《植物生理学报》 2015, 51(4): 429-435

巴西橡胶树HbMKK6基因的克隆及表达分析

吴绍华¹, 陈月异¹, 王建霄^1,2, 田维敏^1,*

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, 海南儋州571737; ²海南大学农学院, 海口570228

通信作者：田维敏；E-mail: wmtian@163.com；Tel: 0898-23300309

摘　要：

促分裂原活化蛋白激酶的激酶(MAPKKs/MKKs)在植物应对逆境胁迫中发挥重要作用。本研究采用RACE和RT-PCR方法, 从巴西橡胶树无性系‘热研7-33-97’的胶乳中克隆了一个MAPKK基因家族成员, 命名为HbMKK6。该基因的全长cDNA包含65 bp的5'非编码区, 316 bp的3'非编码区和1 065 bp的开放阅读框, 编码一个由354个氨基酸残基组成的蛋白质。该蛋白质分子量为39.91 kDa, 理论等电点为5.96, 含有保守的SMGQRDT (S/TxxxxxS/T)基序。实时荧光定量PCR结果表明, HbMKK6在橡胶树的根、皮、胶乳及叶片中均有表达, 其中在叶片中的表达量最高。HbMKK6基因在橡胶树抗寒无性系‘93-114’叶片中的表达丰度显著高于不抗寒无性系‘热垦501’, 而且在4 ℃低温下显著上调。高丰度表达HbMKK6可能与增强橡胶树的抗寒性有关。

关键词：巴西橡胶树; 促分裂原活化蛋白激酶的激酶; 抗寒; HbMKK6; 基因表达

收稿：2014-11-10   修定：2015-03-23

资助：中国热带农业科学院橡胶研究所基本科研业务费专项资金(1630022014002)、国家自然科学基金项目(31300504)。

Cloning and Expression Analysis of a HbMKK6 Gene in Rubber Tree (Hevea brasiliensis)

WU Shao-Hua¹, CHEN Yue-Yi¹, WANG Jian-Xiao^1,2, TIAN Wei-Min^1,*

¹Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Key Laboratory of Biology and Genetic Resources of Rubber Tree, Ministry of Agriculture, State Key Laboratory Incubation Base for Cultivation & Physiology of Tropical Crops, Danzhou, Hainan 571737, China; ²College of Agronomy, Hainan University, Haikou 570228, China

Corresponding author: TIAN Wei-Min; E-mail: wmtian@163.com; Tel: 0898-23300309

Abstract:

Mitogen-activated protein kinase kinases (MAPKKs/MKKs) play an important role in tolerance of plants to abiotic and biotic stresses. In the present study, a full length cDNA sequence of HbMKK6 was obtained from latex of rubber tree (Hevea brasiliensis) clone ‘Reyan 7-33-97’ by rapid-amplification of cDNA ends (RACE) and RT-PCR. The HbMKK6 contained 65 bp 5' untranslation region (UTR), 316 bp 3' UTR and a 1 065 bp open reading frame (ORF). The HbMKK6 contained 354 amino acid residues with a predicted molecular mass of 39.91 kDa and theoretical isoelectric points (pI) of 5.96. It has the consensus sequence SMGQRDT (S/TxxxxxS/T). Real-time RT-PCR analysis showed that HbMKK6 was expressed in root, bark, latex and especially in leaves. The transcripts of HbMKK6 were more abundance in cold-resistant rubber tree clone ‘93-114’ than that in cold-sensitive rubber tree clone ‘Reken 501’. Moreover, the expression of HbMKK6 in the leaves of rubber tree clone ‘93-114’ was significantly up-regulated while it remained hardly changed in the leaves of rubber tree clone ‘Reken 501’ under 4 ℃ treatment. The differential expression of HbMKK6 between the two clones may be associated with their different tolerance to cold stress.

Key words: Hevea brasiliensis; mitogen-activated protein kinase kinase; cold-resistant; HbMKK6; gene expression