The Arabidopsis NAC Transcription Factor ANAC096 Cooperates with bZIP-Type Transcription Factors in Dehydration and Osmotic Stress Responses

• Published in: The Plant cell 2013-11, Vol.25 (11), p.4708-4724
• Main Authors: Xu, Zheng-Yi, Kim, Soo Youn, Hyeon, Do Young, Kim, Dae Heon, Dong, Ting, Park, Youngmin, Jin, Jing Bo, Joo, Se-Hwan, Kim, Seong-Ki, Hong, Jong Chan, Hwang, Daehee, Hwang, Inhwan
• Format: Article
• Language: English
• Subjects: Abscisic Acid - metabolism; Abscisic Acid - pharmacology; Arabidopsis - drug effects; Arabidopsis - growth & development; Arabidopsis - physiology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Base Sequence; Basic-Leucine Zipper Transcription Factors - genetics; Basic-Leucine Zipper Transcription Factors - metabolism; Cell Nucleus - metabolism; Dehydration; DNA; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Gene Expression Regulation, Plant - drug effects; Genes; Germination - drug effects; Molecular Sequence Data; Mutation; Osmotic Pressure; Plant cells; Plants; Plants, Genetically Modified; Polymerase chain reaction; Promoter regions; Promoter Regions, Genetic; Protoplasts; Stress, Physiological; Transcription factors; Transcription Factors - genetics; Transcription Factors - metabolism; Transgenic plants
• ISSN: 1040-4651; 1532-298X
• DOI: 10.1105/tpc.113.119099

Multiple transcription factors (TFs) play essential roles in plants under abiotic stress, but how these multiple TFs cooperate in abiotic stress responses remains largely unknown. In this study, we provide evidence that the NAC (for NAM, ATAF1/2, and CUC2) TF ANAC096 cooperates with the bZIP-type TFs ABRE binding factor and ABRE binding protein (ABF/AREB) to help plants survive under dehydration and osmotic stress conditions. ANAC096 directly interacts with ABF2 and ABF4, but not with ABF3, both in vitro and in vivo. ANAC096 and ABF2 synergistically activate RD29A transcription. Our genome-wide gene expression analysis revealed that a major proportion of abscisic acid (ABA)—responsive genes are under the transcriptional regulation of ANAC096. We found that the Arabidopsis thaliana anac096 mutant is hyposensitive to exogenous ABA and shows impaired ABA-induced stomatal closure and increased water loss under dehydration stress conditions. Furthermore, we found the anac096 abf2 abf4 triple mutant is much more sensitive to dehydration and osmotic stresses than the anac096 single mutant or the abf2 abf4 double mutant. Based on these results, we propose that ANAC096 is involved in a synergistic relationship with a subset of ABFs for the transcriptional activation of ABA-inducible genes in response to dehydration and osmotic stresses.