桃生长素受体基因家族生物信息学及其表达模式分析

Bioinformatics and Expression Pattern Analysis of Auxin Receptor Gene Family in Peach

生长素是调控桃果实发育成熟的重要激素之一,在生长素信号通路中,生长素受体TIR1/AFBs处于关键位置,在果实成熟方面发挥着重要的作用。本研究对桃PpTIR1/AFBs基因家族的各个成员进行了生物信息学分析,以硬溶质型‘京玉’和溶质桃‘大久保’为试材,对TIR1/AFBs在桃果实不同发育时期,不同组织部位,不同激素处理后的表达模式进行了RT-qPCR检测。结果表明,桃生长素受体归属于TIR1/AFB1、AFB2、AFB4和AFB6四个亚家族。蛋白结构域分析显示,该家族生长素受体蛋白均含有保守的F-box结构域和LRR结构域。RT-qPCR结果分析发现,4个PpTIR1/AFBs家族基因在桃果实内的表达水平具有组织和时空特异性,在果实发育的S2期,PpTIR1、PpAFB2及PpAFB4在硬溶质果‘京玉’中表达量较高;在S4-1和S4-3时期,PpAFB4基因在‘大久保’中的相对表达量较高。外源生长素处理后的检测结果显示,NAA处理显著下调了PpTIR1和Pp AFB4的表达,上调了PpAFB2和PpAFB6的表达,表明PpTIR1/AFBs转录本对外源生长素有不同的响应,且家族各成员功能具有多样性。

Auxin is one of the important hormones related to peach fruit development and maturation.The auxin receptor TIR1/AFBs is at a key position in the auxin signaling pathway and plays an important role in fruit ripening.In this study,bioinformatics analysis was performed on each member of the peach PpTIR1/AFBs gene family.The expression patterns of TIR1/AFBs were detected by RT-qPCR in different developmental stages,tissue and hormone treatments on peach fruit of non-melting’Jing Yu’and melting’Okubo’.The results showed that the auxin receptor of peach belongs to four subfamilies:TIR1/AFB1,AFB2,AFB4 and AFB6.Analysis of protein domains showed that the auxin receptor proteins contained conserved F-box domain and LRR domain.RT-qPCR analysis showed that the expression levels of four PpTIR1/AFBs family genes in peach fruit had tissue-specific and spatiotemporal specific.In the fruit development of S2,the expression levels of PpTIR1,PpAFB2 and PpAFB4 were higher in’Jing Yu’fruit.However,at S4-1 and S4-3,the relative expression levels of PpAFB4 gene in’Okubo’were higher.After exogenous auxin treatment,NAA treatment significantly reduced the expression of PpTIR1 and PpAFB4,and up-regulated the expression of PpAFB2 and PpAFB6,indicating that the transcripts of PpTIR1/AFBs respond differently to exogenous auxin,and the function of each member is diverse.