A, NIP1-binding site in different cereals. Equilibrium competition-binding experiments were carried out using microsomal membranes from barley (•), wheat (▪), rye (▵), oat (♦), maize (⋄), and Arabidopsis (○). B, Normalized competition data with the dotted lines showing the competition curves for rye with the lowest and maize with the highest IC50 value, whereas the solid line represents barley. For transparency reasons, error bars are not shown.