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NAC转录因子在调控植物生长发育、生物及非生物逆境应答中发挥着重要作用。前期,我们通过对番茄幼苗在低温胁迫下的基因表达谱进行分析,发现Unigene SGN-U212711受低温诱导表达强烈。本研究从番茄中克隆了该基因,命名为Sl NAC41,其开放阅读框(ORF)1 173 bp,编码390个氨基酸,蛋白N端具有典型的NAM结构域,属于NAC转录因子家族成员。预测Sl NAC41蛋白分子量为43.5 k Da,等电点为5.2。实时荧光定量PCR分析表明,Sl NAC41在番茄各组织均有表达,在花中的表达量最高,在红熟果中的表达量最低。低温、干旱、高盐、甲基紫精(MV)、脱落酸(ABA)及乙烯利(ETH)处理均能诱导该基因的表达,其中,以低温和干旱诱导表达最为强烈。利用PLACE和Plant CARE对启动子序列进行预测分析发现,Sl NAC41启动子区含有大量响应光、病原菌侵染、激素、低温、脱水及盐胁迫的顺式作用元件。这些结果表明,Sl NAC41可能在番茄生物及非生物胁迫应答中发挥重要调控作用。
NAC transcription factors play an important role in the regulation of plant growth and development, biological and abiotic stress responses. In the early stage, we analyzed the gene expression profiles of tomato seedlings under low temperature stress and found that Unigene SGN-U212711 was strongly induced by low temperature. In this study, we cloned this gene from tomato and named Sl NAC41, which has a 1 173 bp open reading frame (ORF) encoding 390 amino acids. The N-terminal NNA protein is a member of NAC transcription factor family. Sl NAC41 protein is predicted to have a molecular weight of 43.5 kDa and an isoelectric point of 5.2. Real-time fluorescence quantitative PCR analysis showed that Sl NAC41 was expressed in all tissues of tomato, the highest expression was in flowers, and the lowest in red ripe fruits. Low temperature, drought, high salt, methyl viologen (MV), abscisic acid (ABA) and ethephon (ETH) treatment could induce the expression of this gene, of which, induced by low temperature and drought the most intense. Prediction of the promoter sequence using PLACE and Plant CARE revealed that the S1 NAC41 promoter region contains a large number of cis-acting elements that respond to light, pathogen infection, hormones, hypothermia, dehydration and salt stress. These results indicate that Sl NAC41 may play an important regulatory role in the biotic and abiotic stresses of tomato.