Genomics, Molecular and Evolutionary Perspective of NAC Transcription Factors

NAC (NAM, ATAF1,2, and CUC2) transcription factors are one of the largest transcription factor families found in plants and are involved in diverse developmental and signalling events. Despite the availability of comprehensive genomic information from diverse plant species, the basic genomic, biochemical, and evolutionary details of NAC TFs have not been established. Therefore, NAC TFs family proteins from 160 plant species were analyzed in the current study. The analysis, among other things, identified the first algal NAC TF in the Charophyte, Klebsormidium flaccidum. Furthermore, our analysis revealed that NAC TFs are membrane bound and contain monopartite, bipartite, and multipartite nuclear localization signals. NAC TFs were also found to encode a novel chimeric protein domain and are part of a complex interactome network. Synonymous codon usage is absent in NAC TFs and it appears that they have evolved from orthologous ancestors and undergone significant duplication events to give rise to paralogous NAC TFs.