番茄NAC转录因子SlNAC80的克隆及表达分析

Cloning and Expression Analysis of a NAC Transcription Factor Sl NAC80 in Tomato

为进一步明确该基因的分子特征及表达特性,通过RT-PCR从番茄中克隆了低温响应NAC转录因子SlNAC80,该基因开放阅读框1 023 bp,编码340个氨基酸。Sl NAC80蛋白相对分子量为38.19 k Da,等电点为5.27,N-端具有典型的NAC保守结构域,包含A、B、C、D、E 5个亚结构域。实时荧光定量PCR(q PCR)分析表明,Sl NAC80在番茄各组织中均有表达,以在绿果和衰老叶中的表达量最高,在红熟果中的表达量最低。对启动子区序列进行预测分析发现,Sl NAC80启动子区含有许多响应激素(ABA、GA、SA及ETH)和逆境(低温、脱水及盐胁迫)的顺式作用元件,如ERELEE4、GARE1OSREP1、LTRE1HVBLT49、GT1GMSCAM4、MYB1AT、MYCATERD1、MYCATRD22、WBOXNTERF3及WRKY71OS等。q PCR分析结果也证实该基因的表达受低温、干旱、高盐、甲基紫精、ABA及乙烯处理诱导。这些结果表明,Sl NAC80可能在番茄非生物逆境应答中发挥重要调控作用。

To further understand the molecular characterization and expression patterns of SlNAC80,we cloned this gene from tomato SlNAC80 contains an open reading frame of 1 023 bp encoding a protein of 340 amino acids . The molecular weight and isoelectric point of SlNAC 80 protein was 38.19 kDa and 5.27,respectively.SlNAC80 contains a typical NAC domain in the N-terminal,which consists of five subdomains （A to E）.Quantitative Real-time PCR （qPCR） analysis showed that SlNAC80 was expressed in all tested tomato tissues ,with the highest in green fruits and old leaves ,and the lowest in red ripe fruits .Promoter sequence analysis indicated that there were many cis-acting regulatory elements involved in response to hormones （ABA,GA,SA and ETH） and abiotic stresses （cold, dehydration and salt stresses ）, such as ERELEE4, GARE1OSREP1, LTRE1HVBLT49, GT1GMSCAM4, MYB1AT,MYCATERD1,MYCATRD22,WBOXNTERF3,WRKY71OS,and etc.The qPCR analysis also demonstra-ted that the expression of SlNAC80 was induced by cold,drought,salt,methyl viologen,ABA and ethephon treat-ments .These results suggest that SlNAC80 may play important roles in regulating abiotic stress responses in tomato .