巴西橡胶树过氧化氢酶基因HbCAT2的克隆及表达分析  

Molecular Cloning and Expression Analysis of HbCAT2 in Rubber Tree(Hevea brasiliensis)

作　　者：李言[1] 余文才 陈月异[1] 田维敏[1] Li Yan;Yu Wencai;Chen Yueyi;Tian Weimin(State Key Laboratory Incubation Base for Cultivation&Physiology of Tropical Crops,Rubber Research Institute,Key Laboratory of Biology and Ge netic Resources of Rubber Tree,Ministry of Agriculture,Chinese Academy of Tropical Agricultural Sciences,Haikou,571101;Institute of Tropical Agriculture and Forestry,Hainan University,Haikou,570228)

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,海南省热带作物栽培生理学重点实验室,海口571101 [2]海南大学热带农林学院,海口570228

出　　处：《分子植物育种》2019年第21期6993-7002,共10页Molecular Plant Breeding

基　　金：国家天然橡胶产业技术体系分子育种岗位科学家项目(CARS-33-YZ1);中国热带农业科学院橡胶研究所基本科研业务费项目(1630022014002)共同资助

摘　　要：为了探索过氧化氢酶(catalase, CAT)在巴西橡胶树响应低温胁迫应答中的作用。通过RT-PCR技术从橡胶树中分离鉴定了HbCAT2,其c DNA全长1 780 bp,包括1 479 bp开放阅读框,编码492个氨基酸,其分子量为57.18 k D,理论等电点为6.73。该酶的氨基酸序列含有血红素基团必须的5个特定位置氨基酸残基(组氨酸(H) 65,丝氨酸(S) 104,天冬酰胺(N) 138,精氨酸(R) 344和酪氨酸(Y) 348),以及钙调素结合结构域和过氧化物酶体靶信号。荧光定量PCR分析表明,HbCAT2在成熟叶片中的表达显著高于幼嫩叶片。在不同的环境胁迫下表达模式不同,特别在低温(4℃)胁迫下,HbCAT2基因在抗寒性强的橡胶树无性系‘93-114’和抗寒性弱的橡胶树无性系‘热垦501’中都呈现显著上调的表达模式,而且在‘93-114’中的表达量显著高于‘热垦501’。另外,HbCAT2在橡胶树无性系‘热研8-79’寒害较轻原生皮中的表达量较高,在寒害较重再生皮中的表达量较低,而且在抗寒性较强‘PR107’中的表达量显著高于抗寒性较弱‘热研8-79’。推测HbCAT2基因可能参与橡胶树低温胁迫应答。To study the function of catalase(CAT) in the response of Hevea brasiliensis to low temperature stress.By using RT-PCR, a cDNA of HbCAT2 was cloned from the leaf samples of rubber tree clone ’93-114’. The Hb CAT2 was 1 780 base pairs(bp) in length, containing a 1479 bp open reading frame(ORF). The encoded enzyme, HbCAT2, contained 492 amino acid residues with a predicted molecular mass of 57.18 kD and a pI of6.73. The Hb CAT2 had a heme pocket composed by five essential residues: His 65, Ser l04, Asn 138, Arg 344 and Tyr 348, and contained the calmodulin binding domain(CBD) and the peroxisomal targeting signal(PTS1).Real-time quantitative PCR analysis showed that HbCAT2 transcript level was higher in the mature leaves than in the young leaves. Hb CAT2 showed different expression profiles under different environmental stresses, especially cold stress(4℃), it’s expression level was significantly up-regulated in the bark of cold-resistant rubber tree ’93-114’and non-cold-resistant rubber tree ’Reken501’, however, the expression of HbCAT2 was significantly higher in’93-114’ than in ’Reken501’. In addition, HbCAT2 expression level in the virgin bark was significantly higher than that in the renewed bark. There was a significant difference in the level of HbCAT2 expression in the bark of’PR107’ and ’Reyan8-79’, which were both cultivated varieties with differential cold tolerance. The results suggest that HbCAT2 may be crucial in enhancing the bark cold tolerance of rubber tree.

关 键 词：巴西橡胶树(Hevea brasiliensis) 过氧化氢酶 树皮 低温胁迫 

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