title: Compartment specific response of antioxidants to drought stress in Arabidopsis.
abstract: Compartment specific changes in ascorbate and glutathione contents were studied during drought stress in Arabidopsis thaliana Col-0 and in ascorbate and glutathione deficient mutants vtc2-1 and pad2-1, respectively, over a time period of 10 days. The results of this study revealed a strong decrease of glutathione contents in both mutants (up to 52% in mitochondria of pad2-1 and 40% in nuclei of vtc2-1) at early time points when drought stress was not yet measurable in leaves even though the soil showed a drop in relative water contents. These results indicate that glutathione is used at early time points to signal drought stress from roots to leaves. Such roles could not be confirmed for ascorbate which remained unchanged in most cell compartments until very late stages of drought. During advanced drought stress the strong depletion of ascorbate and glutathione in chloroplasts (up to 50% in Col-0 and vtc2-1) and peroxisomes (up to 56% in Col-0) could be correlated with a strong accumulation of H2O2. The strong increase of H2O2 and ascorbate in vacuoles (up to 111%) in wildtype plants indicates that ascorbate plays an important role for the detoxification of ROS in vacuoles during drought stress.
authors.affiliation: University of Graz, Institute of Plant Sciences, Schubertstrasse 51, 8010 Graz, Austria.
authors.forename: Barbara Eva
authors.initials: BE
authors.lastname: Koffler
authors.affiliation: University of Graz, Institute of Plant Sciences, Schubertstrasse 51, 8010 Graz, Austria.
authors.forename: Nora
authors.initials: N
authors.lastname: Luschin-Ebengreuth
authors.affiliation: University of Graz, Institute of Plant Sciences, Schubertstrasse 51, 8010 Graz, Austria.
authors.forename: Edith
authors.initials: E
authors.lastname: Stabentheiner
authors.affiliation: University of Graz, Institute of Plant Sciences, Schubertstrasse 51, 8010 Graz, Austria.
authors.forename: Maria
authors.initials: M
authors.lastname: Müller
authors.affiliation: Baylor University, Center for Microscopy and Imaging, One Bear Place #97046, Waco, TX 76798, USA. Electronic address: Bernd_Zechmann@baylor.edu.
authors.forename: Bernd
authors.initials: B
authors.lastname: Zechmann
mesh_terms: D000222:Adaptation, Physiological; D000975:Antioxidants / Q000378:metabolism*; D017360:Arabidopsis / Q000378:metabolism*; D001205:Ascorbic Acid / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism; D055864:Droughts; D005978:Glutathione / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D009154:Mutation; D015388:Organelles / Q000378:metabolism*; D020675:Peroxisomes / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D012987:Soil; D013312:Stress, Physiological; D014617:Vacuoles / Q000378:metabolism; D014867:Water
chemical_list: D000975:Antioxidants; D012987:Soil; D014867:Water; D006861:Hydrogen Peroxide; D005978:Glutathione; D001205:Ascorbic Acid
keywords: Arabidopsis; Ascorbate; Glutathione; Reactive oxygen species; Vacuoles