4种模式植物LRRⅧ-2亚家族基因的鉴定和进化历史分析  

Identification and Evolution of LRRⅧ-2 Subfamily Genes in Four Model Plant Species

作　　者：闫晨阳 陈赢男[1,2] Chenyang Yan;Yingnan Chen(Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education,Nanjing Forestry University,Nanjing 210037,China;Co-Innovation Center for the Sustainable Forestry in Southern China,College of Forestry,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]南京林业大学,林木遗传与生物技术省部共建教育部重点实验室,南京210037 [2]南京林业大学林学院,南方现代林业协同创新中心,南京210037

出　　处：《植物学报》2020年第4期442-456,共15页Chinese Bulletin of Botany

基　　金：青年人才托举工程(No.YESS20160121);江苏省高校“青蓝工程”优秀青年骨干教师和江苏省优势学科(PAPD)。

摘　　要：全基因组重复与串联重复是发生基因重复的重要机制,也是基因组和遗传系统多样化的重要动力。LRR-RLK编码富含亮氨酸重复的类受体蛋白激酶,是被子植物进化史上发生大规模扩张而形成的多基因家族。拟南芥(Arabidopsis thaliana)AtLRR-RLK包含15个亚家族,AtLRRⅧ-2是其中发生串联重复比例最高的亚家族。通过分析拟南芥、杨树(Populustrichocarpa)、葡萄(Vitis vinifera)和番木瓜(Carica papaya)4种模式植物中LRRⅧ-2亚家族基因的扩张及差异保留情况,结果显示,LRRⅧ-2在杨树中的扩张程度最高,在拟南芥和葡萄中的扩张程度居中,但在番木瓜中发生丢失。拟南芥、杨树和葡萄LRRⅧ-2亚家族具有旁系同源基因对,但在番木瓜中未发现旁系同源基因。除杨树中的1对旁系同源基因外,4种模式植物中LRRⅧ-2亚家族的旁系和直系同源基因都受到较强的纯化选择作用。对LRRⅧ-2亚家族进化历史的深入分析有助于理解基因重复在植物进化中的作用和意义,可为预测同源基因功能及解析其它基因家族进化历史提供参考。Whole-genome duplication and tandem duplication are two important mechanisms for gene duplication,which play important roles in promoting the genomic and genetic diversity.In Arabidopsis,At LRR-RLK encodes receptor-like kinases rich in leucine repeats,which is a multi-gene family arising from large-scale gene expansion during angiosperm evolution.It is composed of 15 subfamilies,among which,At LRRⅧ-2 is the subfamily with the highest proportion of tandem repeats.In this study,we use the genes in LRRⅧ-2 as an example to analyze the gene expansion and differential retention in four model plants(Arabidopsis thaliana,Populus trichocarpa,Vitis vinifera and Carica papaya).Results showed that paralogous gene pairs were identified in the LRRⅧ-2 subfamily in Arabidopsis,poplar and grape,while no such pair was found in papaya.The LRRⅧ-2 subfamily expanded the most significantly in poplar and moderately expanded in Arabidopsis and grape,but some genes of the LRRⅧ-2 subfamily in papaya have been lost.In addition,the paralogous and orthologous genes in the LRRⅧ-2 subfamily were under strong purifying selection in the four investigated plant species,except for a pair of paralogous genes in poplar.An in-depth phylogenetic analysis of the LRRⅧ-2 subfamily helps to understand the role and significance of gene duplication in plant evolution,and provides useful information for predicting the function of homologous gene among different species.This analytical pipeline is also applicable for deciphering the evolution history of other gene families.

关 键 词：类受体蛋白激酶 富含亮氨酸重复 全基因组重复 串联重复 

分 类 号：Q943.2[生物学—植物学]