Transcriptome-wide identification and expression analysis of the NAC gene family in lowland bamboo (Oxytenanthera abyssinica (A.Rich) Munro)under abiotic stresses

Abstract

NAC (NAM, no apical meristem, ATAF and CUC) is one of the largest gene families of the plant-specific transcription factors (TF). NAC TFs have immense involvement in plant growth and developmental processes and have particular importance in enhancing plant resistance to multiple abiotic stresses. NAC members have unique structural makeup and a range of biological activities. Despite their enormous roles in plants, comprehensive study on identification, characterization and expression profiling of NACs under abiotic stress is lacking in Lowland bamboo [Oxytenanthera abyssinica (A.Rich) Munro]. Thus, this study aimed to identify NAC members, characterize their protein properties, construct their phylogenetic relationships and more importantly, establish their expression profiling under abiotic stress. From this abiotic stress-induced transcriptome, 220 lowland bamboo TFs with intact and complete NAC DNA binding domains (PF01849) were identified. Following their identification, analysis of functional annotation, protein characterization, phylogenetic relationships and expression profiling were conducted. The analysis presented up-regulation of 142 unigenes in response to abiotic stress, the association of 26 unigenes directly to stress response and the involvement of 92 unigenes in genetic information processing and 29 in environmental information processing according to KEGG analysis. These results suggest the most likely involvement of NACs in lowland bamboo stress response and adaptation. As a species best survived in a moisture-stressed environment, this study has provided valuable information that could shed light on further functional analysis research efforts aiming to exploit NACs in developing stress-resilient bamboo and related plants.