中国农业科学

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最新录用:桃XTH家族基因鉴定及其在桃果实贮藏过程中的表达特性

郭绍雷1,许建兰1,王晓俊1,2,宿子文1,2,张斌斌1,马瑞娟1,俞明亮1* #br#   

  1. 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
  • 出版日期:2022-08-21 发布日期:2022-08-21

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

GUO ShaoLei1, XU JianLan1, WANG XiaoJun1,2, SU ZiWen1,2, ZHANG BinBin1, MA RuiJuan1, YU MingLiang1* #br#   

  1. 1Institute of Pomology, Jiangsu Academy of Agricultural Sciences/Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Nanjing 210014; 2College of Horticulture, Nanjing Agricultural University, Nanjing 210095
  • Published:2022-08-21 Online:2022-08-21

摘要: 【目的】通过桃木葡聚糖内糖基转移/水解酶(xyloglucan endotransglucosylase/hydrolaseXTH基因家族鉴定与不同肉质桃贮藏过程中的表达分析,发掘PpXTHs家族成员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 domainXET_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软件绘置基因在染色体上的分布图;利用实时荧光定量PCR (quantitative real-time 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ⅢAⅢB亚家族;通过蛋白结构域分析显示所有PpXTHs成员均含有Glyco_hydro_16XET_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PpXTH33GFP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27PpXTHs家族成员蛋白结构均含有2XTH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,桃PpXTH33与桃采后果实软化密切相关。


关键词: 桃, 果实软化, XTH基因家族, 基因表达, 亚细胞定位

Abstract: 【ObjectiveThe aim of this study was to identify XTH genes family from peach, and to analyze the expression of PpXTHs in different texture peach fruit during storage, which not only provided data support for exploring the candidate PpXTHs involved in peach fruit softening, but also laid the foundation for further studying PpXTHs function in peach fruit softening.MethodThe 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 peach protein database. Then the molecular weight, theoretical isoelectric point and other physicochemical properties were predicted by online tool ProtParam. PpXTHs subcellular localization were predicted by online software Plant-mPLoc. The MEGA 11 software was used to construct phylogenetic tree. The online tool MEME was used to analyze conserved motif, and conserved protein domain and gene structure map were draw by Tbtools. According to the PpXTHs family gene location information, chromosome mapping was carried out in MapChart software. Then the expression of PpXTHs in different texture of peach fruit during storage were detected by qRT-PCR. ResultA total of 27 PpXTH genes were systematically identified from peach, which were distributed on 7 chromosomes. Based on the phylogenetic tree, ancestral group, Ⅰ/Ⅱ subfamily, ⅢA subfamily and ⅢB subfamily were classified. In addition, according to the analysis of protein domains, all PpXTHs gene family proteins had Glyco_hydro_16 and XET_C conserved domain. The results of qRT-PCR showed that PpXTH33 belonging to ⅢB subfamily was up-regulated with the extension of storage period in melting peach, and the expression was prominent higher than that in stony hard peach storage period. The positive clone sequencing was consistent with the CDS sequence of Prunus persica reference genome with the length of 924 bp coding 307 amino acid sequence. The PpXTH33 combined with GFP may mainly located in the cell wall and nucleus by confocal laser scanning microscopy. ConclusionAll 27 PpXTHs protein structures contained 2 highly XTH conserved domains and distributed on 7 chromosomes . The expression characteristics of PpXTH33 in different textures of peach fruit during storage suggested that PpXTH33 was closely related to peach fruit softening during storage.

Key words: Peach, Fruit softening, XTH gene family, Gene expression, Subcellular localization