小立碗藓泛素连接酶U-box家族的鉴定及表达分析

Genome-wide identification and expression analysis of E3 ubiquitin-protein ligase U-box family in Physcomitrium patens

关键词:  小立碗藓, U-box家族, 基因表达, 功能分析, 全基因组鉴定

Key words:  Physcomitrium patens, U-box family, gene expression, functional analysis, genome-wide identification

摘要:

U-box家族编码E3泛素连接酶能够特异性识别底物,从而调控蛋白的修饰和降解过程。为鉴定小立碗藓U-box家族成员,分析其生物学特征及基因表达规律,该研究基于小立碗藓的全基因组测序数据,通过生物信息学技术对泛素连接酶U-box家族成员的理化性质、进化关系、顺式作用元件、组织表达模式、胁迫响应等进行了分析。结果表明:(1)在小立碗藓全基因组中共鉴定得到31个U-box家族成员,并且不均匀地分布于14条染色体上; 其分子量大小在37.75～117.49 kDa之间,等电点介于5.32～8.55之间。(2)进化树显示,小立碗藓的U-box家族成员分布在I-IX亚家族中,其中亚家族VII含有小立碗藓成员最多,共11个(约占36.67%),说明小立碗藓在历史进化过程中具有高度保守性且功能多样化。(3)经启动子分析发现,小立碗藓U-box家族成员具有结合GA和ABA等多个激素的元件。(4)组织表达分析发现小立碗藓U-box家族成员主要在绿丝体、轴丝体和孢子体S3时期大量表达。(5)通过ABA、甘露醇和饱和LiCl处理后发现,配子体的拟茎均发生黄化且PpPUB21的表达量均被显著诱导。推测小立碗藓U-box家族成员在生长发育和响应逆境胁迫中发挥着重要作用,这为后续深入研究小立碗藓U-box家族成员的基因功能研究奠定了理论基础,也为其相关研究提供了参考。

Abstract:

The U-box family encodes E3 ubiquitin ligase, which can specifically recognize the substrate and thus regulate the process of protein modification and degradation. In order to identificate the members of the Physcomitrium patens U-box family and to analyze their gene expression regularities, their physicochemical characteristics, evolutionary relationship, cis-acting element, tissue expression patterns and stress response were analyzed based on the whole sequencing data of P. patens through bioinformatics technology. The results were as follows:(1)A total of 31 U-box family members were identified in the whole genome of P. patens and were unevenly distributed on 14 chromosomes; their molecular weight sizes ranged from 37.75-117.49 kDa, and their isoelectric points ranged from 5.32-8.55.(2)The evolutionary tree showed that the U-box family members of P. patens were distributed in subfamilies I-IX, among which subfamily Ⅶ contained the largest number of members, with a total of 11 members accounting for about 36.67%. This indicated that P. patens was highly conserved and functionally diversified in the historical evolutionary process.(3)Promoter analysis yielded that P. patens U-box family members had elements that binded several hormones including GA and ABA.(4)Tissue expression analysis yielded that P. patens U-box family members was abundantly expressed mainly in the chloroplast, axoplast, and sporophyte S3 periods.(5)After simulated drought treatment with ABA, mannitol and saturated LiCl, it was found that the proposed stems of gametophytes were yellowed and the expression of PpPUB21 was significantly induced. It is hypothesized that the P. patens U-box family members plays an important role in growth and development and in response to adversity stress, and these findings provide a reference for further research on the U-box gene of P. patens.