谷子F-box家族基因的鉴定、分类及干旱响应

摘要

F-box proteins play critical roles in plant growth and development and respond to abiotic stresses, involving in cell-cycle regulation, cell apoptosis and signal transduction. Foxtail millet has a character with drought-tolerance. We identified 19 up-regulated F-box genes from 525 F-box families under stress in foxtail millet based on the transcriptome sequencing and di-vided them into six subgroups, and the genes in the same subgroup had the same intron-exon structure. These genes were un-evenly distributed on eight foxtail millet chromosomes, and there were six genes on chromosome 2, that gene number was more than that contained on other chromosomes. The analysis of conserved domain of 19 genes showed that all the protein sequences had a conserved F-box motif, and several other domain also existed in C-terminal including FBD, WD40, FBA, ZnF, and Kelch LRR. Putative cis-acting elements showed that the number of MYB and MYC was the most, which ranged from 9 to 78. Tran-scriptome sequencing showed that SiF-box18 was more hypersensitive to the drought stress than other F-box members and re-sponse to drought, salt, ABA, GA, SA, and JA based on the real time PCR. The transient expression in Arabidopsis protoplasts displayed that SiF-box18 protein was localized in nuclear section. This study provided experimental data for further studying the functions of the SiF-box18 gene.%F-box蛋白参与细胞周期调控、细胞凋亡及信号转导等多种生命活动,对维持植物正常生长发育a和介导非生物胁迫响应等过程发挥重要作用。谷子具有显著的耐旱耐瘠薄等特性,本研究根据谷子转录组分析结果,从525个F-box家族成员中鉴定出19个在干旱胁迫下表达量上调的F-box基因,根据序列相似性将其分为6类,同一类基因具有相似的内含子-外显子结构。染色体定位分析发现,这些基因分别分布在谷子的8条染色体上,其中,第2条染色体上含F-box基因最多,有6个。结构域分析结果表明,19个F-box蛋白均含保守的F-box结构域,而C端含FBD、WD40、FBA、ZnF、Kelch和LRR等结构域。启动子元件分析表明,谷子19个F-box基因均含逆境应答元件,其中, MYB和MYC元件的数量最多(9~78个),说明这些基因对干旱应答反应可能主要受MYB、MYC转录因子调控。转录组分析结果表明, SiF-box18基因对干旱胁迫的响应远远高于其他F-box成员,对干旱、高盐、ABA、SA和JA都有响应；亚细胞定位结果显示, SiF-box18蛋白定位在细胞核中。本研究为进一步深入了解SiF-box18基因的功能提供了依据。