Inhibition of elongation and H(+) and K (+) transport by the phosphodiesterase inhibitor aminophylline in plant tissue.

Aminophylline, an inhibitor of cyclic nucleotide phosphodiesterase (EC 3.1.4.17), inhibits elongation and correlated H(+) and K(+) transport in embryos of Haplopappus gracilis and in pea internode segments. Moreover, the drug strongly inhibits the stimulation of these processes by fusicoccin and indole-3-acetic acid and reduces passive permeability of the membrane. The possible mechanisms of action of aminophylline are discussed.