Transcription factor of the NAC family associated with the grain protein content (GPC). Accelerates senescence and increases nutrient remobilization from leaves to developing grains. The tetraploid cultivated wheat (T.durum) contains one additional gene coding for a functional protein (NAM-B2) and one extra pseudogene (NAM-B1) (PubMed:17124321). Expressed in flag leaves, green spikes and peduncles. Increased expression during grain maturation. The NAC domain includes a DNA-binding domain and a dimerization domain. No visible phenotype, but higher chlorophyll content and delayed senescence. High grain protein content (GPC) is a desirable trait in breadmaking and pasta wheat varieties because of its positive effects on quality and nutritional value while Low GPC is a desirable trait for barley malt and beer production.