A chickpea NAC-type transcription factor, CarNAC6, confers enhanced dehydration tolerance in Arabidopsis

Plant growth and productivity are inhibited by environmental stresses such as drought, salinity, and cold. NAC transcription factors play essential roles in response to the stresses. Chickpea ( Cicer arietinum L.) is an important legume crop, which has strong resistance to abiotic stresses. In this study, a chickpea NAC gene, CarNAC6 , was isolated and functionally characterized. CarNAC6 is a member of TERN subfamily, which contains a typical NAC conserved domain located in the N-terminal region and a transactivation activity region in the C-terminal region. Subcellular localization of CarNAC6-GFP fusion protein indicated that CarNAC6 protein is a nuclear protein. In the yeast assay system, CarNAC6 acts as a transcriptional activator, and its transactivation domain is located in the C-terminus. Electrophoretic mobility shift assay and yeast one-hybrid assay indicated that CarNAC6 can bind to CGT[G/A]. Overexpression of CarNAC6 in transgenic Arabidopsis confers enhanced tolerance to drought and promotes root growth under salt stress. Moreover, CarNAC6 overexpression plants are hypersensitive to ABA during root growth stage. All these results suggested that CarNAC6 functions as a stress-responsive NAC-type transcription factor in chickpea and has potential for utilization in stress-tolerance engineering in crops.