Tracking Auxin Receptors Using Functional Approaches

Abstract

Abstract Functional approaches toward the identification of auxin receptors developed along two major lines: the isolation and characterization of mutants or transgenic plants affected in their responses to the hormone and the study of early auxin effects at the cell level such as expression of specific genes or modifications of plasma membrane properties. The combination of these approaches with those aiming at the molecular characterization of auxin binding proteins as putative auxin receptors allowed to bring further insight into the mechanisms of auxin perception by plant cells. Studies of membrane responses to auxin clearly demonstrated the existence of elementary response chains to auxin at the plasma membrane, the activation of auxin responsive proteins leading to changes in the membrane potential via the stimulation of the proton pump ATPase or the modulation of ion channels. A two-component model is proposed for the organization of functional auxin perception units at the plasma membrane, compris...