Transcriptome wide identification and characterization of NAC Transcription factors in response to abiotic stress in Lowland bamboo [ Oxytenanthera abyssinica (A.rich) munro]

Abstract NAC (NAM, no apical meristem, ATAF and CUC) are among the biggest plant transcription factor (TF) having important role in plant developmental and biological processes. NAC members which are found only in plant kingdom have distinct structures and diverse functions. They have tremendous role in cell differentiation and expansion, and hormone signaling in response to various stresses. Despite this importance, genome-wide analysis and expression profiling of NAC gene family under abiotic stress remains elusive in Ethiopian lowland bamboo (Oxytenanthera abyssinica). In this study, a genome-wide identification of 220 O. abyssinica TFs having intact and complete NAC DNA binding domain (PF01849) have been made from abiotic stress induced transcriptome. The identification was followed by functional annotation, protein property, phylogenetic relationship and expression profiling. Accordingly, significant variations were observed regarding gene length, molecular weights and isoelectric points among NAC members. The expression level of randomly selected OaNACs were examined using qRT-PCR. The results were consistent with the RNA-Seq results, confirming the differential expression of selected genes. This informs the key role of NACs in regulating abiotic stress tolerances in O. abyssinica. In total, 142 of the 220 OaNACs are differentially expressed due to either drought or salinity stress. The biological involvement of 26 genes in stress response and the up-regulation 35 genes in expression analysis points the likely association of NACs in stress response and adaption in O. abyssinica. In this regard, this study lays the basis for further studies associated with NACs abiotic stress tolerance and adaptation in O. abyssinica and related plants.