[Exogenous IAA and ABA Stimulate Germination of Petunia Male Gametophyte by Activating Ca(2+)-Dependent K(+)-Channels and by Modulating the Activity of Plasmalemma H(+)-ATPase and Actin Cytoskeleton].

To date, the molecular mechanisms underlying the osmoregulation of pollen grains (PGs) related to the maintenance of their water status and allowing pollen tubes (PTs) to regulate concentrations in them of osmolytes and transmembrane water transport remain to be not so far characterized. In the present work, the data on the participation of IAA and ABA in the osmoregulation of germinating in vitro petunia male gametophyte were obtained. It has been established that the growth-stimulating effect of these phytohormones is due to their action on intracellular pH (pHc), the membrane potential of plasmalemma (PM), the activity of PM H(+)-ATPase, K(+)-channels in the same membrane and organization of actin cytoskeleton (AC).