title: Membrane-directed effects of the plant hormones abscisic acid, indole-3-acetic acid and 2,4-dichlorophenoxyacetic acid.
abstract: This study examines two ways plant hormones might influence membrane processes, effects on overall permeability and modifications of specific ion channels. Abscisic acid (ABA) and indole-3-acetic acid (IAA) greatly enhanced erythritol permeability in mixed egg lecithin bilayers. In single component dioleoylphosphatidylcholine bilayers ABA was less effective than IAA, while 2,4-dichlorophenoxyacetate (2,4-D) did not affect either system or alter their ABA response. In Myxicola axons ABA and IAA had no effect, while 2,4-D (10 uM) caused a depolarizing shift of voltage-dependent Na+ and K+ activation by 25 +/- 4 mV and 15 +/- 3 mV, consistent with internal negative surface charge changes of -0.002 e-/A2 and -0.0007 e-/A2. We conclude that both generalized and ion channel-directed effects may link plant hormones and intracellular regulation.
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000494:pharmacology; D000040:Abscisic Acid / Q000494:pharmacology; D000818:Animals; D001369:Axons / Q000187:drug effects / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000187:drug effects*; D007210:Indoleacetic Acids / Q000494:pharmacology; D007473:Ion Channels / Q000187:drug effects* / Q000378:metabolism; D008051:Lipid Bilayers; D010937:Plant Growth Regulators / Q000494:pharmacology*; D011077:Polychaeta; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism
chemical_list: D007210:Indoleacetic Acids; D007473:Ion Channels; D008051:Lipid Bilayers; D010937:Plant Growth Regulators; D015084:2,4-Dichlorophenoxyacetic Acid; C030737:indoleacetic acid; D000040:Abscisic Acid; D012964:Sodium; D011188:Potassium