《植物生理学报》 2013, 49(1): 81-88

烟草二脂酰甘油酰基转移酶基因(NtDGAT2)的克隆与功能分析

阳天泉^1,2, 徐荣华¹, 刘爱忠^1,*

1中国科学院西双版纳热带植物园, 昆明650223; 2中国科学院大学, 北京100049

通信作者：刘爱忠；E-mail: liuaizhong@xtbg.ac.cn；Tel: 0871-65140420

摘　要：

二脂酰甘油酰基转移酶(diacylglycerol acyltransferase, DGAT2)是植物储存油脂生物合成过程中的关键酶, 对种子储存油脂累积具有重要的生理作用。本文采用电子克隆与实验相结合的方法, 从烟草种子cDNA中克隆到DGAT2基因的开放阅读框序列, 命名为NtDGAT2 (GenBank登录号JX843807), 其序列长999 bp, 编码332个氨基酸。多序列比对和进化分析表明该基因编码蛋白与其他植物DGAT2具有较高相似性和典型的DGAT2结构域。利用Real-time PCR定量表达分析显示Nt-DGAT2在烟草种子、花、茎、叶和根里面都有表达, 且在发育中的种子和花的发育过程大量表达。酵母互补实验证实该基因编码蛋白具有DGAT酶活性。

关键词：烟草; 二脂酰甘油酰基转移酶; 酵母; 油脂

收稿：2012-10-17   修定：2012-12-24

资助：国家自然科学基金(30871548)和中国科学院知识创新工程重要方向项目(KSCX2-EW-Z-15)。

Cloning and Characterization of Diacylglycerol Acyltransferase Gene (NtD-GAT2) from Tobacco (Nicotiana tabacum L.)

YANG Tian-Quan^1,2, XU Rong-Hua¹, LIU Ai-Zhong^1,*

¹Xishuangbanna Tropic Botanical Garden, Chinese Academy of Sciences, Kunming 650223, China; ²University of Chinese Academy of Sciences, Beijing 100049, China

Corresponding author: LIU Ai-Zhong; E-mail: liuaizhong@xtbg.ac.cn; Tel: 0871-65140420

Abstract:

Diacylglycerol acyltransferase (DGAT2), a key enzyme for lipid biosynthesis, plays a critical role in oil accumulation in oilseeds. In this study, using the silico cloning technique combined with RT-PCR method, a novel DGAT2 gene with the length of 999 bp encoding 332 amino acids was isolated from seed cDNAs of to-bacco (Nicotiana tabacum), named NtDGAT2 (GenBank No JX843807). The sequence analyses showed that the amino acid sequence of NtDGAT2 with the typical functional motifs of DGAT2 was high similarity to those identified from other species. Based on Real-time quantitative PCR expression analysis, NtDGAT2 was ex-pressed in all tissues such as root, stem, leaf, flower and developing seed; in particular, NtDGAT2 was highly expressed in flowers and developing seeds. Further, the function of NtDGAT2 was confirmed by heterologous transformation and the functional complementary experiments in yeast.

Key words: tabacoo; diacylglycerol acyltransferase; yeast; lipid