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. Binds to the 5'-ACGT-3' motif of seed storage protein (SSP) encoding gene promoters (e.g. At2S and CRU3) and promotes their expression in seeds when in complex with ABI3 and BZIP53. Involved in the defense responses to the biotrophic pathogen Hyaloperonospora parasitica and oxidative stress responses; mediates positively cell death (PubMed:12657652, PubMed:16957775, PubMed:19261733, PubMed:19531597). Promotes BZIP53-mediated response to hypoosmolarity stress that leads to POX1/PRODH1 accumulation (PubMed:16810321). Forms a heterodimer with BZIP1, BZIP2, BZIP9, BZIP11, BZIP44, BZIP53 and BZIP63. Interacts with ABI3 and forms a complex made of ABI3, BZIP53 and BZIP10. Binding with LSD1 leads to cytoplasmic retention. Shuttles between the nucleus and the cytoplasm. Retained outside the nucleus by LSD1 to prevent cell death. Expressed in roots, shoots, stems, young leaves, trichomes, hydathodes, siliques, seeds, and flowers, mostly in vascular tissues. First observed in carpels and seeds at early stages of development, mostly in embryo and, at lower extent, in the endosperm. Accumulates and peaks at maturation. Fade out during late seed development steps, restricted to the inner layer of the seed coat, and, at very low levels, in the mature embryo and the remaining endosperm. Also present in the lignified inner subepidermal layer of the valves. In the anthers, restricted to the connective tissue at pre- and post-dehiscence stages and detected in the vascular tissue of the stamen filament. Belongs to the bZIP family.