title: Auxin effects on ion transport in Chara corallina.
abstract: The plant hormone auxin has been widely studied with regard to synthesis, transport, signaling and functions among the land plants while there is still a lack of knowledge about the possible role for auxin regulation mechanisms in algae with "plant-like" structures. Here we use the alga Chara corallina as a model to study aspects of auxin signaling. In this respect we measured auxin on membrane potential changes and different ion fluxes (K(+), H(+)) through the plasma membrane. Results showed that auxin, mainly IAA, could hyperpolarize the membrane potential of C. corallina internodal cells. Ion flux measurements showed that the auxin-induced membrane potential change may be based on the change of K(+) permeability and/or channel activity rather than through the activation of proton pumps as known in land plants.
authors.affiliation: Plant Biodynamics Laboratory, Institute Biology Leiden, Leiden University, Sylvius Laboratory, Sylviusweg 72, 2333 BE Leiden, The Netherlands.
authors.forename: Suyun
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Structural Biology, Faculty Earth and Life Sciences, Vrije Universiteit, De Boelelaan 1085-1087, 1081HV Amsterdam, The Netherlands.
authors.forename: Albertus H
authors.initials: AH
authors.lastname: de Boer
authors.affiliation: Plant Biodynamics Laboratory, Institute Biology Leiden, Leiden University, Sylvius Laboratory, Sylviusweg 72, 2333 BE Leiden, The Netherlands; Fytagoras, Sylvius Laboratory, Sylviusweg 72, 2333 BE Leiden, The Netherlands. Electronic address: bert.vanduijn@fytagoras.com.
authors.forename: Bert
authors.initials: B
authors.lastname: van Duijn
mesh_terms: D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D044784:Chara / Q000187:drug effects / Q000502:physiology*; D007210:Indoleacetic Acids / Q000494:pharmacology*; D017136:Ion Transport; D008564:Membrane Potentials / Q000187:drug effects; D010937:Plant Growth Regulators / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D011188:Potassium
keywords: Chara corallina; H(+)-ATPase; IAA; Membrane potential; Potassium transport