拟南芥PRRs基因在红光和蓝光信号转导中的作用初探

以拟南芥为材料,在红光和蓝光下对PRRs(pseudo-response regulators)突变体prr5p、rr7、prr9和toc1及其野生型的下胚轴表型进行比较观察,并采用实时定量PCR方法对突变体中光信号通路相关基因ZTL(zeitlupe)和CO(constans)的节律表达进行分析.结果表明:在红光下,prr5和toc1的下胚轴长度比野生型显著增长,在蓝光下,prr7p、rr9和toc1较野生型短,表明突变体降低了拟南芥对红光的敏感性,却增强了对蓝光的敏感性.红光和蓝光下,PRRs突变体中ZTL和CO的mRNA节律表达与野生型明显不同,其中红光下prr5和prr7、蓝光下prr5和toc1中的ZTLmRNA的表达显著下降且节律消失;红光下prr7和prr9以及蓝光下prr5突变体中的COmRNA表现基本无节律.因此推测,PRRs与ZTL的相互作用很可能在红光和蓝光信号转导途径中发挥作用,且PRRs基因极有可能参与了红光和蓝光对CO的调控.

Effect of PRRs Genes on Signal Transduction of Red Light and Blue Light in Arabidopsis thaliana

The null mutants in Arabidopsis thaliana PRRs(pseudo-response regulators) family(prr5,prr7,prr9,toc1) and wild type were used to study the hypocotyls length changes under red light and blue light.And corresponding expressions rhythm of light signal transduction pathways associated genes ZTL(zeitlupe) and CO(constans) were analyzed by real-time quantitative PCR.Compared with the wide type,the hypocotyls length of the prr5 and toc1 mutants significantly increased under red light,while under blue light the hypocotyls length of prr7,prr9 and toc1 shortened.The altered sensitivity to red light and blue light in elongation of mutant seedlings hypocotyls indicated that the PRRs might regulate the signal transduction of red light and blue light.Furthermore,the mRNA express rhythm of ZTL and CO in PRRs mutants were distinct from wild type under red light and blue light.The expression level of ZTL was apparently reduced and the rhythm was virtually abolished in prr5,prr7 under red light as well as in prr5,toc1 under blue light.The mRNA expression of CO was arrhythmic in prr7,prr9 under red light and in prr5 under blue light.So we presumed that the PRRs-ZTL interaction may play a role in the red light and blue light signal transduction pathway and PRRs participate in the modulation of red light and blue light on CO expression.