胡萝卜低温胁迫转录因子DcICE1基因克隆与非生物逆境响应分析

Cloning and Expression Profiles Analysis under Abiotic Stresses of Cold Stress Transcription Factor Gene DcICE1 from Daucus carota

植物ICE1基因是调控CBF基因表达的上游调控因子,在植物抵抗逆境胁迫中具有重要的作用。该实验以2个胡萝卜品种‘黑田五寸’和‘君川红’为实验材料,分别克隆出DcICE1转录因子基因,并通过荧光定量PCR方法测定了4种不同逆境胁迫下(4℃低温、38℃高温、0.2mol·L-1 NaCl及200g·L-1 PEG)DcICE1基因的表达情况,探讨DcICE1转录因子在植物抵抗非生物胁迫下的功能。序列分析显示,该基因全长1 458bp,编码485个氨基酸。2个胡萝卜品种的DcICE1基因在核苷酸水平上有2个位点的差异,分别为第139位的G/A和第475位的A/G,导致编码的氨基酸在第47位的E/K和第159位的N/D差异,该差异可能与DcICE1转录因子在2个不同品种应对逆境胁迫下的响应不同有关。胡萝卜DcICE1转录因子有一个保守的ICE1功能结构域。实时定量PCR检测DcICE1基因在不同逆境胁迫下的响应表明,低温(4℃)处理能明显地诱导DcICE1基因的表达,但盐(0.2mol·L-1 NaCl)和干旱(200g·L-1 PEG)处理下的诱导效果均不明显。

In higher plant, ICE1 involved in the response to abiotic and biotic stresses by regulating the ex- pression of CBF genes. The cDNA sequence of DcICE1 transcription factor was cloned from carrot cultivars ＇ Heitianwucun＇ and ＇Junchuanhong~ using RT-PCR method,respectively. In order to analyze the response of DcICE1 gene to abiotic stress,the expression profiles of DEICE1 gene in four different stresses（4 ℃ ,38 ℃ ,0.2 mol·L^-1 NaCI,200 g ·L^-1 PEG） were detected by quantitative real-time PCR. Sequence analysis indicated that the DcICE1 gene contained 1 458 bp,encoding 485 amino acids. There were two nucleotide sites and two amino acid residue differences between two cultivars（G/A in site 139 and A/G in site 475; E/K in site 47,N/D in 159）. The different amino acid residues may be involved into the different response in two carrot cultivars encountered the abiotic stresses. The DcICE1 transcription factor has a conserved domain. Quantitative real-time PCR detected the expression profiles of DcICE1 gene under abiotic stresses.The results showed the expression of DclCE1 gene significantly increased when exposed to 4 ℃ ,while the expression profiles of DcICE1 gene was not obvious after treated by salt and PEG in the two carrot cultivats.