柠条锦鸡儿CkGR基因克隆及功能分析

Cloning and Expression Analysis of CkGR Gene in Caragana korshinskii Kom.

通过RACE技术从柠条锦鸡儿中克隆得到一个新的GR基因,全长2 122 bp,包括5'非翻译区(5'-UTR)57 bp,3'非翻译区(3'-UTR)415 bp,开放阅读框(ORF)1 650 bp,编码550个氨基酸,推测的蛋白质分子量为59.2k Da,理论等电点为8.2,命名为Ck GR。Ck GR与鹰嘴豆Ca GR的同源性较高,为90.1%。利用染色体步移法克隆得到Ck GR起始密码子ATG上游648 bp的启动子序列,Plant CARE软件分析表明,该序列具有启动子的基本元件CAAT-box和TATA-box以及多种与逆境胁迫相关的顺式调控元件。实时荧光定量PCR分析表明,Ck GR在柠条锦鸡儿的根、茎和叶中均有表达,没有组织特异性;Ck GR的表达受低温、高盐和干旱胁迫的诱导,表明Ck GR在柠条锦鸡儿适应低温、高盐和干旱胁迫的过程中发挥作用。

A novel GR genewas isolated from Caragana korshinskii Kom. by RACE. The full-length cDNA of GR was 2 122 bp, containing a 5＇-UTR of 57 bp, a 3＇-UTR of 415 bp, and a 1 650 bp opening reading frame （ORF）. The deduced protein was 550 amino acids with molecular weight 59.2 kDa and isoelectric point 8.2, named CkGR. This CkGR showed high identities with the Cicer arietinum CaGR （90.6%）. The promoter of CkGR gene was isolated by chromosomal walking and 648 bp sequence was obtained by sequencing. Plant CARE analysis of this sequence showed that the peomoter contained some typical elements CAAT-box and TATA-boxand kinds of Cis-acting elements involved in defense and stress responsiveness. RT-PCR analysis revealed that CkGR was expressed in roofs, stems, and leaves with almost no tissue specificity. The transcript level of CkGR was increased in response to cold, high salt and drought stress. CkGR played an important role during cold, high salt and drought stress in Caragana korshinskii Kom..