Poster: Signaling, long distance

Abs # 457: Bioelectrochemical Signaling in Green Plants: Effects of Abscisic Acid on Soybean

Presenter:	Ranatunga, Don Rufus A., donranatunga@oakwood.edu
Authors	Ranatunga, Don Rufus A. (A)   Shelly, Alicia D. (A)   Davis, Sonnet  (A)   Denham, Shalleen-Kay  (A)   Volkova, Maia  (A)   Volkov, Alexander G. (A)
Affiliations:	(A): Oakwood College

Plants have a specific property known as excitability in which cells and tissues change their internal condition and external reactions under the influence of various environmental changes. This stimulus-induced change in plasma membrane potential in higher plants measured as action potentials could be the information carriers in intracellular and intercellular communication during such changes. The role of abscisic acid (ABA) as a growth inhibitor in green plants has long been recognized. When the plant is under environmental stress, ABA causes stomatal closure by inducing rapid depolarization events as a result of activation of calcium channels due to the release of cytosolic calcium into the cytosol. In this work, the propagation of excitation waves induced due to exogenous addition of ABA in soybean plants has been investigated. After addition of ABA solution, electrochemical signals are recorded from plants interfaced with an IBM-compatible computer with a Keithley data acquisition board. It was found that a series of potential differences was observed approximately 22 hours after the addition of 5 x 10-4 M of ABA. It is suggested that the exogenous stimulus of ABA causes a slow efflux of calcium that will eventually induce a potential difference. This work is supported by the National Science Foundation Grant HRD-9908993.