拟南芥COMT基因家族的全基因组分析

Genome-wide Analysis of COMT Gene Family in Arabidopsis thaliana

COMT是木质素生物合成途径的关键酶,对植物的抗逆性有着重要意义。为了进一步研究COMT基因的功能,在植物基因组网站Phytozome下载拟南芥等不同植物来源的COMT基因成员,利用HMMER、Pfam与SMART等工具进一步筛选得到17个成员。系统进化树显示COMT基因家族的基本特征在单双子叶植物分离之前就已形成。对17条拟南芥COMT蛋白的理化性质、二级结构、保守基序与染色体定位进行分析。结果表明,拟南芥COMT基因家族成员的二级结构主要:由α-螺旋和无规则卷曲组成;甘氨酸和缬氨酸为含量较高的氨基酸残基;拟南芥COMT基因家族中存在10种不同的保守基序,其中motif 3在所有COMT基因中均有出现;COMT基因在染色体上也呈现不均等分布。盐胁迫处理和比较转录组学分析发现,AT1G21100、AT1G77520与AT1G77530的m RNA表达水平发生显著变化,推测这3条基因可能参与拟南芥对盐胁迫的响应过程,其高表达可能提高拟南芥的耐旱能力,这一结果可为提高植物抗逆性提供理论依据。

COMT(Caffcie acid O-methyltransferase)is a key enzyme in the biosynthetic pathway of lignin,which is greatly significance to the stress resistance of plants.In order to further study the function of COMT genes,in this research,the members of COMT genes from Arabidopsis thaliana and other plants downloaded from the plant genome website Phytozome were firstly detected by the HMMER software,and used HMMER,Pfam and SMART tools to further screen 17 members.According to the phylogenetic tree,it can be seen that the basic characteristics of the COMT gene family were formed before the separation of mono-dicotyledonous plants.The physicochemical properties,secondary structure,conserved motifs and chromosomal location of 17 COMT proteins from Arabidopsis thaliana were analyzed.The results showed that the secondary structure of Arabidopsis COMT members was mainly composed ofα-helix and random coils;glycine and valine were high content amino acid residues;10 motifs were existed in Arabidopsis COMT members,in which motif 3 appeared in all COMT members;COMT genes also showed unequal distribution on various chromosomes.Comparative transcriptome indicated that the m RNA levels of AT1G21100,AT1G77520 and AT1G77530 changed significantly after salt stress treatment.It was speculated that these three members might be involved in the response of Arabidopsis to salt stress,and their high expression might improve the salt tolerance of Arabidopsis.This result would provide a theoretical basis for improving plant resistance.