title: Transient alkalinization in the leaf apoplast of Vicia faba L. depends on NaCl stress intensity: an in situ ratio imaging study.
abstract: The apoplast is suggested to be involved not only in the response, but also in the perception and transduction of various environmental signals. In this context, apoplastic alkalinization has previously been discussed as a general stress factor caused by abiotic and biotic stress events. In this study, an ion-sensitive fluorescence probe in combination with inverted fluorescence microscopy has been used for in planta monitoring of apoplastic shoot pH during challenging of Vicia faba L. plants by NaCl stress encountered at the roots. We demonstrate that transient increases in leaf apoplastic pH are dependent on the NaCl stress intensity. Moreover, we have visualized spatial pH gradients within the leaf apoplast. Our results indicate that these pH responses are propagated from root to leaf and that this occurs along the apoplast.
authors.affiliation: Institute of Plant Nutrition and Soil Science, Christian Albrechts University, Hermann-Rodewald-Strasse 2, Kiel, Germany.
authors.forename: Christoph-Martin
authors.initials: CM
authors.lastname: Geilfus
authors.forename: Karl Hermann
authors.initials: KH
authors.lastname: Mühling
mesh_terms: D006863:Hydrogen-Ion Concentration; D018613:Microscopy, Confocal; D018515:Plant Leaves / Q000502:physiology*; D018517:Plant Roots / Q000187:drug effects / Q000502:physiology; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological; D031307:Vicia faba / Q000502:physiology*
chemical_list: D012965:Sodium Chloride