Pathways of the abscisic acid hormonal signal transduction across the plant cell plasma membrane.

Signal transduction pathways of a phytohormone abscisic acid (ABA) in the plant cell plasma membrane are reviewed. The mechanisms of ABA perception; ABA-induced alterations of Ca2+-, K+-, and anion channel activity, the ABA effects on intracellular pH and membrane-bound enzyme activity, as well as the phytohormone interaction with the lipid phase of plasma membrane are considered, and the role of the membrane protein phosphorylation is discussed. The available data suggest that the regulatory signal of ABA can be transmitted via a ramified chain of reactions. In different tissues, functioning of various branches of this chain can be independent or interrelated.