The Effect of the Plant Hormone Abscisic Acid on Lipid Bilayer Membranes

Summary In the presence of the plant hormone 2‐cis,4‐transabscisic acid, bimolecular lipid membranes exhibited conductance fluctuations of the type associated with channels. Under a voltage clamp of 100 mV, channels were observed of mean conductance 0‐4 × 10−10S and mean lifetime 0·2 msec. Membrane conductance was measured as a function of concentration of abscisic acid and a log‐log plot of the data revealed a linear relationship. The slope of the regression line was 0·52 ± 0·08 with Pearson's product moment 0·85. An analysis of current fluctuations is presented. The results are discussed in terms of a process in which multimeric channels are generated from abscisic acid monomers and in which channels are destroyed by collision.