Transcriptional activator which binds to the C-box-like motif 5'-TGACGT-3' and A-box-like motif 5'-GTACGTA-3' of target promoters to positively regulate the expression of genes involved in the tricarboxylic acid (TCA) cycle in response to nitrogen starvation (PubMed:28420744). May also regulate the TCA cycle during day-to-night transitions (PubMed:28420744). By nitrogen deficiency. Belongs to the bZIP family.