蓖麻生长素外输载体PIN蛋白家族的生物信息学分析

Bioinformatics Analysis of the Auxin Efflux Carrier PIN Proteins of Ricinus communis L.

PIN蛋白家族是植物重要的生长素外输载体,通过介导细胞间的生长素极性运输来调控生长素在植物组织间的差异分布,从而调控植物的生长发育。目的:分离鉴定出蓖麻中PIN蛋白家族成员,为蓖麻生长素极性运输机制的研究奠定基础。方法:利用生物信息学分析软件,以拟南芥PIN基因家族序列为模板,在蓖麻基因组数据库中进行PIN基因鉴定,并对鉴定到的候选基因进行序列分析、所编码蛋白的结构域分析、信号肽预测、磷酸化位点分析以及系统进化分析。结果:蓖麻中共鉴定到7条编码PIN蛋白的同源序列,平均长度为537个氨基酸残基,平均分子量为58.64 ku,均属于脂溶性较好的碱性蛋白,结构稳定,具有9至10个跨膜结构域。系统进化分析结果表明,蓖麻PIN基因与同属于大戟科的木薯、橡胶树和麻风树的PIN基因进化关系较为密切。利用蓖麻基因表达数据库对鉴定到的RcPIN基因的表达模式进行了分析,并利用RT-PCR进行了验证,结果表明,RcPIN1-1和RcPIN1-2在根、叶、雌花和胚中表达水平较高,RcPIN2主要在根中表达,RcPIN3、5、6和8在所有检测的组织均有表达。

PIN family proteins are important auxin efflux carriers in plants,which regulate the differential distribution of auxin between plant tissues by mediating the polar auxin transport between cells,thus regulating the growth and development of plants.Objective:To isolate and identify PIN protein family members in castor bean and lay a foundation for the study of polar auxin transport mechanism in castor bean(Ricinus communis L.).Methods:Using bioinformatics analysis software,Arabidopsis thaliana PIN gene family sequences were used to identify the RcPIN genes in castor bean genome database.Sequence analysis,domain analysis,signal peptide prediction,phosphorylation site analysis and phylogenetic analysis of the identified candidate genes were carried out.Results:Seven PIN protein homologous sequences were identified in castor bean,with an average length of 537 amino acid residues and an average molecular weight of 58.64kD.All of them were basic proteins with good fat-solubility,stable structure and with 9 to 10 transmembrane domains.Phylogenetic analysis demonstrated that PIN genes in castor bean is closely related to the ones in Manihot esculenta,Jatropha curcas and Hevea brasiliensis.Expression patterns of the RcPIN genes were analyzed using publicly available transcriptome database and by RT-PCR.The results showed that RcPIN1-1 and RcPIN1-2 genes were strongly expressed in root,leaf,female flower and embryo;RcPIN2 gene was mainly expressed in root;RcPIN3,5,6 and 8 genes were expressed in all the tissues examined.