苹果PGIP基因部分家族成员启动子的克隆与功能分析

Cloning and Function Analysis of Part of PGIP Gene Family Member Promoters from Apple

根据已发表的苹果基因组序列设计特异引物,克隆了苹果(Malus×domestica Borkh.)品种‘秦冠’和‘太平洋玫瑰’中PGIP家族基因PGIP1和PGIP2的启动子片段,序列分析结果表明PGIP1与PGIP2启动子序列相似度为71%,‘秦冠’和‘太平洋玫瑰’的PGIP1、PGIP2启动子相似度都达到了99%。两个品种PGIP1启动子中TATA-box和CAAT-box的数量明显多于PGIP2,PGIP1和PGIP2启动子分别存在茉莉酸甲酯和水杨酸响应元件,暗示PGIP1和PGIP2存在不同的抗病响应途径。构建了启动子︰︰GUS融合表达载体,通过对农杆菌介导法转化烟草叶片中的GUS活性分析,比较了不同启动子的活性。结果表明:PGIP1启动子活性在品种间差异不显著;PGIP2启动子活性在品种间差异显著,‘秦冠’是‘太平洋玫瑰’的2.37倍,可能与品种抗病性差异有关;同一品种中PGIP1启动子活性显著高于PGIP2。

Primers were designed according to the published sequence of the apple genome and two PGIP gene promoters of Malus× domestica Borkh.‘Qinguan'and‘Pacific Rose'were cloned. PGIP1 were 71% homology with PGIP2 gene promoters in both apple cultivar;Both PGIP1 and PGIP2 gene promoters of‘Qinguan'and‘Pacific Rose'shared a sequence identity of 99%. PGIP1 promoters had more TATA-box and CAAT-box than that of PGIP2 promoters,and PGIP1 gene promoters contained methyl jasmonate-responsive elements,while PGIP2 gene promoters owed salicylic acid responsive elements. It's speculated that there are different disease response pathways of PGIP1 and PGIP2. PGIP promoter activity were evaluated by promoter︰︰GUS fusion expression in transgenic tobacco leaves and the results showed that the PGIP1 promoters activity was not significant between cultivars while PGIP2 promoter of‘Qinguan'was higher than that of‘Pacific Rose',and the former's activity was 2.37 folds of the latter,which was probably related to the resistance difference. In the same apple cultivar,PGIP1 gene promoters' activities were significantly higher than that of PGIP2.