摘要
Dear Editor The NAC （for NO APICAL MERISTEM [NAM], Arabidopsis TRANSCRII^TION ACTIVATOR FACTOR [ATAF] and CUP- SHAPED COTYLEDON [CUC]） proteins are one of the largest families of plant-specific transcription factors （Nagata et aL, 2015）. They are involved in many different biological processes including development and the response to biotic and abiotic stresses. To date, NAC transcription factors have only been identified in land plants （Zhu et al., 2012; Nagata et al., 2015）; and some of them control land-plant-specific processes, such as the formation of specialized water-conducting systems （Xu et al., 2014）. Therefore, it has been suggested that their appearance accompanied the emergence of land plants. Here, we exploited the transcriptomic data generated within the 1000 plants project （www.onekp.com, Wickett et al., 2014） to revisit the origin of NAC proteins. Our careful analysis shows that NAC transcription factors appeared before the ernergence of land plants as we detected their homologs in several groups of streptophyte green algae. The possible significance of this finding is discussed.
Dear Editor The NAC （for NO APICAL MERISTEM [NAM], Arabidopsis TRANSCRII^TION ACTIVATOR FACTOR [ATAF] and CUP- SHAPED COTYLEDON [CUC]） proteins are one of the largest families of plant-specific transcription factors （Nagata et aL, 2015）. They are involved in many different biological processes including development and the response to biotic and abiotic stresses. To date, NAC transcription factors have only been identified in land plants （Zhu et al., 2012; Nagata et al., 2015）; and some of them control land-plant-specific processes, such as the formation of specialized water-conducting systems （Xu et al., 2014）. Therefore, it has been suggested that their appearance accompanied the emergence of land plants. Here, we exploited the transcriptomic data generated within the 1000 plants project （www.onekp.com, Wickett et al., 2014） to revisit the origin of NAC proteins. Our careful analysis shows that NAC transcription factors appeared before the ernergence of land plants as we detected their homologs in several groups of streptophyte green algae. The possible significance of this finding is discussed.
