黄瓜转录因子CsCBF3 的克隆及表达分析

利用RT-PCR 技术从黄瓜中克隆了植物低温信号转导途径中的关键转录因子C-repeat-Binding
Factor3，将其命名为CsCBF3，GenBank 登录号为JQ900769。CsCBF3 基因开放阅读框全长为615 bp，
编码204 个氨基酸。进化树分析表明，CsCBF3 隶属于CBF 基因家族，与葡萄CBF3 蛋白亲缘关系最近，
而与黑麦草、水稻CBF3 蛋白亲缘关系较远。生物信息学分析结果表明，CsCBF3 编码的蛋白包含保守的
AP2 DNA 结合域，N 端的核定位信号区和C 端的酸性氨基酸富集区，且该蛋白中的一些磷酸化位点及二
级结构在与DNA 互作过程中发挥重要作用。荧光定量PCR 检测结果显示低温可诱导CsCBF3 的表达，且
其表达量在迅速达到峰值后又降低，说明CsCBF3 是一个快速响应基因，推测其在黄瓜耐冷过程中起着重
要的作用。

Cloning and Expression Analysis of Transcription Factor CsCBF3 Gene from Cucumber

In order to determine its role in cold response in cucumber（ Cucumis sativus
L.），CsCBF3 was cloned from Chipper using RT-PCR method and its GenBank accession number
was JQ900769．CsCBF3 had an open reading frame of 615 bp，which was supposed to encode
a protein of 204 amino acids．Phylogenetic tree analyses showed that CsCBF3 belonged to CBF
gene family and had close relationship with CBF3 from Vitis amurensis，while had far relationship
with CBF3 from Lolium perenne and Oryza sativa．Bioinformatics analysis showed that CsCBF3
protein was consisted of AP2 DNA binding domain，which included amino acid residues，nuclear
localization signal region and acidic activation domain，and some phosphorylation sites and protein
secondary structures may play important roles in process of interactions between proteins and
DNA．Quantitative real-time PCR results showed that expression of CsCBF3 could be induced
by low temperature，and the level reached to peak very fast and then decreased．These results
suggested that CsCBF3 was a rapid response gene and played an important role in resistance to low
temperature in cucumber.