Synthetic Of Glutathione S-transferase Gene From Tomato (Lycopersicon Esculentum M.) And Functional Of Genes

Plant glutathione S-transferases (GSTS) play an important role in plant stress responses and growth development. They can not only remove toxic metabolites of external toxin and internal,but also have peroxidase activity that remove hyroxyl peroxide toxicity.In this experiment, we chemically synthesized the glutathione S-transferase gene in Lycopersicon esculentum Mill based on the amino acid sequences released on the NCBI.We optimize the nuclear sequence by removing sequences to form stem-loop structure and hairpin structure and reverse repeats sequences and transcription termination signal, avoiding the 3’end exists complementary sequence, rich in GC and error matching, designing 5’end and middle domain for G or C primers, designed two primers, that Tm value difference should not be greater than 5℃.The synthesized gene, named LeGSTU2 was transferred into wild Arabidopsis thaliana by agrobacterium floral dip method.We treated the transgenic type and wild type with different concentrations of NaCl and mannitol solution of salt and drought stress on seeds, seedlings and plants.Experimental results showed that there were obvious differences in the transgenic type and wild type to salt and drought treatment.In particular,under the condition of normal growth,GST activity of the transgenic type was obviously higher than that of wild type. Comparison the seed germination rate percentage and root long between the transgenic type and wild-type, we found that the inhibition of high salt and drought stress on transgenic plants is significantly lower than wild-type.Under salt and drought stress treatment,the survival of transgenic plants was significantly higher than that of the wild type.Standard moisture content,transgenic plants showed higher hold water than that of wild type.Moreover, under salt stress(250mM NaCl)treatment,the changes of proline, malondialdehyde and chlorophyll contents intuitional explained the transgenic type plants have stronger tolerance on high salinity. All these results showed that,under high salt and drought stress, the LeGSTU2 over-expressing transgenic plants exhibited more resistance to salt and drought stress than wild-type plants.