Wang Yuan, Gao Yan-Hui, Zhu Yu-Qiu, Si Jin-Ping
Dendrobium State Forestry Engineering Research Center,State Key Laboratory of Subtropical Silviculture,Zhejiang A & F Universiy Lin'an 311300,China.
Zhongguo Zhong Yao Za Zhi. 2019 Jan;44(2):293-297. doi: 10.19540/j.cnki.cjcmm.20181106.005.
DcCDPK8 involved in abiotic stress such as low temperature and signal transduction of hormones ABA and MeJA,but the transcriptional regulation is still unclear. In order to study the core promoter region of DcCDPK8 gene in Dendrobium catenatum and explore its transcriptional regulation mechanism,the DcCDPK8 gene promoter sequence was cloned by PCR from D. catenatum. Promoter sequence function was studied by fusion of 5 'terminal deletion and GUS gene. The results showed that the promoter sequence of DcCDPK8 gene has a low-temperature responsive element( LTR) between(-1) 749 bp and-614 bp,two MeJA responsive elements between(-1) 749 bp and-230 bp,and one ABA responsive elements between-614 bp and-230 bp. Three 5'-end different deletion fragments were constructed to fuse the eukaryotic expression vectors p BI121 with GUS,which were transformed into tobacco leaves. The GUS activity under cold stress treatment was DcCDPK8-p1>DcCDPK8-p2>DcCDPK8-p3. GUS activity under exogenous ABA induction was DcCDPK8-p1>DcCDPK8-p2>DcCDPK8-p3,and GUS activity under exogenous MeJA induction was DcCDPK8-p1>DcCDPK8-p2>DcCDPK8-p3. It is speculated that the ABA response element( ARE) in the promoter sequences of DcCDPK8 is positive regulatory role in response to exogenous ABA,the MeJA cis-acting element plays a negative role in response to exogenous MeJA.
石斛DcCDPK8参与低温等非生物胁迫以及激素脱落酸（ABA）和茉莉酸甲酯（MeJA）的信号转导，但其转录调控仍不清楚。为了研究金线莲DcCDPK8基因的核心启动子区域并探索其转录调控机制，通过PCR从金线莲中克隆了DcCDPK8基因启动子序列。通过5'末端缺失与GUS基因融合研究启动子序列功能。结果表明，DcCDPK8基因启动子序列在约-1749 bp至-614 bp之间有一个低温响应元件（LTR），在约-1749 bp至-230 bp之间有两个MeJA响应元件，在-614 bp至-230 bp之间有一个ABA响应元件。构建了三个5'端不同缺失片段与GUS融合的真核表达载体pBI121，并转化到烟草叶片中。冷胁迫处理下的GUS活性为DcCDPK8-p1>DcCDPK8-p2>DcCDPK8-p3。外源ABA诱导下的GUS活性为DcCDPK8-p1>DcCDPK8-p2>DcCDPK8-p3，外源MeJA诱导下的GUS活性为DcCDPK8-p1>DcCDPK8-p2>DcCDPK8-p3。推测DcCDPK8启动子序列中的ABA响应元件（ARE）对外源ABA响应起正调控作用，MeJA顺式作用元件对外源MeJA响应起负调控作用。
