粗山羊草CCT基因家族进化及节律表达分析

Evolution and Rhythm Expression Research on CCT Family Genes of Aegilops tauschii Coss.

CCT家族基因广泛参与植物花期的调控过程,粗山羊草(Aegilops tauschii Coss.)作为小麦D基因组供体,给小麦带来新的花期及适应性相关基因。研究粗山羊草CCT家族基因不仅可为小麦进化、驯化和演变规律提供参考,还有助于认识粗山羊草作为杂草的生态适应性。粗山羊草基因组中26个CCT基因进化分析后发现Group A、Group C、GroupH和Group G中的13个Aet CCT成员出现了快速进化;Group A中有42.1%的位点存在正选择效应,表明快速进化提高了粗山羊草的适应性。基因结构分析表明CCT结构域在Aet CCT家族中保守性很高,但不同基因内含子和外显子的排布差异较大,特异Motif可能是不同亚家族基因间功能差异的重要原因。Aet CCT4、Aet CCT7、Aet CCT8、Aet CCT11、Aet CCT12、Aet CCT16、Aet CCT17、Aet CCT19、Aet CCT21和Aet CCT22的表达具有明显的"生物钟效应",呈现出24 h的节律性表达,且基本都处于快速进化的Group A、Group C、GroupH和Group I。研究结果表明,这些成员可能参与花期调控等生长发育过程,在粗山羊草的适应性形成过程中发挥了作用。

CCT gene family widely participates in the regulation process of flowering of plants. As D genome do- nor of hexaploid wheat,Aegilops tauschii Coss. provides new flowering genes related to adaptability to wheat,which make it adapt to different geographical and ecological environment. Research on CCT gene family of Ae. tauschii Coss. may provide a reference for exploring the wheat＇s evolution, domestication and also help to understand the ec- ological adaptability of Ae. tauschii Coss. The AetCCT were divided into ten subgroups based on phylogenetic analysis in this research. Phylogenetic analysis showed that 13 AetCCT members in Group A ,Group C ,Group H and Group G achieved rapid evolution. After normal selection effect of some branches, rapid evolution improved the adaptability of Ae. tauschii Coss. The conserved motifs analysis suggestted that AetCCT genes in the same group might have similar function, the specific motif of different members among families and within family was likely to be the important rea- son for the different functional differences among different subfamily genes. The expression of AetCCT4,AetCCTT, AetCCT8 , AetCCT11,AetCCT12 , AetCCT16 , AetCCT17 , AetCCT19 , AetCCT21 and AetCCT22 had obvious biological clock effect,with the 24 h rhythm expression and most of them was divided in Group A, Group C, Group H and Group I which achieved rapid evolution. So it was speculated that these members were involved in regulating the growth and development events as flowering.