Cao Yunpeng, Han Yahui, Meng Dandan, Li Guohui, Li Dahui, Abdullah Muhammad, Jin Qing, Lin Yi, Cai Yongping
School of Life Sciences, Anhui Agricultural UniversityHefei, China.
State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural UniversityHefei, China.
Front Genet. 2017 Jun 15;8:78. doi: 10.3389/fgene.2017.00078. eCollection 2017.
WUSCHEL-related homeobox (WOX) family is one of the largest group of transcription factors (TFs) specifically found in plant kingdom. WOX TFs play an important role in plant development processes and evolutionary novelties. Although the roles of in Arabidopsis and rice have been well-studied, however, little are known about the relationships among the main clades in the molecular evolution of these genes in Rosaceae. Here, we carried out a genome-wide analysis and identified 14, 10, 10, and 9 of genes from four Rosaceae species (, , , and , respectively). According to evolutionary analysis, as well as amino acid sequences of their homodomains, these genes were divided into three clades with nine subgroups. Furthermore, due to the conserved structural patterns among these genes, it was proposed that there should exist some highly conserved regions of microsynteny in the four Rosaceae species. Moreover, most of gene pairs were presented with the conserved orientation among syntenic genome regions. In addition, according to substitution models analysis using PMAL software, no significant positive selection was detected, but type I functional divergence was identified among certain amino acids in WOX protein. These results revealed that the relaxed purifying selection might be the main driving force during the evolution of genes in the tested Rosaceae species. Our result will be useful for further precise research on evolution of the genes in family Rosaceae.
WUSCHEL相关同源异型框（WOX）家族是植物界特有的最大转录因子（TFs）群体之一。WOX转录因子在植物发育过程和进化新特性中发挥着重要作用。尽管拟南芥和水稻中WOX的作用已得到充分研究，然而，关于蔷薇科这些基因分子进化中主要分支之间的关系却知之甚少。在此，我们进行了全基因组分析，分别从四种蔷薇科物种（草莓、苹果、桃和梨）中鉴定出14个、10个、10个和9个WOX基因。根据进化分析以及它们同源结构域的氨基酸序列，这些基因被分为三个分支和九个亚组。此外，由于这些WOX基因之间存在保守的结构模式，推测在这四种蔷薇科物种中应该存在一些高度保守的微共线性区域。而且，大多数WOX基因对在共线性基因组区域中呈现出保守的方向。另外，根据使用PMAL软件的替代模型分析，未检测到显著的正选择，但在WOX蛋白的某些氨基酸中鉴定出了I型功能分化。这些结果表明，在受试蔷薇科物种中，宽松的纯化选择可能是WOX基因进化过程中的主要驱动力。我们的结果将有助于对蔷薇科WOX基因的进化进行进一步精确研究。
