不同植物Mlo基因全基因组鉴定及系统进化分析  

Genome-wide Identification and Phylogenetic Analysis of Mlo Gene Family in Different Plants

作　　者：史建磊[1,2] 万红建 熊自立[1] 张海利[1] 马彦如[1] 苏世闻[1] 宰文珊[1] Shi Jianlei;Wan Hongjian;Xiong Zili;Zhang Haili;Ma Yanru;Su Shiwen;Zai Wenshan(Zhenan Key Laboratory of Crop Breeding,Wenzhou Vocational College of Science and Technology,Wenzhou Academy of Agricultural Sciences,Wenzhou,325006;College of Agriculture,Fujian Agriculture and Forestry University,Fuzhou,350002;Institute of Vegetables,Zhejiang Academy of Agricultural Sciences,Hangzhou,310021)

机构地区：[1]温州科技职业学院,温州市农业科学研究院,浙南作物育种重点实验室,温州325006 [2]福建农林大学农学院,福州350002 [3]浙江省农业科学院蔬菜研究所,杭州310021

出　　处：《基因组学与应用生物学》2020年第8期3541-3553,共13页Genomics and Applied Biology

基　　金：温州科技职业学院博士科研启动项目(20183001);浙江省高等学校访问学者项目(FX2018147);浙江省农业(蔬菜)新品种选育重大科技专项子课题(2016C02051-1-2);浙江省教育厅一般科研项目(Y201840413);温州市基础性科研项目(N20180003)共同资助。

摘　　要：Mlo作为一类广谱抗病因子,参与植物多种生物与非生物胁迫反应。为研究不同物种Mlo基因的基本特征及进化关系,选取已测序的29种代表性植物,利用生物信息学方法对其进行鉴定及系统进化分析。结果显示:共有198个植物Mlo基因被鉴定,各基因具有11~14个外显子,编码400~600个氨基酸,翻译碱性疏水性稳定蛋白,部分Mlo含信号肽和钙调素结合区,绝大多数Mlo定位于细胞膜,含5~7个跨膜螺旋结构。基序分析发现,10个保守基序长21~50个氨基酸。染色体定位发现174个Mlo不均衡地散布于不同染色体或scaffold上,且主要位于两端,形成19个(24.1%)基因簇、5对(5.7%)串联重复和61对(36.2%)片段重复。系统聚类可将164个Mlo分为Ⅰ、Ⅱ、Ⅲ三个区组,被子植物Mlo主要聚在ⅠA组,江南卷柏Mlo聚在ⅠA和ⅢB组,小立碗藓Mlo聚在ⅠB和ⅢA组,几乎所有藻类Mlo聚在Ⅱ组。同源性分析发现52.4%的Mlo以同源基因形式存在,包括25对直系同源基因和28对旁系同源基因,其Ka/Ks值为0.01~0.78,说明进化中主要受到纯化选择。研究表明植物Mlo基因家族较保守,具有成簇存在的特点,在进化过程中经重复扩张,形成了大量同源基因,同时也发生了不同程度的丢失,结果为相关基因分离及植物抗病育种应用提供了理论依据。As a broad-spectrum disease resistance factor,Mlo is involved in a variety of biotic and abiotic stress responses in plants.In order to study the basic characteristics and evolutionary relationship of Mlo genes in different species,29 representative plants that had been sequenced were identified and phylogenetically analyzed using bioinformatics methods.The results showed that a total of 198 Mlo genes were identified,the exons ranged from 11 to 14,encoding amino acids ranged from 400 to 600,translating an alkaline,hydrophobic and stable protein.Some Mlo proteins contained a signal peptide and a calmodulin binding domain,the vast majority of Mlo proteins were located in the cell membrane,and the transmembrane domains ranged from 5 to 7.The amino acids of 10 conserved motifs ranged from 21 to 50 in length.Chromosomal localization revealed that 174 Mlo genes were unevenly distributed on different chromosomes or scaffolds,and were mainly located at both ends,forming19(24.1%)gene clusters,5 pairs(5.7%)tandem duplication genes,and 61 pairs(36.2%)segment duplication genes.Systematic clustering divided 164 Mlo proteins into three groups:Ⅰ,ⅡandⅢ.The angiosperm Mlo were mainly clustered in groupⅠA,the Mlo were clustered in groupⅠA andⅢB in Selaginella moellendorffii,the Mlo were clustered in groupⅠB andⅢA in Physcomitrella patens,and almost all algae Mlo were clustered in groupⅡ.Gene homology analysis revealed that 52.4%of Mlo had homologous genes,including 25 pairs of orthologous genes and 28 pairs of paralogous genes with Ka/Ks values ranging from 0.01 to 0.78,indicating that purification selection had occurred in evolution.It indicates that plant Mlo genes are conserved and existed in clusters.During the evolution,a large number of homologous genes have appeared through gene expansion,and at the same time,different degrees of loss have occurred.The results lay a foundation for the isolation and application of related genes in plant disease resistance breeding.

关 键 词：Mlo基因家族 生物信息学 基因重复 系统聚类 同源基因 

分 类 号：Q943.2[生物学—植物学]