Functions as transcriptional activator in the ABA-inducible expression of LTI65/RD29B (AC Q04980). Binds specifically to the ABA-responsive element (ABRE) of the LTI65/RD29B (AC Q04980) gene promoter (PubMed:11005831, PubMed:11884679, PubMed:15361142, PubMed:16463099). Binds to the promoter of FREE1 and activates its transcription (PubMed:32540007). DNA-binding heterodimer (By similarity). Interacts with CPK32 and the AFP proteins AFP1, AFP2 and AFP3. Interacts with FREE1 (via C-terminus) (PubMed:30962512). A number of isoforms are produced. According to EST sequences. Expressed in roots, leaves, flowers and immatures siliques. Up-regulated by drought, salt, abscisic acid (ABA) and cold. Phosphorylated by CPK4 and CPK11 in vitro. Defective in ABA and stress responses. Belongs to the bZIP family. ABI5 subfamily.