Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture and Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, Hubei 430074, China.
Evolution. 2012 Jun;66(6):1833-48. doi: 10.1111/j.1558-5646.2011.01553.x. Epub 2012 Feb 3.
NAC (NAM/ATAF/CUC) proteins are one of the largest groups of transcription factors in plants. Although many NAC proteins based on Arabidopsis and rice genomes have been reported in a number of species, a complete survey and classification of all NAC genes in plant species from disparate evolutionary groups is lacking. In this study, we analyzed whole-genome sequences from nine major lineages of land plants to unveil the relationships between these proteins. Our results show that there are fewer than 30 NAC proteins present in both mosses and lycophytes, whereas more than 100 were found in most of the angiosperms. Phylogenetic analyses suggest that NAC proteins consist of 21 subfamilies, most of which have highly conserved non-NAC domain motifs. Six of these subfamilies existed in early-diverged land plants, whereas the remainder diverged only within the angiosperms. We hypothesize that NAC proteins probably originated sometime more than 400 million years ago and expanded together with the differentiation of plants into organisms of increasing complexity possibly after the divergence of lycophytes from the other vascular plants.
NAC（NAM/ATAF/CUC）蛋白是植物中最大的转录因子家族之一。尽管已经在许多物种中报道了基于拟南芥和水稻基因组的许多 NAC 蛋白，但对来自不同进化群体的植物物种中所有 NAC 基因的完整调查和分类仍然缺乏。在这项研究中，我们分析了来自九大陆地植物谱系的全基因组序列，以揭示这些蛋白之间的关系。我们的结果表明，在苔藓植物和石松植物中，NAC 蛋白的数量少于 30 个，而在大多数被子植物中则发现了 100 多个。系统发育分析表明，NAC 蛋白由 21 个亚家族组成，其中大多数具有高度保守的非-NAC 结构域基序。这六个亚家族存在于早期分化的陆地植物中，而其余的亚家族仅在被子植物中分化。我们假设 NAC 蛋白可能起源于 4 亿多年前，并且随着植物向越来越复杂的生物分化而与植物一起扩张，可能在石松植物与其他维管植物分化之后。
