Salt Tolerance Analysis Of A 2-Cys Prx Gene From Tamarix Androssowii

Improvement and utilization of saline is one of the important and positive measures to improve the salt tolerance of plants. With the development of molecular biology, genetic engineering is an effective way to improve salt tolerance in plants. To determine the function of 2-Cys Prx gene from Tamarix androssowii, We used yeast and tobacco as model organisms to make a preliminary study in the present study. The results are as follows:The time-course expression pattern of 2-Cys Prx gene was investigated under abiotic stress conditions by real-time RT-PCR. The results showed that 2-Cys Prx was resonse to treatments of PEG,NaHCO3,NaCl,CdCl2 and ABA, and had tissue specific expression pattern.The 2-Cys Prx gene was inserted into the yeast expressive vector pYES2, the recombinant plasmid (pYES2-2-Cys Prx) was transformed into Saccharomyces cerevisiae INVSc1 to characterize the tolerance of 2-Cys Prx to different abiotic stresses. The results demonstrated that 2-Cys Prx exhibits multiple abiotic stess tolerance, including salt, alkali, drought, heat, cold, oxidative and heavy metal stress.To further characterize 2-Cys Prx's function under salt and oxidative stress, we obtain transgenic tobacco for 2-Cys Prx gene from Tamarix androssowi..Six transgenic lines were selected for the test of NaCl and Methyl viologen tolerance. CAT activity was measured under the two sresses. The results showed that CAT activity in most transgenic lines was higher than in non-transgenic tobacco under NaCl or Methyl viologen conditions. In addition, germination rate and relative growth were subsequently compared between first generation of transgenic and non-transgenic tobacco. Results showed that the most transgenic lines exhibited germination rate and relative growth than non-transgenic tobacco. It illustrates that overexpression of 2-Cys Prx gene can increase transgenic tobacco salt and oxidative stress.To determine the proteins which could interact with 2-Cys Prx from Tamarix androssowi., the 2-Cys Prx gene was constructed to the Bait vector. The proteins interacted with 2-Cys Prx were screened using yeast two-hybrid system. Twelve proteins that interacted with 2-Cys Prx were detected. Seven of them were unknown proteins, five of them were known proteins. The five known proteins were alanine--glyoxylate aminotransferase 2,malate dehydrogenase,flavonol synthase,peptidyl-prolyl cis-trans isomerase and expansin. The interaction of 2-Cys Prx and those proteins indicated that 2-Cys Prx participates in enzymatic metabolism of photorespiratory,several metabolic pathways involving both catabolic and anabolic activities,extension and stress relaxation of plant cell walls and folding of new polypeptide chain to regulate the capacity of auxin and resistance of pathogen infection.however, the detailed process and the functional significance of their interaction need to be further studied.