title: Effect of inhibitors of auxin transport and of calmodulin on a gravisensing-dependent current in maize roots.
abstract: Some characteristics of the gravity sensing mechanism in maize root caps were investigated using a bioelectric current as an indicator of gravity sensing.  This technique involves the measurement of a change in the current density which arises at the columella region coincidently with the presentation time.  Two inhibitors of auxin transport, triiodobenzoic acid and naphthylphthalamic acid, blocked gravitropic curvature but not the change in current density.  Two inhibitors of calmodulin activity, compound 48/80 and calmidazolium, blocked both curvature and gravity-induced current.  The results suggest that auxin transport is not a component of gravity sensing in the root cap.  By contrast, the results suggest that calmodulin plays an intrinsic role in gravity sensing.
authors.affiliation: Boyce Thompson Institute, Cornell University, Ithaca, New York 14853-1801, USA.
authors.forename: T
authors.initials: T
authors.lastname: Björkman
authors.forename: A C
authors.initials: AC
authors.lastname: Leopold
mesh_terms: D001692:Biological Transport / Q000187:drug effects; D002147:Calmodulin / Q000037:antagonists & inhibitors* / Q000502:physiology; D004560:Electricity; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018522:Gravitropism / Q000187:drug effects* / Q000502:physiology; D018466:Gravity Sensing / Q000187:drug effects / Q000502:physiology*; D006540:Herbicides / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D007210:Indoleacetic Acids / Q000037:antagonists & inhibitors / Q000493:pharmacokinetics* / Q000502:physiology; D010797:Phthalimides / Q000494:pharmacology; D010937:Plant Growth Regulators / Q000494:pharmacology; D018518:Plant Root Cap / Q000187:drug effects / Q000254:growth & development / Q000502:physiology; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D014283:Triiodobenzoic Acids / Q000494:pharmacology; D003313:Zea mays / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology
chemical_list: D002147:Calmodulin; D004791:Enzyme Inhibitors; D006540:Herbicides; D007093:Imidazoles; D007210:Indoleacetic Acids; D010797:Phthalimides; D010937:Plant Growth Regulators; D014283:Triiodobenzoic Acids; C002687:alpha-naphthylphthalamic acid; D003189:p-Methoxy-N-methylphenethylamine; C031938:calmidazolium