香樟两个DREB1转录因子基因的分离及其对不同胁迫的响应分析

以香樟（Cinnamomum camphora）实生苗为试验材料，利用同源克隆结合RACE技术获得了两个冷诱导转录因子基因CBF/DREB1的cDNA全长序列，命名为CcCBFc和CcCBFd，GenBank登录号分别为KP336741和KP336742。序列分析显示这两个基因均没有内含子，cDNA全长为897和1 010 bp，开放阅读框分别为654和621 bp，编码217和206个氨基酸，预测蛋白分子量分别为24.0和22.9 kD，等电点分别为5.26和8.58。基于氨基酸序列的同源性比对和系统进化树分析表明，这两个基因均属于DREB1家族，与双子叶植物进化关系较近。实时定量PCR结果显示，CcCBFc和CcCBFd都能被低温（4 ℃）、干旱（20%PEG）、盐（250 mmol ? L-1 NaCl）和ABA（100 μmol ? L-1）诱导，表明CcCBFc和CcCBFd可能在香樟应对非生物胁迫过程中发挥重要作用。

Isolation and Expression Profiles Analysis of Two DREB1 Transcription Factor Genes Under Different Stresses in Cinnamomum camphora

Two CBF/DREB1 genes named CcCBFc and CcCBFd were isolated from Cinnamomum camphora with the help of homologous cloning strategy and RACE（rapid amplification of cDNA ends）technique，and their GenBank accession numbers are KP336741 and KP336742，respectively. The full-length cDNA sequences of the two CcCBF genes were 897 and 1 010 bp，including an open reading frame（ORF）of 654 and 621 bp，respectively，and no introns existed in their coding regions. The CcCBFc and CcCBFd genes encode 217 and 206 amino acids with predicted molecular masses of 24.0 and 22.9 kD，and pI of 5.01 and 5.11. CcCBFc and CcCBFd were classified into the CBF/DREB1 subfamily，and had relatively close evolutionary relationship with dicotyledons，according to the homology comparison and phylogeny tree analysis of the deduce amino acids sequences with other CBF/DREB homologues. The expression level of both CcCBFc and CcCBFd could be upregulated by all tested treatments such as cold （4 ℃），drought（20% PEG），salinity（250 mmol ? L-1 NaCl）and ABA（100 μmol ? L-1）. The observations presented in this study might indicate that both CcCBFc and CcCBFd were involved in response to various abiotic stresses.