毛竹APX基因系统进化与表达分析

Phylogenetic evolution and expression analysis of APX gene in Phyllostachys edulis

关键词:  毛竹, APX基因家族, 生物信息学, 系统进化, 基因表达

Key words:  Phyllostachys edulis, APX gene family, bioinformatics, phylogenetic evolution, gene expression

摘要:

抗坏血酸过氧化物酶(aseorbate peroxidase, APX)是植物活性氧代谢中重要的抗氧化酶之一,尤其是叶绿体中清除H₂O₂的关键酶,也是维生素C代谢的主要酶类。该文基于生物信息学方法,利用毛竹的基因组及转录组数据鉴定毛竹中的APX基因家族成员,并对其编码的蛋白基本理化性质、基因结构、启动子元件、系统进化及共线性关系、重复串联基因、GO注释及表达模式进行综合分析,共鉴定出21种编码APX的基因。结果表明:(1)PeAPX基因家族成员多为不稳定疏水蛋白,基因结构、基序及结构域相对较为保守,大多数APX基因具有高度保守的内含子模式。(2)系统进化关系显示毛竹APX基因与水稻APX基因有着较高的同源性关系,PeAPX具有较高的进化保守性。(3)Ka/Ks分析表明PeAPX基因都经历了纯化选择压力,此外在每个APX基因的启动子序列中发现有许多与应激反应和植物激素相关的顺式作用元件,结合表达量分析,表明毛竹APX基因在毛竹生长发育中起着正向促进作用。该研究为进一步了解毛竹APX基因家族基本功能及其抗氧化机制提供了一定的参考,为毛竹APX基因功能的深层次鉴定提供了重要依据。

Abstract:

Aseorbate peroxidase(APX)is one of the important antioxidant enzymes in the active oxygen metabolism of plants, especially the key enzyme to remove H₂O₂ from chloroplasts, and also the main enzyme in vitamin C metabolism. In this study, a total of 21 species encoding APX gene were identified based on bioinformatics methods, useing Phyllostachys edulis in the genome and transcriptome data to identify of PeAPX gene family members, through comprehensively analyzing its coding protein, basic physical and chemical properties, gene structure, promoter element, system evolution and the collinearity relationship, repeat the tandem, GO annotation and expression pattern. The results were as follows:(1)Most members of the PeAPX gene family were unstable hydrophobic proteins, and the gene structure, motif and domain were relatively conservative, and most APX genes have a highly conserved intron pattern.(2)Phylogenetic relationship showed that APX gene of P. edulis had high homology with APX gene of Oryza sativa, and PeAPX had a high evolutionary conservatism.(3)Ka/Ks analysis showed that all PeAPX genes experienced purified selection pressure. In addition, many cis-acting elements related to stress response and plant hormones were found in the promoter sequence of each APX gene. Combined with expression analysis, it was indicated that APX gene played a positive role in the growth and development of Phyllostachys edulis. This study provides a reference for further understanding of the basic functions of the APX gene family and its antioxidant mechanism, and provides an important reference for the in-depth identification of the functions of APX genes.