Cloning And Function Analysis Of Promoters Of PGIP Gene Family From Different Disease Resistant Apple (Malus Domestica Borkh)

In this study, different disease resistant apple varieties Qinguan, Pacific Rose and Hokutowere chosen as test materials. And their PGIP1gene and PGIP2gene promoters were cloned.The differences of these promoters sequences and activities were compared; for furtherresearch of PGIP2gene promoters which showed different activities in different applecultivars, different element deleted promoters and GUS gene expression vectors of QinguanPGIP2gene promoter were constructed, and their activities were tested in the way ofmeasuring reporter gene GUS expression in tobacco leaves by the method ofAgrobacterium-mediated transformation, and by comparing their activities differences theresponsive elements of different induction conditions were screened and the mechanism ofresistance PGIP differences in gene expression were discussed. The main conclusions were asfollows:1.2PGIP genes’ upstream2000~2300bp promoters of Malus domestica Borkh. cv.Qinguan, Pacific Rose and Hokuto were cloned. Their PGIP1promoters shared a consistencyof99.72%, and from-385bp to-1bp segment the sequences were entirely consistent, whilePGIP2promoters shared a consistency of99.36%, and the entirely consistent sequence areawas from-886to-1. The two PGIP genes promoters consistencies of three cultivars were79.61%,79.33%and79.4%respectively. Cis-elements prediction results showed that PGIP1gene promoters contained methyl jasmonate-responsive elements, while PGIP2genepromoters owed salicylic acid responsive elements. According to promoter elements predicted,it was speculated that these promoters had promoter structural features; PGIP1genepromoters had200、202and200elements respectively while PGIP2gene promoters owned183、180and180elements respectively; PGIP1gene promoters contained methyljasmonate-responsive elements, while PGIP2gene promoters owed salicylic acid responsiveelements.2. The6promoters from three cultivars all had promoter activity and could drive GUSgene expression in the plant cytoplasm and nucleus. Among different species, and the activityof Qinguan PGIP2promoter were significantly higher than Pacific Rose (P <0.05), while it’snot significantly higher than Hokuto. In the same species, PGIP1gene promoter activity was significantly higher than PGIP2.3. After darkness and wounding treatment, Qinguan PGIP1promoter activity reducedwhile Qinguan PGIP2promoter activity increased; that PGIP1gene promoter regionof-2104~-1824bp and PGIP2gene promoter region of-1313~-1070bp may play an importantrole in regulating gene transcription; that PGIP1gene promoter region of-144~-1bp andPGIP2gene promoter region of-37~-1bp maybe the key region of inducible gene expression.