茉莉酸信号受体COI蛋白家族的分子进化与基因表达分析

茉莉酸(Jasmonic acid,JA)存在于所有高等植物中,是植物对病原微生物和虫害防御反应的关键激素。在茉莉酸信号转导中,COI1(COR-insensitive 1)作为茉莉酸信号受体蛋白在其中发挥关键作用。本研究采用生物信息学方法,从藻类、苔藓类、蕨类、裸子及单、双子叶植物多谱系对COI蛋白家族进行比较基因组学研究,并取得以下结果:(1)同源基因鉴定结果发现,在所选的7种陆生植物中一共鉴定了55个COIs同源基因,然而,在低等的水生植物包括绿藻类(Chlorophytes)、红藻类(Rhodophytes)、硅藻类(Bacillariophytes)、灰胞藻类(Glaucophytes)及褐藻类(Phaeophytes)等基因组中均未发现其同源基因;(2)系统进化树分析表明,植物COI蛋白家族可以分为4个保守的亚家族,且在陆生植物扩增的同时可能已发生功能分化;(3)基因结构分析显示,植物COI家族基因结构表现多样性,主要体现在内含子的数目和长度上;(4)基因表达数据提示,COI基因家族成员参与植物生长发育的多个时期,且在不同组织器官以及不同的胁迫应答反应中发挥不同的作用。以上结果将为植物COI基因家族的深入研究提供参考。

Molecular evolution and gene expression of Jasmonic acid receptor COI protein family

Jasmonic acid as a plant hormone, which is important on pathogenic microorganisms and insect defense response in high plant. COI1 (COR-insensitive 1) as the receptor of JA signal, plays a key role in the signal transduction. Comparative genomic analysis was performed to investigate the original and evolutionary relationship among COI paralogs in plants. The main results are as follows: (1) 55 COI homologs were identified from 7 representative terrestrial species.Moreover, there were no COI homologs in aquatic algae. Phylogenetic analysis revealed 4 well-conserved subfamilies in plants. Lineage-specific expansion and functional differentiation exists among COI gene family. (3) Exon-intron structure analysis revealed that the gene structures of COI gene family is diversity,which has a variable number and length of introns. (4)Gene data suggest that COI gene family is involved in plant growth and development, and play different roles in different tissues and stress response. We provide valuable information for investigating the COI protein family in plants.