State Key Laboratory of Crop Stress Biology for Arid Areas, and College of Life Sciences, Northwest A & F University, Yangling, 712100, Shaanxi, China,
Plant Mol Biol. 2015 Mar;87(4-5):395-411. doi: 10.1007/s11103-015-0286-1. Epub 2015 Jan 24.
NAC transcription factors are plant-specific and play important roles in plant development processes, response to biotic and abiotic cues and hormone signaling. However, to date, little is known about the NAC genes in canola (or oilseed rape, Brassica napus L.). In this study, a total of 60 NAC genes were identified from canola through a systematical analysis and mining of expressed sequence tags. Among these, the cDNA sequences of 41 NAC genes were successfully cloned. The translated protein sequences of canola NAC genes with the NAC genes from representative species were phylogenetically clustered into three major groups and multiple subgroups. The transcriptional activities of these BnaNAC proteins were assayed in yeast. In addition, by quantitative real-time RT-PCR, we further observed that some of these BnaNACs were regulated by different hormone stimuli or abiotic stresses. Interestingly, we successfully identified two novel BnaNACs, BnaNAC19 and BnaNAC82, which could elicit hypersensitive response-like cell death when expressed in Nicotiana benthamiana leaves, which was mediated by accumulation of reactive oxygen species. Overall, our work has laid a solid foundation for further characterization of this important NAC gene family in canola.
NAC 转录因子是植物特有的，在植物发育过程、对生物和非生物线索的反应以及激素信号转导中发挥重要作用。然而，迄今为止，关于油菜（或油菜籽，Brassica napus L.）中的 NAC 基因知之甚少。在这项研究中，通过系统分析和挖掘表达序列标签，从油菜中总共鉴定出 60 个 NAC 基因。其中，成功克隆了 41 个 NAC 基因的 cDNA 序列。油菜 NAC 基因与代表物种的 NAC 基因的翻译蛋白序列被系统发育聚类为三个主要组和多个亚组。这些 BnaNAC 蛋白的转录活性在酵母中进行了测定。此外，通过定量实时 RT-PCR，我们进一步观察到，这些 BnaNAC 中的一些受到不同激素刺激或非生物胁迫的调节。有趣的是，我们成功鉴定了两个新的 BnaNACs，BnaNAC19 和 BnaNAC82，当在 Nicotiana benthamiana 叶片中表达时，它们可以引发类似过敏反应的细胞死亡，这是由活性氧的积累介导的。总的来说，我们的工作为进一步研究油菜中这个重要的 NAC 基因家族奠定了坚实的基础。
