巴西橡胶树中2个NADP-苹果酸酶基因的克隆和表达特性分析  

Molecular Cloning and Expression Analysis of NADP-malic Enzyme Gene in Hevea brasiliensis

作　　者：曹冰[1,2] 龙翔宇[2] 肖小虎[2] 唐朝荣[2] 

机构地区：[1]海南大学农学院,海南海口570228 [2]中国热带农业科学院橡胶研究所,海南儋州571737

出　　处：《热带作物学报》2014年第5期872-881,共10页Chinese Journal of Tropical Crops

基　　金：国家"863"课题(No.2013AA102605);国家自然科学基金项目(No.31170630)

摘　　要：从橡胶树中克隆2个NADP-ME(苹果酸酶)基因的全长cDNA,分别命名为HbNADP-ME1和HbNADP-ME2。HbNADP-ME1和HbNADP-ME2 cDNA全长分别为2 428、2 139 bp,分别编码643、593个氨基酸组成的蛋白,二者的氨基酸序列一致性高达87.25%,且分别与蓖麻和杨树的一个NADP-ME序列具有较高的序列一致性。2个HbNADP-ME蛋白都含有典型的植物NADP-ME蛋白的保守结构域,均富含亮氨酸(Leu),同属于非分泌型稳定蛋白。2个HbNADP-ME基因在橡胶树不同组织中的表达存在明显差异,在根中的表达量最高,种子和花中的表达量次之;另外,HbNADP-ME1基因在胶乳中受机械伤害有下调表达趋势,HbNADP-ME2基因在胶乳中受割胶处理也表现出下调表达趋势,而低温胁迫则显著诱导2个基因在叶片和根中的表达。结果说明,HbNADP-ME基因可能参与橡胶树的抗逆应答及代谢调控(包括胶乳代谢调控)。此结果为深入揭示橡胶树中NADP-ME基因的功能奠定了基础。NADP-malic enzyme is a key enzyme in malic acid metabolism pathway and plays important roles in the regulation of cellular pH homeostasis and stress responses in plants. Here, the full-length cDNAs of two NADP-ME genes were first cloned in Hevea brasiliensis （para rubber tree）, and respectively, named HbNADP- ME1 and HbNADP-ME2. The cDNAs of HbNADP-ME1 and HbNADP-ME2 contained 2 428 bp and 2 139 bp nucleotides, and encoded proteins of 643 and 593 amino acids, respectively. HbNADP-ME1 and HbNADP-ME2 shared amino acid identities of 87.25%, and were highly homologous to NADP-ME proteins from Ricinus communis and Populus trichocarpa, respectively. Both HbNADP-ME proteins contained conservative domains typical of plant NADP-MEs, rich in leueine and belonging to the category of non-secreted stable proteins. The HbNADP- ME genes showed distinct expression patterns in different tissues, with the highest expression in roots, and then in seeds and flowers. The expression of HbNADP-ME1 gene was down regulated by wounding, and the expression of HbNADP-ME2 gene was down regulated by tapping, whereas low temperature conspicuously induced the expression of both HbNADP-ME genes in leaves and roots. The results suggested that the HbNADP-ME genes may play roles in the regulation of multiple metabolisms （e.g. latex metabolism） and stress responses in Hevea tree. The results presented will help unravel the physiological roles of the NADP-ME genes in Hevea tree.

关 键 词：巴西橡胶树 NADP-ME 基因克隆 表达分析 胁迫 代谢 

分 类 号：S794.1[农业科学—林木遗传育种]