Expression Of A Putative Na～+/H～+ Antiporter Gene PeNhaD1 In E.coli And Saccharomyces Cerevisiae

In this research, in order to testify the function, study the expression and cellular localization of the putative Na+/H+ antiporter gene PeNhaD1 of Populus euphratica Oliv., we expressed PeNhaD1 in Escherichia coli and Saccharomyces Cerevisiae respectively.A complementary study was carried out to determine the function of PeNhaD1 in salt resistance. PeNhaD1 was introduced to the S. cerevisiae mutant strains ANT3 (?ena1-4::HIS3 ?nha1::LEU2) and GX1 (?nhx1::TRP1), which lacks the yeast plasma membrane Na+/H+ antiporter gene ScNHA1 and tonoplast Na+/H+ antiporter gene ScNHX1, respectively. Compared with controls, PeNhaD1 gene-transferred mutant strains ANT3 (ANT3-PeNhaD1) was more tolerant to the salt under the condition of 80 mM NaCl, pH 6.0. However, the increased salt resistance was not observed in PeNhaD1 gene-transferred mutant strains GX1. The result suggests that PeNhaD1 may maintain the capacity for salt exclusion under saline conditions, contributing to the salt tolerance of Populus euphratica.At the same time, we constructed two E. coli expression vectors PTAC-GFP and PTAC-PeNhaD1-GFP, which carried the GFP gene and PeNhaD1-GFP combined gene respectively. After been induced by 0.4mM IPTG (for 2~4h) and expressed in BL21 (DE3), the result of SDS-PAGE, Western-Blotting shows that GFP has been successfully expressed in BL21 (DE3) but PeNhaD1-GFP been failed. We also tried to express...