作　　者： ; ;

机构地区： 河南师范大学生命科学学院

出　　处： 《北方园艺》 2012年第14期123-126,共4页

摘　　要： 光敏色素是一类红光/远红光受体,在植物从萌发到成熟的整个生长发育过程中都起重要的调节作用。光敏色素N端的光感受区是发色团结合的部位,高度保守。该区域的保守性是确保光敏色素光逆转和光信号转导等功能正常运行的先决条件之一。裸子植物的PHYP基因对应于被子植物的PHYB基因,都属于B类光敏色素基因。为了研究这2个基因的光感受区是否经历选择压力以及是否经历同样的选择压力,基于分支模型,位点模型以及分支-位点模型对裸子植物中8条,被子植物8条共16条序列进行适应性进化分析。结果表明:在该区域构建的系统发育树中,强烈的正选择压力趋向于发生在裸子植物的近期分化的属内种间的谱系中,而在相对距离较远的古老谱系中缺少这种压力,然而,通过目前的模型并未检测到具体的适应性进化的位点;被子植物的PHYB基因中检测出6个发生适应性进化的位点。 Phytochromes, which are the best-characterized plant photosensors,receive and transmit signals generated by red and far-red light. They can regulate a wide range of developmental and physiological responses to changes in light intensity and spectral quality during plant development. The N-terminal of phytochrome is photosensory module, which is covalently attached to the bilin chromophore. The conservation of the photosensory module is one of the functional prerequisites for phytochrome photoconversion and signal transduction. PHYP is the gymnosperm orthologue of PHYB. Both of the genes belong to B-type gene. In order to identify lineages and sites under positive selection, the molecular evolution of 8 gymnosperm and 8 gymnosperm photosensory module sequences were assayed under the branch model, the site model and the branch-site model established by Yang et al in this study. The results showed that strong positive selective pressure tends to occur in the recent PHYP lineages of eogeneric species but absent in old lineages consisting of distantly related species;6 positively selected sites have been identified in PHYB photosensory module of angiosperms.

关 键 词： 裸子植物 被子植物 适应性进化

领　　域： [生物学]