title: Electrical potential oscillations--movement relations in circumnutating sunflower stem and effect of ion channel and proton pump inhibitors on circumnutation.
abstract: The physiological control and molecular mechanism of circumnutation (CN) has not yet been fully understood. To gain information on the CN mechanism, the relationship between the changes of electrical potential and movement in the circumnutating sunflower stem and effect of ion channels and proton pump inhibitors on CN parameters were evaluated. Long-term electrophysiological measurements and injection of solutions of ion channel inhibitors (ICI) into sunflower stem with the simultaneous time-lapse recording of the movement were made. The oscillations of electrical potential (OEP) - movement relations - consist of cells depolarization on the deflected side of the stem and, at this same time, cells hyperpolarization on the opposite side of the stem. The delay of organ movement in relation to electrical changes of approximately 28 min (22% of the period) may indicate that the ionic fluxes causing the OEP are the primary phenomenon. The biggest decrease of CN period was observed after injection of proton pump (approximately 26%) and cation channel (approximately 25%) inhibitors, while length and amplitude were reduced mainly by calcium channel inhibitors (approximately 67%). Existence of OEP only in circumnutating part of sunflower stem and reduction of CN parameters and OEP amplitude after application of ICI prove that the CN cellular mechanism is associated with transmembrane ion transport.
authors.affiliation: Department of Biophysics, Institute of Biology and Biochemistry, Maria Curie-Sklodowska University, 20-033, Lublin, Poland; Institute of Agrophysics, Polish Academy of Sciences, 20-290, Lublin, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Kurenda
authors.forename: Maria
authors.initials: M
authors.lastname: Stolarz
authors.forename: Artur
authors.initials: A
authors.lastname: Zdunek
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D004566:Electrodes; D005583:Fourier Analysis; D006368:Helianthus / Q000187:drug effects / Q000502:physiology*; D007473:Ion Channels / Q000378:metabolism*; D049990:Membrane Transport Modulators / Q000494:pharmacology; D009068:Movement; D018547:Plant Stems / Q000187:drug effects / Q000502:physiology*; D054328:Proton Pump Inhibitors / Q000378:metabolism*; D012996:Solutions
chemical_list: D007473:Ion Channels; D049990:Membrane Transport Modulators; D054328:Proton Pump Inhibitors; D012996:Solutions