bHLH transcription factor that binds DNA on specific sequence 5'-CANNTG-3' in target gene promoters (PubMed:24009530). Negatively regulates brassinosteroid signaling (PubMed:20023194). Together with BHLH148/RITF1, regulates the transcription of several genes involved in the detoxification of reactive oxygen species (ROS) generated by salt (NaCl) stress. Confers tolerance to salt and to the oxidative stress-inducing reagents hydrogen peroxide H(2)O(2) and methyl viologen (MV) (PubMed:24009530). Homodimer (Probable). Interacts with PRE3. Binds to RSA1 (PubMed:24009530). Slightly induced by salt (NaCl) stress. Hypersensitivity to salt (NaCl) stress during seed germination and during seedling growth and development. Hypersensitivity to hydrogen peroxide H(2)O(2) and methyl viologen (MV).