Transcription factor that binds to the C-box-like motif (5'-TGCTGACGTCA-3') and G-box-like motif (5'-CCACGTGGCC-3'), ABRE elements, of gene promoters involved in sugar signaling. Activated by low energy stress both at transcriptional and post-transcriptional mechanisms. Promotes dark-induced senescence and participates in the transcriptional reprogramming of amino acid metabolism during the dark-induced starvation response (PubMed:20080816, PubMed:21278122). Transcription activator of the mannan synthase CSLA9. Recognizes and binds to DNA-specific sequence of CSLA9 promoter (PubMed:24243147). Interacts with ZFP7, BZIP4, BZIP9, BZIP10, BZIP11, BZIP25, BZIP42, BZIP44, BZIP53, BZIP58 and BZIP63. Expressed in both shoots, including young leaves, stipulae and trichomes (except in cotyledons and hypocotyl), and roots, including vascular tissues (e.g. in both the phloem and the xylem). Present in seeds and pollen. Restricted to vasculatures and roots in the presence of sucrose or glucose. Expressed in seeds during late stage of development. Reversibly repressed by glucose and mannose. Slowly induced by Pseudomonas syringae. Induced in roots upon cold and salt stress but then repressed in leaves. Promoted by low energy stress and dark-induced starvation. Reduced requirement for exogenous sugar for seedling growth and higher rates of true leaf development. Belongs to the bZIP family.