番茄叶绿体外膜转运蛋白(TOC复合体)组分鉴定、基因克隆与弱光胁迫下表达分析  

Composition identification,gene cloning and expression analysis of the translocon of the outer membrane of chloroplast(TOC complex)in tomato under low light

作　　者：王琪[1,2] 闫见敏 岳江[1,2] 李云洲 须文 WANG Qi;YAN Jianmin;YUE Jiang;LI Yunzhou;XU Wen(College of Agriculture,Guizhou University,Guiyang 550025,China;Vegetable Research Institute,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州大学农学院,贵阳550025 [2]贵州大学蔬菜研究院,贵阳550025

出　　处：《植物生理学报》2022年第2期294-308,共15页Plant Physiology Journal

基　　金：国家自然科学基金(31960604);贵州省自然科学基金(黔科合基础[2019]1107号,黔科合基础-ZK[2021]重点040);贵州大学人才引进科研项目(贵大人基合字[2014]18号);贵州省生物学国内一流学科建设学科开放基金(GNYL[2017]009FX4KT43)。

摘　　要：叶绿体外膜转运蛋白(translocon of the outer membrane of chloroplasts,TOC)介导了数千种位于细胞质中由细胞核编码的前体蛋白的识别与初始转运,对叶绿体生物合成及正常行使生物学功能具有重要作用。为明确番茄TOC复合体组分及其表达特性,本研究基于番茄(Solanum lycopersicum)全基因组数据对番茄TOC复合体进行组分鉴定,并对其染色体定位、基因结构、保守基序、系统进化及弱光胁迫下表达模式等进行了分析。结果表明,番茄基因组中鉴定到10个TOC组分,分布于8条染色体上,分为4个基因家族,同一家族中的成员具有相似的基因结构和基序。e Plant提供的组织表达数据显示,TOC复合体不同组分在番茄中的表达具有组织特异性。qRT-PCR分析发现,番茄果实成熟过程中TOC复合体组分基因表达水平高于叶片组织,在这一过程中SlToc34-1、SlToc159-1和SlToc75表达上调,SlToc34-2、SlToc159-2和SlToc120表达下调;弱光胁迫处理下SlToc159-2、SlToc34-1和SlToc120表达水平均受到抑制,SlToc159-1和SlToc34-2没有明显的变化。研究成功克隆了SlToc159-2、SlToc34-1和SlToc34-2基因的cDNA序列,它们的氨基酸推导序列与拟南芥TOC组分蛋白具有很高的同源性,表明番茄是一种新的研究TOC复合体的有效模式植物。本研究为进一步探究番茄TOC复合体组分的功能提供参考。The translocon of the outer membrane of chloroplasts(TOC)mediates the recognition and initial transport of thousands of precursor proteins encoded by the nucleus in the cytoplasm.It plays an important role in chloroplast biosynthesis and normal biological function.In order to clarify the components and expression characteristics of tomato TOC complex,this study identified the components of tomato TOC complex based on the whole genome data of tomato(Solanum lycopersicum),and analyzed its chromosomal location,gene structure,motif,phylogenetic evolution and expression pattern under low light stress.The results showed that 10 TOC components were identified in tomato genome,distributed on 8 chromosomes and divided into 4 gene families,and members of the same family had similar gene structure and motif.The tissue expression data provided by ePlant showed that the gene expression of each component of TOC complex was tissue specific in tomato.qRT-PCR analysis showed that the gene expression levels of all components of TOC complex in tomato fruit ripening were higher than that in leaf tissue.SlToc34-1,SlTOC159-1 and SlToc75 were up-regulated,while SlToc34-2,SlToc159-2 and SlToc120 were down-regulated.SlToc159-2,SlToc34-1 and SlToc120 expression levels were down-regulated under low light stress,and SlToc159-1 and SlToc34-2 showed no significant changes.The cDNA sequences of SlToc159-2,SlToc34-1 and SlToc34-2 genes were successfully cloned.The deduced amino acid sequence analysis showed that tomato TOC had high homology with TOC component proteins of Arabidopsis thaliana,indicating that tomato is a new effective model plant for studying TOC complex.The results provide reference for further study on the function of TOC complex components in tomato.

关 键 词：番茄 叶绿体外膜转运蛋白 TOC复合体 全基因组鉴定 基因表达 基因克隆 

分 类 号：S641.2[农业科学—蔬菜学]