橡胶草E2泛素结合酶基因TkUBC2基因的克隆及其表达分析

为解析橡胶草E2泛素结合酶在胁迫响应和信号转导中的功能,本文从橡胶草品系1151中克隆得到一个E2泛素结合酶基因,命名为TkUBC2,该基因编码区cDNA为459 bp,编码152个氨基酸。序列比对分析发现,不同物种间的UBC2高度同源,TkUBC2与莴苣、向日葵的UBC2相似性高达99%以上。采用荧光定量qRT-PCR技术分析该基因在橡胶草中的表达模式,结果表明,TkUBC2在不同组织中均有表达;而且PEG6000模拟干旱胁迫、甘露醇介导的渗透压胁迫以及植物激素茉莉酸甲酯(MeJA)、脱落酸(ABA)和乙烯利(ET)可诱导TkUBC2下调表达;而NaCl盐胁迫和UV辐射处理则上调TkUBC2表达。结果表明TkUBC2参与橡胶草抗逆反应、激素信号转导以及DNA损伤修复过程,以上结果为进一步解析该基因的功能奠定良好的基础。

Cloning and Expression Analysis of E2 Ubiquitin-conjugating Enzyme Gene TkUBC2 in Taraxacum kok-saghyz Rodin

In order to analyze the function of E2 ubiquitin-conjugating enzyme(UBC)in stress response and signal transduction,an UBC gene was cloned from Taraxacum kok-saghyz Rodin(TKS)line 1151 and named as TkUBC2.The ORF of this gene was 459 bp and encoded 152 aa.Sequence alignment analysis showed that UBC2 shared high level homology among different species,and TkUBC2 had more than 99%similarity with Lactuca sativa LsUBC2 and Helianthus annuus HaUBC2.qRT-PCR was used to analyze the expression pattern of TkUBC2 in TKS.The results indicated that TkUBC2 was ubiquitously expressed in different tissues.Moreover,TkUBC2 expression was down-regulated by treatments of PEG6000 simulated drought stress,mannitol mediated osmotic stress and plant hormone i.e.methyl jasmonate(MeJA),abscisic acid(ABA)and ethylene(ET)respectively,but its expression was up-regulated by the treatments of NaCl salt stress and UV radiation respectively.The results of this study suggested that TkUBC2 was involved in response to various stress conditions,hormone signaling and DNA damage repair process,which lay a good foundation for further revealing the function of TkUBC2 in TKS.