Interaction of abscisic-acid-binding cotton (Gossypium hirsutum) protein and phytohormones

Abstract

The interaction of representatives of three classes of phytohormones, abscisic acid (ABA), the synthetic auxin 1-NAA, and the synthetic cytokinin 6-BAP, with ABA-binding cotton protein was studied. Binding of ABA with its protein was shown to be specific and receptor-like. Competitive protein binding showed that 1-NAA (15±3%), 6-BAP (82±3%), and ABA (95±3%) replace3H-ABA from the protein complex. The possibility of reacting ABA-binding protein with various classes of intracellular phytohormones is discussed.