桃XTH家族基因鉴定及其在桃果实贮藏过程中的表达特性  

Genome-Wide Identification and Expression Analysis of XTH Gene Family in Peach Fruit During Storage

作　　者：郭绍雷 许建兰[1] 王晓俊 宿子文 张斌斌[1] 马瑞娟[1] 俞明亮[1] GUO ShaoLei;XU JianLan;WANG XiaoJun;SU ZiWen;ZHANG BinBin;MA RuiJuan;YU MingLiang(Institute of Pomology,Jiangsu Academy of Agricultural Sciences/Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement,Nanjing 210014;College of Horticulture,Nanjing Agricultural University,Nanjing 210095)

机构地区：[1]江苏省农业科学院果树研究所/江苏省高效园艺作物遗传改良重点实验室,南京210014 [2]南京农业大学园艺学院,南京210095

出　　处：《中国农业科学》2022年第23期4702-4716,共15页Scientia Agricultura Sinica

基　　金：江苏省重大新品种创制(PZCZ201727);现代农业产业技术体系建设专项资金(CARS-30)。

摘　　要：【目的】通过桃木葡聚糖内糖基转移/水解酶(xyloglucan endotransglucosylase/hydrolase,XTH)基因家族鉴定与不同肉质桃贮藏过程中相关基因的表达分析,发掘PpXTHs家族成员中参与桃果实软化的重要候选基因,为深入解析PpXTHs在果实采后贮藏过程中的功能研究奠定基础。【方法】根据XTH蛋白保守结构域Glyco_hydro_16 domain和XET_C domain,利用Hmmer 3.1软件对桃蛋白质数据库进行搜索,鉴定桃XTH基因家族成员;利用在线软件ProtParam预测其分子量、理论等电点等理化性质;利用在线分析工具Plant-mPLoc预测其亚细胞定位;MEGA11软件构建系统进化树;运用在线工具MEME对其保守motif进行分析,Tbtools呈现蛋白保守结构域和基因结构图谱;MapChart软件绘制基因在染色体上的分布图;利用实时荧光定量PCR(quantitative reverse transcription PCR,qRT-PCR)技术检测PpXTHs在不同肉质桃贮藏过程中的表达特性。【结果】在桃基因组共鉴定XTH基因家族成员27个,分布在7条染色体上。系统进化树显示,PpXTHs家族成员可分为祖先类群、Ⅰ/Ⅱ亚家族以及ⅢA和ⅢB亚家族。蛋白结构域分析显示所有PpXTHs成员均含有Glyco_hydro_16和XET_C两个蛋白保守结构域。qRT-PCR结果表明,属于ⅢB亚家族的PpXTH33随着溶质桃贮藏期延长,表达量上调,且表达量显著高于同期硬质桃贮藏过程的表达水平;PpXTH33克隆测序结果显示其CDS序列与桃参考基因组一致,长度为924 bp,编码307个氨基酸;激光共聚焦显微镜观察发现PpXTH33与GFP融合蛋白可能主要于细胞壁与细胞核上产生绿色荧光信号。【结论】桃27个PpXTHs家族成员蛋白结构均含有2个XTH蛋白保守结构域,不均匀分布在7条染色体上。PpXTHs在溶质桃和硬质桃贮藏过程中的表达特性显示,PpXTH33与桃采后果实软化密切相关。【Objective】The aim of this study was to identify members of the XTH gene family from peach, and to analyze the expression of PpXTHs in peach fruit with different textures during storage, which not only provided data for the research on the candidate PpXTHs involved in peach fruit softening, but also laid the foundation for further study on the PpXTHs function in peach fruit softening.【Method】The HMM profiles of the Glyco_hydro_16 domain and XET_C domain were used to search all XTH proteins with the Hmmer 3.1 software in the peach protein database. The molecular weight, theoretical isoelectric point and other physicochemical properties were then predicted by the online tool ProtParam. PpXTHs subcellular localization were predicted by the online software Plant-mPLoc. The MEGA 11 software was used to construct a phylogenetic tree. The online tool MEME was used to analyze conserved motifs, the conserved motifs, conserved protein domains and gene structure maps were draw by Tbtools.According to the PpXTH gene family location information, chromosome mapping was carried out with MapChart software. The expressions of PpXTHs in peach fruit with different textures during storage were monitored by qRT-PCR. 【Result】A total of 27PpXTH genes were systematically identified from peach, which were distributed on seven chromosomes. Based on the phylogenetic tree, the ancestral group, Ⅰ/Ⅰ subfamily,ⅢA subfamily and ⅢB subfamily were classified. In addition, according to the analysis of protein domains, all PpXTH gene family proteins had Glyco_hydro_16 and XET_C conserved domain. The results from qRT-PCR analysis showed that PpXTH33 belonging to the ⅢB subfamily was upregulated as the storage period increased in melting peach fruit, with the expression being markedly higher than that during the storage period of stony hard peach fruit. The positive clone sequencing was consistent with the coding sequence of the Prunus persica reference genome with a length of 924 bp for a 307 amino acid sequence. The PpXTH33 co

关 键 词：桃 果实软化 XTH基因家族 基因表达 亚细胞定位 

分 类 号：S662.1[农业科学—果树学]