巴西橡胶树HbRPB11基因的克隆与表达分析  

Molecular Cloning and Expression Analysis of an HbRPB11 Gene in Rubber Tree(Hevea brasiliensis)

作　　者：晁金泉[1] 杨署光[1] 陈月异[1] 田维敏[1] 

机构地区：[1]中国热带农业科学院橡胶研究所农业部橡胶树生物学与遗传资源利用重点实验室省部共建国家重点实验室培育基地-海南省热带作物栽培生理学重点实验室,儋州571737

出　　处：《分子植物育种》2017年第9期3482-3488,共7页Molecular Plant Breeding

基　　金：现代农业产业技术体系建设专项资金(CARS-34-GW1);中国热带农业科学院橡胶研究所基本科研业务费(1630022014004)共同资助

摘　　要：橡胶树树皮中的次生乳管是天然橡胶合成和贮存的主要场所。生产上施用乙烯利通过延长橡胶树割胶后的排胶持续时间,调节胶乳代谢,从而达到增产的目的。但目前对于转录复合体关键成员RNA聚合酶Ⅱ在胶乳代谢过程中的动态变化尚不清楚。本研究采用RACE和RT-PCR方法,从橡胶树无性系CATAS7-33-97的胶乳中克隆到编码RNA聚合酶Ⅱ关键亚基RPB11的同源基因,命名为HbRPB11。该基因全长659 bp,包含351 bp的开放阅读框,编码一个由116个氨基酸残基组成的蛋白质。该蛋白质分子量为13.53 k D,理论等电点为5.934。实时荧光定量PCR结果表明,HbRPB11在橡胶树的多个组织中均有表达,其中在成熟叶片和胶乳中的表达量最高,并且受割胶和乙烯利处理显著上调。橡胶树不同种质间的表达模式分析显示HbRPB11基因在橡胶合成效率高的种质中的表达量要显著高于橡胶合成效率低的种质,表明该基因的表达量与橡胶合成效率呈正相关性,有可能作为生产上筛选高效合成橡胶种质材料的分子标记。Laticifer is a specific tissue for natural rubber biosynthesis and storage in the bark of rubber tree（Hevea brasiliensis Muell. Arg.）. Application ethrel can significantly improve natural rubber production by regulating latex metabolism and prolonging the duration of latex flow after tapping. RPB11 is one of crucial subunits of eukaryotic RNAP Ⅱ and plays a key role in RNAP Ⅱ assembly. However, there is little known about its function in latex metabolism. In the present, a full-length c DNA, designated Hb RPB11, was isolated from the latex of rubber tree clone CATAS7-33-97 by amplification of c DNA ends（RACE） and RT-PCR methods. Hb RPB11 was 659 bp in length and contained a 351 bp open reading frame encoding a putative protein of 116 amino acids. The predicted molecular mass of Hb RPB11 was 13.53 kilodalton with an isoelectric point（p I） of 5.934. Tissue specificity analysis showed that the amount of Hb RPB11 was abundantly in mature leaf and latex. Its expression level was up-regulated by both tapping and ethrel treatment. Further analysis showed that its expression level in clones with high natural rubber biosynthesis efficiency was higher than that clones with low natural rubber biosynthesis efficiency, suggesting the amount of Hb RPB11 is positively associated with rubber biosynthesis efficiency, which might be used as a molecular marker for selecting rubber tree clones with highly efficient ability for natural rubber biosynthesis.

关 键 词：橡胶树 乳管细胞 胶乳 橡胶合成效率 HbRPB11 

分 类 号：Q943.2[生物学—植物学] S794.1[农业科学—林木遗传育种]