水、旱稻差异表达抗旱候选基因的序列分析

Sequence analysis of drought-tolerance related genes differentially expressed in lowland and upland rice

为研究在水、旱稻差异表达的抗旱候选基因、解释旱稻抗旱的分子机理,本研究选取已获得的水、旱稻干旱胁迫处理基因表达谱中在旱稻中高表达的候选基因,对其编码区和启动子区进行测序分析,以期比较可能的抗旱相关基因在水、旱稻基因组水平上的异同。根据水、旱稻差异表达结果,筛选出8个旱稻高表达基因。通过测序分析发现7个基因在水、旱稻间没有差异,只有一个候选基因OsMIP在典型水稻(日本晴、越富)和典型旱稻(IRAT109、毫格劳)启动子区之间存在18个SNP和1个Deletion的序列差异,说明在干旱胁迫下,旱稻高表达基因中只有少数存在序列上的差异。为进一步验证OsMIP的启动子区在水、旱稻间的序列差异,利用国内、外86份水、旱稻材料对该基因的启动子区进行测序分析,所得到的所有启动子序列可分为4种单倍型H1、H2、H3和H4,在单倍型H2中获得与抗旱相关的8个SNP和1个Indel,推测该基因的启动子区域的一个或多个序列差异可能是引起水、旱稻OsMIP基因差异表达的原因。

Selection of high expression genes in UR being potential drought resistant genes was performed in order to study the high expression molecular mechanism in UR. The coding region and promoter sequence of each candidate gene were analyzed to compare differences of the genome in drought-related gene. In this study,eight highly expressed genes in UR were selected in UR according to the previous results. The sequencing results showed that there was no differences among seven of the eight candidate genes, but one gene, OsMIP, had differences with 18 SNPs and one deletion in its promoter region between the LR （Nipponbare and Yuefu） and UR （IRAT109 and Haogelao）. It suggested that only minority sequence differences existed in the drought-tolerance related genes which differentially expressed in UR and LR （highly expressed in UR） under the drought stress. Further sequence analysis with 86 varieties from local and abroad identified four haplotypes （H1, H2, H3 and H4） . In the H2 haplotype, eight SNPs and one Indel in OsMIP promoter region were novel in UR. So,these SNPs and deletion may be related to drought tolerance thus may cause the genes expressed differently in UR and LR.