巴西橡胶树HbSAP1基因克隆及表达分析

Cloning and Expression Analysis of HbSAP1 Gene in Hevea brasiliensis

胁迫相关蛋白(Stress associated proteins,SAPs)在植物免疫应答和胁迫反应中发挥着重要作用。采用电子克隆和RT-PCR相结合的方法,从巴西橡胶树中分离胁迫相关蛋白基因Hb SAP1。结果表明:Hb SAP1基因的开放阅读框为537 bp,编码178个氨基酸。Hb SAP1蛋白预测分子量为18.87 ku,等电点为7.98,具有典型的A20和AN1锌指结构域。实时荧光定量PCR分析结果表明,Hb SAP1基因在巴西橡胶树各组织中均有表达,以茎尖中的表达量最高。同健康橡胶树相比,Hb SAP1基因在死皮橡胶树胶乳和树皮中的表达量显著升高。伤害、H2O2、乙烯利及茉莉酸甲酯处理均能使胶乳中Hb SAP1基因的表达上调。低温及PEG诱导的干旱胁迫下,Hb SAP1基因在叶片中的表达显著增强。上述结果表明,Hb SAP1基因可能在橡胶树死皮发生、非生物胁迫应答、乙烯及茉莉酸信号转导中发挥重要调控作用。

SAPs（Stress associated proteins） play an important role in regulating the immune and stress responses in plants. In this study, a SAP gene Hb SAP1 was isolated from Hevea brasiliensis based on in silico cloning and RT-PCR. Hb SAP1 has an open reading frame of 537 bp and encodes 178 amino acids with a calculated molecular weight of 18.87 ku and an isoelectric point of 7.98. Hb SAP1 contains typical A20 and AN1 zinc finger domains. Quantitative real-time PCR analysis showed that Hb SAP1 was expressed in all tested tissues, with the highest expression in stem tip. Compared with the healthy rubber tree, the expression of Hb SAP1 was significantly up-regulated in latex and barks of tapping panel dryness（TPD） rubber tree. The expression of Hb SAP1 in latex was up-regulated by wounding, H2O2, ethephon and Me JA treatments. Moreover, Hb SAP1 expression was significantly increased in the leaves under cold and PEG-induced drought stress conditions. These results suggest that Hb SAP1 may play important roles in regulating TPD occurrence, abiotic stress response, as well as the ethylene and JA signal transduction in rubber tree.