Poster: Tropisms

Abs # 402: Electrophysiology of phototropism

Presenter:	Volkov, Alexander G, gvolkov@oakwood.edu
Authors	Volkov, Alexander G (A)   Dunkley, Tanya  (A)   Labady, Anthony  (A)
Affiliations:	(A): Oakwood College

Plants generate various types of extracellular electrical events in connection to environmental stress. The generation of electrophysiological responses induced by blue and red photosensory systems was observed in soybean plants. A phototropic response is a sequence of the four following processes: reception of a directional light signal, signal transduction, transformation of the signal into a physiological response, and the production of a directional growth response. It was found that the irradiation of soybean plants at 450 ± 50 nm produces action potentials with duration times and amplitudes of approximately 0.3 ms and 60 mV respectively. Effects of Ca and K voltage gated ion channels on phototropism were studied in detail. K and Ca channel blockers dramatically decrease the phototropic response.