Transcription factor directing sieve element enucleation and cytosol degradation. Not required for formation of lytic vacuoles. Regulates, with NAC086, the transcription of NEN1, NEN2, NEN3, NEN4, RTM1, RTM2, UBP16, PLDZETA, ABCB10 and At1g26450. Expressed in a few sieve element cells before enucleation and in phloem-pole pericycle cells. Regulated by the transcription factor APL (AC Q9SAK5). The NAC domain includes a DNA binding domain and a dimerization domain. No visible phenotype, due to the redundancy with NAC086 (AC Q9FFI5). Nac045 and nac086 double mutants exhibit seedling lethality with defective development of the protophloem sieve element.