utilize mutants which can inhibite synthesis of glycerol-3-phosphate and cause accumulation of glycerol-3-phosphate as the materials, and wild-type Arabidopsis as control to study the relationship between glycerol-3-phosphate synthesis and salt or drought stress in Arabidopsis thaliana. The results shows that:(1) In the condition of adding exogenous NaCl, the germination rate of actl which can accumulate G3P is higher than wild type and the root length of actl has little difference than the wild type; at the same time the germination rate of mutants (cyt, glyl and gpdh3) resulting in a decrease levels of G3P is lower than the wild type, and the root length is shorter than wild type. These results indicate that G3P accumulation is contributed to the tolerance to salt stress and drought stress. The result that mannitol analog drought stress is resemble to the result of adding exogenous NaCl. Accumulation of G3P can enhance tolerance to salt and drought stresses in Arabidopsis thaliana.(2) Arabidopsis grown4weeks is treated without water about28days, and rewater about three days, then we found that the mutant glyl cannot resurrection, and wild type can be restored. The result shows glyl isn’t able to tolerant to drought stress.(3) By using the method of QRT-PCR, we detect the genes expression of G3P synthesis and metabolism under the treatment condition with NaCl and mannitol, and the results showed that under the condition of NaCl treatment, the expression of the key gene related to G3P metabolism is lower than the control, and the gene expression related to G3P synthesis in Arabidopsis thaliana is higher than control. All of results showed that Arabidopsis thaliana can regulate the synthesis levels of G3P by regulating the key genes of G3P synthesis and metabolism to increase tolerance to abiotic stress.(4) The method of QRT-PCR detect the key genes expression of ABA-dependent pathway (RD29B, RD26, ABF3) and ABA-independent way (COR15A, ADH1, ABF2) in mutants which can accumulate and decrease the level of G3P. The results showed that the regulation pathway is very complex to response salt and drought stresses, and different genes of G3P synthesis and metabolism participateing in the abiotic stress is concerned about ABA-independent way and ABA-dependent way.