In the presence of the plant hormone 2-cis,4-trans abscisic 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 × 10−10 S 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.