一个光敏色素B调控的水稻NBS-LRR基因的表达模式分析

Expression Patterns of One Phytochrome B-Regulated NBS-LRR Family Gene in Rice

利用水稻基因芯片比较野生型、phyA和phyB突变体受连续红光照射后的基因表达图谱,从中筛选到一个受光敏色素B(phyB)介导的红光信号特异诱导的、编码NBS-LRR类蛋白的基因,命名为PB-LRR(phyB-regu lated NBS-LRR)。为了揭示PB-LRR基因在水稻生长发育中的作用,对该基因表达的器官特异性及其对不同激素的应答反应进行了分析。结果表明,PB-LRR基因在叶中表达水平最高,在茎中最低。光对PB-LRR基因表达的诱导是由phyB调控的,与phyA无关。此外PB-LRR基因的表达受外源ABA的抑制,并且受环境因子的调控。构建PB-LRR启动区∶GUS植物表达载体,转化至野生型和phyB突变体中,GUS染色结果表明,在phyB突变体转基因植株中的GUS活性明显低于野生型,而且GUS活性主要出现在叶片上部。这表明PB-LRR基因的表达不仅受phyB介导的光信号调控,而且受发育调控。本研究结果为进一步分析PB-LRR基因在phyB介导的光反应和水稻抗病反应中的作用奠定了基础。

The gene named PB-LRR（phyB-regulated NBS-LRR） encoding NBS-LRR family protein and up-regulated by red light perceived by phyB was obtained by comparing the gene profiles among wild type,phyA and phyB mutants exposed to continuous red light.To access the biological functions of PB-LRR gene in rice,the organ specificity of its expression was analyzed as well as its response to exogenous hormones.The expression level of PB-LRR gene was the highest in leaf and the lowest in stem.The light-induced expression of PB-LRR gene was attributed to phyB,but not phyA.Moreover,the expression of PB-LRR gene was inhibited by exogenous ABA,and also regulated by environmental factors.The expression vector of PB-LRR promoter region and GUS（ProPB-LRR∶GUS） was constructed and introduced into wild type（WT） and phyB mutant,respectively.The results showed that the GUS activity in transgenic phyB mutant was obviously lower than that in wild plant,and emerged mainly in the upper part of leaves.All these results demonstrated that PB-LRR gene was not only regulated by phyB-mediated light signals but also by leaf development in rice.This study provided basis for further research on the roles of PB-LRR in phyB-mediated photoreaction and disease resistance in rice.