紫花苜蓿MsCEP基因家族的鉴定及其调控根系生长发育功能的分析  

Identification of Alfalfa(Medicago sativa) MsC EP Genes and Functional Analysis of Its Regulation in Root Growth and Development

作　　者：曾祥翠 杨永念 李如月 蒋学乾 蒋旭[1] 徐嫣然 刘忠宽[3] 龙瑞才[1] 康俊梅[1] 杨青川[1] 李明娜[1] ZENG XiangCui;YANG YongNian;LI RuYue;JIANG XueQian;JIANG Xu;XU YanRan;LIU ZhongKuan;LONG RuiCai;KANG JunMei;YANG QingChuan;LI MingNa(Institute of Animal Sciences,Chinese Academy of Agricultural Sciences,Beijing 100193;College of Forestry and Landscape Architecture,South China Agricultural University,Guangzhou 510642;Institute of Agricultural Resources and Environment Research,Hebei Academy of Agriculture and Forestry Sciences,Shijiazhuang 050051)

机构地区：[1]中国农业科学院北京畜牧兽医研究所,北京100193 [2]华南农业大学林学与风景园林学院,广州510642 [3]河北省农林科学院农业资源环境研究所,石家庄050051

出　　处：《中国农业科学》2024年第24期4839-4853,共15页Scientia Agricultura Sinica

基　　金：河北省耐盐碱作物种业科技创新团队项目(23327501D);中国农业科学院科技创新工程项目(ASTIP-IAS14)。

摘　　要：【目的】碳末端编码肽CEP(C-terminal encoded peptides)为一种能够编码由根系分泌的激素类多肽基因,是调控植物根系生长发育的关键基因。鉴定紫花苜蓿MsCEP基因家族成员,分析其基本特征、不同组织中表达差异,以及对根系生长的作用,为后续解析紫花苜蓿MsCEP基因在根系生长发育中的功能提供分子理论依据。【方法】根据紫花苜蓿新疆大叶基因组信息,以蒺藜苜蓿MtCEP家族蛋白为参考序列,使用TBtools中的本地BLAST及特征结构域筛选鉴定出紫花苜蓿MsCEP基因家族成员。利用生物信息学方法分别分析苜蓿MsCEP的基因基本特征、蛋白基本特征、系统进化关系等。利用转录组数据和实时荧光定量PCR技术分析检测紫花苜蓿MsCEP基因家族成员在不同组织中的表达模式。利用外施试验探究成熟MsCEP肽在根系生长发育中的功能。【结果】在紫花苜蓿新疆大叶基因组中鉴定出35个MsCEP家族成员,分布于18条染色体上,不含有内含子,均具有1个N端信号肽,1个或2个CEP家族保守结构域。MsCEP蛋白氨基酸长度为59—150,分子量为6.7—16.2 kDa,等电点为5.80—10.41,不稳定系数为30.63—89.93,脂肪系数为54.41—134.88,平均疏水指数为-1.110—0.377。亚细胞定位预测显示,MsCEP蛋白主要定位于细胞核、细胞质膜、叶绿体、高尔基体中。系统进化关系分析发现,该家族成员与拟南芥、蒺藜苜蓿的不同成员相互嵌合形成3个分支,其中,最大分支为48个CEP成员。共线性分析发现,紫花苜蓿MsCEP基因与拟南芥和蒺藜苜蓿都存在共线性关系。组织表达分析发现,MsCEP家族成员具有明显的组织特异性,在根中的表达量相对较高,在叶片中的表达量相对较低,甚至不表达,其中有22个在根中的表达量高于其他组织。外施合成的成熟MsCEP2多肽会抑制拟南芥的主根和侧根生长,减少侧根数,降低侧根密度。【结论】在紫花苜蓿新疆大�【Objective】CEP(C-terminal encoded peptides) is a gene that encodes hormone-like peptides secreted by roots and serves as a key regulator of plant root growth and development.To provide a molecular theoretical basis for further elucidating the function of MsCEP genes in root growth and development,members of the Medicago sativa MsCEP gene family,basic characteristics,expression differences in different tissues,and their roles in root growth were identified and analyzed.【Method】Based on the genomic information of the alfalfa cultivar Xinjiang Daye,the MsCEP gene family members of alfalfa were accurately identified using local Blast analysis in TBtools and feature domain by referring to MtCEP family protein of Medicago truncatula sequence.The fundamental genetic and protein characteristics and the phylogenetic relationship of the MsCEP genes were analyzed by bioinformatics methods.The expression patterns of alfalfa MsCEP gene family members in various tissues were assessed using transcriptome data and real-time fluorescence quantitative PCR.The functional roles of mature MsCEP peptides in root growth and development were analyzed by exogenous application experiments.【Result】 A total of 35 MsCEP family members were identified in the genome of alfalfa Xinjiang Daye,and these genes are distributed across 18 chromosomes,lack introns,and all possess an N-terminal signal peptide and one or two conserved domains of the CEP family.The MsCEP members displayed predicted amino acid length ranging from 59 to 150,with molecular weights spanning 6.7 to 16.2 kDa,the isoelectric points varying from 5.80 to 10.41,instability indices ranging from 30.63 to 89.93,aliphatic indices ranging from 54.41 to 134.88,and the grand average of hydropathicity ranging from-1.110 to 0.377.Subcellular localization predictions indicated that the MsCEP protein predominantly localizes to the nucleus,plasma membrane,chloroplast,and Golgi apparatus.Cluster analysis delineated three distinct branches within the family,aligning with counterpart

关 键 词：紫花苜蓿 MsCEP基因家族 CEP2 外施多肽 根系生长发育 

分 类 号：S541.9[农业科学—作物学]