粗山羊草CCT家族基因序列分析及激素响应

开花是植物生长发育的重要过程。CCT家族基因在植物中广泛存在, 参与植物花期的调控过程。该文从粗山羊草(Aegilops tauschii)全基因组中分离出26个CCT基因, 它们分布于7对染色体上, 按照排列顺序将其命名为AetCCT1-26。AetCCT蛋白分子量介于14.9 kDa (AetCCT3)-83.2 kDa (AetCCT12)之间, 其中有25个蛋白包含完整的CCT保守结构域。系统发育分析显示, 12对粗山羊草/乌拉尔图小麦(Triticum urartu) CCT蛋白和9对粗山羊草/水稻(Oryza sativa) CCT蛋白为直系同源蛋白。通过公共数据的数字表达分析表明, AetCCT具有组织特异性和组成型2种表达形式, 其中AetCCT3、AetCCT4、AetCCT7及AetCCT9等9个基因在大部分组织中都有表达, 而AetCCT15、AetCCT21和AetCCT25等基因分别在种子、叶和根等少数组织中特异表达。AetCCT家族可以响应不同外源激素, 施用激素24小时和72小时后各成员对激素响应整体表现一致, 但不同成员对于不同激素的响应存在差异, 表明该家族成员在功能和行使方式等方面具有一定的多样性, 可能参与不同生长发育过程。光照条件影响AetCCT的表达, 说明光照和春化作用是影响与调控该家族基因表达的重要因素。研究结果有助于探索小麦(T. aestivum)进化、驯化和演变的规律, 以及认识重要农艺性状的形成与互作网络。

Whole-genome Analysis of CCT Gene Family and Their Responses to Phytohormones in Aegilops tauschii

The control of flowering time is a crucial environmental adaptation in plants; numerous CCT domain genes control flowering in plants. Bioinformatics was used for a genome-wide research of CCT domain genes in Aegilops tauschii. In this study, 26 CCT domain genes were identified in A. tauschii, distributed on seven chromosomes of the A. tauschii genome. The predicted molecular weight of this family was spread over 14.9 to 83.2 kDa, and 25 proteins contain a complete CCT conserved structure domain. Twelve pairs of A. tauschii-Triticum urartu and 9 pairs of A. tauschii-rice CCT proteins were orthologous in the phylogenetic tree. Specific expression and constitutive expression were found in the CCT gene family; nine AetCCT genes were constitutively expressed in all organisms, including AetCCT3, AetCCT4, AetCCT7 and AetCCT9; AetCCT15, AetCCT21 and AetCCT25 were specifically expressed in leaf, seed and roots of A. tauschii, respectively. Moreover, the members responded to phytohormone treatments differently, which suggested a complex function and characteristic in metabolism of this family. Light conditions affect the expression of AetCCT, and this gene family is regulated by photoperiod and vernalization. The results of this paper not only provide useful information for wheat evolution studies, but also provide theory basis for comprehensive understanding of formation and interaction characteristics of important traits.