title: Fluorescence recovery after photobleaching reveals high cycling dynamics of plasma membrane aquaporins in Arabidopsis roots under salt stress.
abstract: The constitutive cycling of plant plasma membrane (PM) proteins is an essential component of their function and regulation under resting or stress conditions. Transgenic Arabidopsis plants that express GFP fusions with AtPIP1;2 and AtPIP2;1, two prototypic PM aquaporins, were used to develop a fluorescence recovery after photobleaching (FRAP) approach. This technique was used to discriminate between PM and endosomal pools of the aquaporin constructs, and to estimate their cycling between intracellular compartments and the cell surface. The membrane trafficking inhibitors tyrphostin A23, naphthalene-1-acetic acid and brefeldin A blocked the latter process. By contrast, a salt treatment (100 mm NaCl for 30 min) markedly enhanced the cycling of the aquaporin constructs and modified their pharmacological inhibition profile. Two distinct models for PM aquaporin cycling in resting or salt-stressed root cells are discussed.
authors: Biochimie et Physiologie Moléculaire des Plantes, Institut de Biologie Intégrative des Plantes, UMR 5004 CNRS/UMR 0386 INRA/Montpellier SupAgro/Université Montpellier 2, Montpellier Cedex 2, France. luu@supagro.inra.fr
authors: Doan-Trung
authors: DT
authors: Luu
authors: Alexandre
authors: A
authors: Martinière
authors: Mathias
authors: M
authors: Sorieul
authors: John
authors: J
authors: Runions
authors: Christophe
authors: C
authors: Maurel
mesh_terms: D020346:Aquaporins / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D020126:Brefeldin A; D036681:Fluorescence Recovery After Photobleaching; D018506:Gene Expression Regulation, Plant; D009280:Naphthaleneacetic Acids; D018517:Plant Roots / Q000502:physiology*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000502:physiology; D021381:Protein Transport; D012965:Sodium Chloride / Q000494:pharmacology*; D020032:Tyrphostins
chemical_list: D020346:Aquaporins; D029681:Arabidopsis Proteins; D009280:Naphthaleneacetic Acids; D020032:Tyrphostins; C491680:plasma membrane intrinsic protein 2 Arabidopsis; D020126:Brefeldin A; D012965:Sodium Chloride; C060641:tyrphostin A23