膜蕨科植物rbcL基因的适应性进化和共进化分析
发布时间：2018-08-28 20:41
【摘要】：膜蕨科植物是薄囊蕨类中种类最多的科,主要分布在潮湿的热带地区,拥有陆生、附生、半附生和攀生等多种生态型。为进一步了解膜蕨科植物辐射式物种分化的分子适应机制,该研究在时间框架下采用位点模型对膜蕨科植物rbc L基因的进化式样进行分析。结果表明:共鉴定出6个氨基酸正选择位点(125I、227L、231A、258F、304S和351L),其中位点304S位于环六上,对维持Rubisco功能有重要作用。此外,还计算了Rubisco大亚基内部氨基酸位点之间的共进化关系,共检测出39组(35个氨基酸)共进化位点,其中位点在α螺旋上的占46%,在β折叠上的占14%。膜蕨科植物rbc L基因这种复杂的进化式样可能与其起源较早有关。鉴于此,基于UCLD分子钟模型对膜蕨科植物的分化时间进行了估计,结果显示膜蕨科植物首次发生分歧的时间在三叠纪早期,瓶蕨属和膜蕨属的分歧时间分别发生在侏罗纪早期和白垩纪晚期,并且得出陆生生态型是其它生态型进化的基础,推测最近几次最热事件可能对物种分化的形成产生一定的作用。该研究结果对认识膜蕨科植物如何应对被子植物兴起所导致的陆地生态系统改变具重要意义。
[Abstract]:Pteridaceae is the family of the most species of ferns, mainly distributed in humid tropical areas, with terrestrial, epiphytic, semi-epiphytic and climbing ecotypes. In order to further understand the molecular adaptation mechanism of radiative species differentiation in the family Pteridaceae, the evolutionary pattern of rbc L gene was analyzed by locus model under the time frame. The results showed that six positive amino acid selection sites (125Ion 227L, 231A, 258FN 304S and 351L) were identified, among them, 304S was located on ring VI, which played an important role in maintaining the function of Rubisco. In addition, the coevolutionary relationships among amino acid sites in the large subunit of Rubisco were calculated and 39 groups (35 amino acids) were detected, of which 46 were located in 伪 helix and 14 in 尾 folding. The complex evolutionary pattern of rbc L gene may be related to its early origin. Based on the UCLD molecular clock model, the differentiation time of Pteridaceae was estimated. The results showed that the first time of divergence occurred in the early Triassic. The diverging time of Dryopteris and Dryopteris occurred in the early Jurassic and late Cretaceous respectively, and the terrestrial ecotype was the basis of the evolution of other ecotypes. It is speculated that the most recent heat events may play a role in the formation of species differentiation. The results of this study are important for understanding how to deal with the terrestrial ecosystem changes caused by the rise of angiosperms.
【作者单位】： 黔南民族师范学院生物科学与农学院;
【基金】：贵州省科学技术基金(黔科合J字[2015]2137号) 贵州省自然科学基金重点项目(黔教合KY字[2015]380号)~~
【分类号】：Q943.2
本文编号：2210557
[Abstract]:Pteridaceae is the family of the most species of ferns, mainly distributed in humid tropical areas, with terrestrial, epiphytic, semi-epiphytic and climbing ecotypes. In order to further understand the molecular adaptation mechanism of radiative species differentiation in the family Pteridaceae, the evolutionary pattern of rbc L gene was analyzed by locus model under the time frame. The results showed that six positive amino acid selection sites (125Ion 227L, 231A, 258FN 304S and 351L) were identified, among them, 304S was located on ring VI, which played an important role in maintaining the function of Rubisco. In addition, the coevolutionary relationships among amino acid sites in the large subunit of Rubisco were calculated and 39 groups (35 amino acids) were detected, of which 46 were located in 伪 helix and 14 in 尾 folding. The complex evolutionary pattern of rbc L gene may be related to its early origin. Based on the UCLD molecular clock model, the differentiation time of Pteridaceae was estimated. The results showed that the first time of divergence occurred in the early Triassic. The diverging time of Dryopteris and Dryopteris occurred in the early Jurassic and late Cretaceous respectively, and the terrestrial ecotype was the basis of the evolution of other ecotypes. It is speculated that the most recent heat events may play a role in the formation of species differentiation. The results of this study are important for understanding how to deal with the terrestrial ecosystem changes caused by the rise of angiosperms.
【作者单位】： 黔南民族师范学院生物科学与农学院;
【基金】：贵州省科学技术基金(黔科合J字[2015]2137号) 贵州省自然科学基金重点项目(黔教合KY字[2015]380号)~~
【分类号】：Q943.2
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1 张巧艳;苏立娟;刘晓瑞;朱玉琼;张宪春;刘家熙;;膜蕨科系统学研究进展[J];生物技术通报;2006年S1期
，本文编号：2210557
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