拟南芥低叶绿素荧光LCF3基因的克隆与功能分析

摘要

叶绿素荧光动力学技术在测定叶片光合作用中光系统对光能的吸收、传递、耗散、分配等方面具有独特的作用.本研究借助叶绿素荧光成像仪,从拟南芥EMS诱变突变体库中筛选到一株低叶绿素荧光突变体lcf3-1(lower chlorophyll fluorescence 3-1).遗传分析表明lcf3-1突变体为单基因隐性突变.突变基因图位克隆结果显示LCF3是PsbW的等位基因.另外,LCF3基因的T-DNA插入突变体及功能回补转基因植物的叶绿素荧光分析结果均证明LCF3基因突变导致拟南芥叶绿素荧光Fv/Fm值降低.进一步实验结果显示,LCF3蛋白定位于叶绿体,且LCF3基因在植株中普遍表达.PsbW蛋白可能细微调整PSII-LHCⅡ超复合体的组装及稳定.%Chlorophyll fluorescence has exclusive role for determining the kinetics of light energy absorption, transmission, dis-sipation and distribution in leaf photosynthesis. In this study, a mutant was screened by chlorophyll fluorescence equipment from EMS mutagenesis of wild-type Arabidopsis Col-0, which showed lower Fv/Fm than wild-type and was named lcf3-1(lower chlo-rophyll fluorescence 3-1). Genetic analysis of lcf3-1 mutant suggested that the mutation was controlled by single recessive gene. LCF3 gene, which encodes PsbW protein, wasisolated by map-based cloning. The T-DNA insertion mutant lcf3-2showed low chlorophyll fluorescence phenotype aslcf3-1,and this phenotype could be complemented by LCF3 gene of wild-type. These ex-periments implied that the phenotype of low-chlorophyll-fluorescence resulted fromLCF3 gene mutation. Furthermore, our re-sults indicated that LCF3 protein is located in chloroplast and LCF3 gene is expressed in various tissues. PsbW protein is impor-tant for the contact and stability between several PSII-LHCⅡ supercomplexes.