Cloning, Expression And Bioinformatic Analysis Of Polygalacturonase Inhibiting Protein Gene Bnpgip2-1in Nape

Ploygalaturonase inhibiting proteins (PGIPs) are anti-fungal proteins with leucine-rich repeat (LRR) in many plants, which could inhibit the catalytic activity of fungal endo-PG, localized in the plant cell wall, and play an important role in the plant resistance to pathogenic fungi.In this study, gene Bnpgip2-1encoding BnPGIP2-1in nape was cloned by PCR. The sequence and structure of BnPGIP2-1were infered by biological information analysis and its inhibition to the activity of Sclerotinia sclerotiorum PG was surveyed. Furthermaore, Bnpgip2-1expression in E. coli and its expression induced by the pathogen inoculation and the trentment of salicylic acid (SA), jasmine (JA) were studied. The detailed results are as follows:1. Bnpgip2-1was a sequence of1068bp with intron of76bp, which encodes a protein of331amino acids with signal peptide and10LRR. It was deduced that theoretical molecular weight was36.99kDa and pI value was8.04.2. The recombinant plasmid pET-Bnpgip2-1with ORF of Bnpgip2-1was constructed. Then, it was transferd into strain BL21of E. coli and expressed in the induction of IPTG. It was indicated that BnPGIP2-1expressed was about36.7kDa by SDS-PAGE, which was consistent with the deduced protein in the molecular weight. Most of the expressed protein lay in the inclusion body of E. coli. BnPGiP2-1could obviosly inhibit the reductive capacity of S. sclerotiorum PG.3. In these studies, Bnpgip2-1in rape variety D52was markedly induced by S. sclerotiorum infection and SA treatment, but not by JA.