2月3日,國際期刊Evolution上在線發表了中科院武漢植物園植物應用基因組學學科組的研究成果,研究人員在植物NAC蛋白進化研究中取得了新進展。
NAC蛋白是植物中最大的轉錄因子家族之一,廣泛存在於陸生植物中。NAC蛋白參與植物生長發育和器官模式建成的許多特異方面。越來越多的研究表明,NAC蛋白在植物應答生物及非生物脅迫過程中發揮重要的作用。
博士研究生朱婷婷在彭俊華研究員的指導下,通過對9種陸生植物的全基因組序列檢索發現,在苔蘚和石松植物中NAC蛋白的數量小於30,而在被子植物中則多於100。系統發育分析表明,這些NAC蛋白由21個亞家族組成,在各亞家族中,NAC蛋白的轉錄激活區存在高度保守的基序,這些特異基序可能在NAC蛋白的進化過程中起著重要作用。研究還指出,NAC蛋白很有可能起源於4億年前,並隨著維管植物的分化而廣泛擴張。
與前人局限於被子植物的研究相比,該研究對更廣泛來源的植物全基因組數據進行分析,重新界定了NAC蛋白的亞家族以及各亞家族的特異性,並首次對NAC蛋白的進化史進行了探討。
該項研究得到國家自然科學基金重點項目、國家轉基因專項、中科院重要方向及973項目的資助。(生物谷Bioon.com)
Phylogenetic Analyses Uravel the Evolutionary History of NAC Proteins in Plants
Tingting Zhu, Eviatar Nevo, Dongfa Sun, Junhua Peng
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.