Component of the NF-Y/HAP transcription factor complex. The NF-Y complex stimulates the transcription of various genes by recognizing and binding to a CCAAT motif in promoters. Acts as a central regulator of the embryogenesis. Required for the speciation of cotyledon identity and the completion of embryo maturation. Controls seed storage protein genes through the regulation of FUS3 and ABI3. Involved in the blue light (BL) and abscisic acid (ABA) signaling pathways. Heterotrimeric transcription factor composed of three components, NF-YA, NF-YB and NF-YC. NF-YB and NF-YC must interact and dimerize for NF-YA association and DNA binding (By similarity). Interacts with PRN1. Expressed in green siliques. Present in etiolated seedlings. Accumulates during seed development in embryo cell types and in endosperm tissue. Altered response to blue light (BL) and abscisic acid (ABA). Belongs to the NFYB/HAP3 subunit family. Truncated N-terminus.