花生MYB转录因子的鉴定与生物信息学分析

Genome⁃wide identification and bioinformatics analysis of MYB transcription factor family in peanut(Arachis hypogaea)

MYB转录因子是植物中重要的基因家族之一,参与多种生物学功能的调控。目前对花生(Arachis hypogaea)MYB转录因子家族的功能仍知之甚少,对花生中MYB转录因子的鉴定及生物信息学分析具有重要的意义。本研究在栽培花生中共鉴定出MYB转录因子443个,包括219个1R-MYB、209个2R-MYB、12个3R-MYB以及3个4R-MYB,它们不均匀地分布在20条染色体上,大多集中于染色体末端;MYB结构域分析表明,R2结构包含3个极度保守的色氨酸残基,R1第三个保守色氨酸、R3结构域第一个保守色氨酸分别被其它疏水氨基酸替代;系统发育树显示,大多数聚类在相近分支中的MYB转录因子在对应染色体上的分布位置相近。鉴定到的AhMYB部分同源基因对共有170对,其中有72对在至少一个组织中表现出表达偏向性;功能富集分析显示,偏向性基因对、非偏向性基因对、无配对基因对在功能上有一定的差异。栽培花生基因组中的AhMYB基因在转录水平上表达模式各异,但其蛋白具有一定的进化保守性和结构多样性,显示出在花生演化过程中,MYB家族成员存在大量的功能异化。本研究为后续探究AhMYB基因功能奠定了基础。

The MYB family proteins are widely distributed in plants,with important roles in regulating various biological processes.However,the functions of MYB proteins in peanut(Arachis hypogaea,AABB,2 n=40)remain elusive.Therefore,the identification of the MYB gene family from the complete peanut genome sequence and the further bioinformatic analyses of these genes are biologically significant.In the allotetraploid cultivated peanut,443 MYB genes were identified.These genes were grouped into four subfamilies:2191 R-MYB,2092 R-MYB,123 R-MYB,and three 4 R-MYB,and they were unevenly distributed across 20 chromosomes.MYB domain analysis showed that R2 s contained three conserved tryptophan residues,while the third conserved tryptophan residues of R1 s and the first conserved tryptophan residues of R3 s were replaced by other hydrophobic residues.Phylogenetic analysis revealed that most of the members could clustered according to the number and the distribution of their MYB domains.170 AhMYB homoeologous gene pairs were identified and 72 of them showed different expression patterns in at least one tissue or development stage.Gene ontology enrichment analysis showed that the functions of biased-expressed AhMYB,unbiased-expressed AhMYB,and unpaired AhMYB genes were diverse.Although the identified AhMYB transcription factor genes in cultivated peanut showed different expression patterns,the AhMYB proteins displayed structural diversity and evolutionary conservation,suggesting functional divergence among AhMYB genes.This study laid a foundation for functional research of AhMYB genes.