《植物生理学报》 2016, 52(6): 917-925

巴西橡胶树(Hevea brasiliensis) HbMlo7基因克隆与表达分析

何海霞, 张宇^*, 王萌, 杨叶, 郑服丛

海南大学环境与植物保护学院, 海口570228

通信作者：张；E-mail: yuzhang_rain@hainu.edu.cn

摘　要：

Mlo基因是一种植物防卫相关基因, 负调控植物白粉病抗性。为解析巴西橡胶树(Hevea brasiliensis)中Mlo基因的结构与功能, 从橡胶树品种‘热研7-33-97’胶乳中扩增了一个Mlo cDNA序列, 将其命名为HbMlo7。该基因编码499个氨基酸, 分子量为56.85 kDa。蛋白结构分析发现, 该蛋白含有Mlo保守结构域, 有一个核定位信号和7个跨膜结构区域, 无信号肽。通过qRT-PCR发现HbMlo7基因主要在橡胶树树皮中表达, 其表达量在干旱、机械伤害和白粉菌侵染处理下显著上调。脱落酸(ABA)、乙烯利(ETH)、茉莉酸(JA)和过氧化氢(H₂O₂)均能诱导橡胶树叶片中HbMlo7基因显著上调表达。研究认为HbMlo7是植物Mlo家族成员, 参与橡胶树的抗逆反应机制和植物激素信号传导途径。

关键词：巴西橡胶树; 基因克隆; 生物信息学; 表达分析

收稿：2016-03-10   修定：2016-05-16

资助：国家天然橡胶产业技术体系(CARS-34-GW8)、国家自然科学基金(31460197)、2015年海南省研究生创新科研项目(Hys2015-11)和海南省自然科学基金(314059)。

Molecular cloning and characterization of HbMlo7 gene in rubber tree (Hevea brasiliensis)

HE Hai-Xia, ZHANG Yu^*, WANG Meng, YANG Ye, ZHENG Fu-Cong

Environment and Plant Protection College, Hainan University, Haikou 570228, China

Corresponding author: ZHANG Yu; E-mail: yuzhang_rain@hainu.edu.cn

Abstract:

Mildew resistance locuso (Mlo) is a defence-related gene in plant, which negatively regulates plant resistance to powdery mildew. To analyze the structure and function of Mlo gene in Hevea brasiliensis, we cloned a cDNA sequence of Mlo from latex of the rubber tree clone ‘Reyan 7-33-97’. We defined it as HbMlo7. HbMlo7 gene encoded 499 amino acids with a predicted molecular mass of 56.85 kDa. The protein structure analysis revealed that HbMLO7 has one conserved domain of Mlo, one nuclear localization signal (NLS), seven transmembrane domains, and no signal peptide. Gene expression analysis by quantitative and reverse transcription PCR (qRT-PCR) indicated that HbMlo7 expressed mainly in the bark of the rubber tree. The expression level of HbMlo7 was induced by drought, wounding and powdery mildew infection. Abscisic acid (ABA), ethephon (ETH), jasmonic acid (JA) and hydrogen peroxide (H₂O₂) significantly upregulated HbMlo7 gene expression in rubber tree leaves. The results suggest that HbMlo7 is one of the members of Mlo family, and involved in response mechanisms of stress and signal transduction pathway of plant hormones in rubber tree.

Key words: Hevea brasiliensis; gene cloning; bioinformatics; expression analysis