巴西橡胶树HbUBC5基因克隆、生物信息学及表达分析

Cloning and Bioinformatic and Expression Analysis of HbUBC5 from Hevea brasiliensis

为研究巴西橡胶树泛素结合酶(UBC)基因功能,采用PCR技术从巴西橡胶树中克隆了一个UBC基因,用半定量RTPCR分析基因表达模式,同时对基因编码蛋白进行生物信息学分析。结果表明,基因长681 bp,最长开放阅读框555 bp,预测编码蛋白包含184个氨基酸;序列比对分析发现,该基因编码的蛋白具有一段保守的UBC结构域,与拟南芥E2成员UBC5(At1g63800)具有较高的相似性,故将该基因命名为HbUBC5。半定量RT-PCR分析结果表明,HbUBC5在巴西橡胶树胶乳中表达最高,在树皮中表达最低。HbUBC5在叶片不同发育时期表达模式存在变化,在古铜期最低,在稳定期最高。与健康橡胶树相比,死皮树胶乳中HbUBC5表达量明显下降。HbUBC5表达还受乙烯和茉莉酸调控。以上结果表明,HbUBC5可能在巴西橡胶树死皮、产排胶、乙烯和茉莉酸反应中发挥作用。

In order to study the function of ubiquitin conjugating enzyme （UBC） gene in rubber tree, an UBC gene was cloned with PCR method and the gene expression patterns with semi-quantitative RT-PCR were studied. In addition, the characterization of the protein encoded by the UBC gene was analyzed with bioinformatics method. The UBC gene was 681 bp with a 555 bp open reading frame, encoding a deduced 184 amino acids. The deduced protein contained a predicted UBC domain and showed high identity to an E2 member Atlg63800 （UBC5）, therefore the UBC gene identified in this study was named as HbUBCS. Semi-quantitative RT-PCR analysis indicated that the highest and lowest expression of HbUBC5 was separately in latex and barks. The HbUBC5 expression varied depending on leaves development, with the highest expression in mature leaves and the lowest in red leaves. Compared with tapping panel dryness （TPD） rubber tree, Hb UBC5 was obviously unregulated in healthy rubber tree. The expression of Hb UBC5 was also regulated by ethylene and jasmonic acid treatments. The results suggested that Hb UBC5 might play key roles in TPD, latex biosynthesis and flow, ethylene, and jasmonic acid responses in Hevea brasiliensis.