The Eukaryotic Expression Of PGIP Gene And The Effect Of SA Induction On The Expression Of PGIP Gene In Apple Leaves

Polygalacturonase-inhibiting protein (PGIP) is a leucine-rich repeated cellwall bindingprotein present in many plants, it could specifically inhibit endo-PG activity secreted byfungus, prevent other pathogenic fungi secrete hydrolytic enzymes destroys the cell, andenhance plant disease resistance. Therefore research PGlP eukaryotic expression and plantexpression have significant meaning for the use of the PGIP gene and their encoded protein.With the materials of the PGIP gene cloning vectors, a series of variety eukaryoticexpression vectors were constructed and transferred into Pichia pastoris GS115byelectroporation and induced the expression of the target protein. With the material of'Qinguan' and 'Liquan Fuji Spur' apple plant, the effect of Salicylic acid (SA) induction onPGIP gene expression of apple leaves were studied. The main conclusions were as follows:1. With the template of PGIP cloning vector, four kinds of PGIP fragment with or withstart and stop codon were amplified by PCR Then they were cloned into Pichia pastorissecreted expression vector pPICZαB respectively by enzymatically digested connection.Through efficient electroporation, screening and identification, a total of42recombinantPichia pastoris strains were obtained and induced by1%methanol, analyzed by SDS-PAGE,only one strain transferred by PGIP fragments with start codon and without stop codonexpressed target protein. The molecular weight of expressed PGIP was about46kDa.2. Salicylic acid induction had long-term and short-term effect on the PGIP geneexpression in apple leaves. The PGIP gene expression level of different disease resistanceapple differed from the inducing concentration:0.1and0.01mmol/L SA treatment bothpromoted the PGIP gene expression of 'Qinguan' while in 'Liquan Fuji Spur'0.1mmol/L SAtreatment promoted the PGIP gene expression but the0.01mmol/L SA treatment inhibited theexpression.