Abstract:Based on the RNAseq data of Pb2+induced tartary buckwheat leaves, we cloned a phytochelatin synthase gene (FtPCS) from Fagopyrum tataricum using the RTPCR method. The FtPCS gene was subcloned into pET28a(+) using Infusion technology, which was expressed in Escherichia coli BL21 Star(DE3). Being applied with Pb2+, the catalytic activity of the purified FtPCS protein was detected by reverseHPLC involving DTNB (5,5′dithiobis2nitrobenzoic acid) postcolumn derivatization method. The results indicated that the full length of genomic sequence of FtPCS was 5 456 bp, containing 8 exons and 7 introns; the CDs sequence of FtPCS was 1 485 bp in length, which encoded a 55.10 kDa protein consisted of 494 amino acids. The FtPCS was highly expressed in E.coli in the form of inclusion body, which was refolded by dialysis and purified by Co2+ chelation chromatography. The purified FtPCS recombinant proteins still kept the biological activity for transforming GSH to PC compounds, and the low concentration of Pb2+ could remarkably increase its catalytic activity.