Nopaline Synthase (nos) Promoter From T-DNA - This promoter is 200 bp long and contains several DNA sequence motifs which direct the expression of linked gene. The upstream element from - 97 to - 130, when duplicated, increases the expression three fold, suggesting that this may be an enhancer.

The nos promoter is most active in basal regions of plants, its activity slowing down in vegetative parts at the onset of flowering, even though in the flower its activity is increased.