植物DXR基因的系统发育和分子进化分析  

Phylogenetic and Molecular Evolution Analyses of DXR Gene in Plants

作　　者：范伟军 杜澄举 黄少伟[2] 司徒少华 欧惠玲 毛积鹏 Fan Weijun;Du Chengju;Huang Shaowei;Situ Shaohua;Ou Huiling;Mao Jipeng(Taishan Hongling Seed Orchart,Taishan,529223;Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm,South China Agricultural University,Guangzhou,510642)

机构地区：[1]台山市红岭种子园,台山529223 [2]华南农业大学,广东省森林植物种质创新与利用重点实验室,广州510642

出　　处：《分子植物育种》2021年第8期2570-2578,共9页Molecular Plant Breeding

基　　金：国家林业局“948”项目(2014-4-72);十三五重点研发子课题项目(2017YFD0600502-3)共同资助。

摘　　要：1-脱氧-D-木酮糖-5-磷酸还原异构酶(DXR)是植物萜类化合物甲基赤藓糖醇-4-磷酸(MEP)生物合成途径的关键酶。为了解其编码基因DXR的系统发育及和分子进化特性。本研究选取了44个代表性物种的DXR基因序列用于系统发育和分子进化分析。结果发现:DXR基因在进化过程中相对保守,受到的平均选择压大小为0.087 1;DXR基因的GC3和G+C平均含量分别为0.365和0.459,偏好以A/T编码;ENC均值为52.48,表明DXR基因的密码子偏好性较低;分枝模型下未检测到受正向选择的进化枝,位点模型下约1%的DXR基因位点受到正向选择作用,分枝-位点模型下裸子植物进化枝中检测到10个受正向选择作用的位点且后验概率大于0.95。本研究为植物DXR基因的进化分析和功能研究提供了一定的理论基础。1-deoxy-D-xylulose-5-phosphate reductoisomerase(DXR) is a key enzyme in the MEP biosynthesis pathway of terpenoids. To understand the phylogenetic and molecular evolution characteristics of the gene DXR.In this study, DXR gene sequences from 44 representative species were selected for phylogenetic and molecular evolution analyses. The results showed that DXR gene was relatively conserved during the evolutionary process,and the average selection pressure was 0.087 1. The average content of GC3 and G +C of DXR genes were 0.365 and 0.459, respectively. Indicating that DXR genes preferred to encode with A/T base;DXR genes showed low codon usage bias with an ENC average value of 52.45;Under branch model, there were no clade detected positive selection. Under the site model, about 1% sites of DXR genes were detected positive selection. Under the branch-site model, 10 positive selection sites were detected in the clade of gymnosperms with a posterior probability greater than 0.95. This study provides a theoretical foundation for the study of evolution analyses and functional reserach of the plants DXR genes.

关 键 词：DXR基因 系统发育 正向选择 分子进化 

分 类 号：Q943.2[生物学—植物学]