基于叶绿体基因组全序列分析真叶植物叶绿体基因的适应性进化  

Adaptive Evolutionary Analysis of Chloroplast Genes in Euphyllophytes Based on Complete Chloroplast Genome Sequences

作　　者：王博[1,2] 高磊[1] 苏应娟[3] 王艇[1] 

机构地区：[1]中国科学院武汉植物园//中国科学院植物种质创新与特色农业重点实验室,湖北武汉430074 [2]中国科学院研究生院,北京100049 [3]中山大学生命科学学院,广东广州510275

出　　处：《中山大学学报（自然科学版）》2012年第3期108-113,146,共7页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：国家自然科学基金资助项目(30970290;31070594)

摘　　要：真叶植物包括蕨类、裸子植物和被子植物。迄今已积累有较为丰富的真叶植物叶绿体基因组全序列数据。选取了29种真叶植物的叶绿体基因组全序列,采用PAML软件基于位点间可变ω模型,分别分析了蕨类、裸子植物和被子植物叶绿体基因的适应性进化。结果显示:①蕨类、裸子植物和被子植物各有6.5%、7.5%和19.2%的叶绿体基因受正选择作用;被子植物经历正选择的叶绿体基因明显比蕨类和裸子植物为多;②被正选择作用的叶绿体基因主要是遗传系统和光合系统基因,它们的编码产物涉及叶绿体蛋白质合成、基因转录、能量转化与调节及光合作用等过程。推测叶绿体功能基因可能在真叶植物对陆生生态环境的适应过程中起着重要作用。Euphyllophytes comprise ferns,gymnosperms,and angiosperms.Relatively abundant chloroplast genome sequence data has been available for them.In this research,chloroplast gene sequences of 29 euphyllophyte species were extracted from their completely sequenced chloroplast genomes;then an adaptive evolutionary analysis was performed on the chloroplast genes by running PAML under models allowing ω（nonsynonymous/synonymous rate ratio） to vary among sites.The results showed that：①The percentage of chloroplast genes under positive selection in ferns,gymnosperms,and angiosperms were 6.5%、7.5% and 19.2%,respectively.The number of positively selected genes in angiosperms appeared significantly larger than that of ferns and gymnosperms.②Most positively selected genes were genetic system or photosynthesis-related genes.Their coding proteins often functioned in chloroplast protein synthesis,gene transcription,energy transformation and regulation,and photosynthesis.We infer that the chloroplast functional genes may have played key roles during the adaptation of euphyllophytes to terrestrial ecosystems.

关 键 词：真叶植物 叶绿体基因 叶绿体基因组全序列 正选择 

分 类 号：Q349[生物学—遗传学] Q949