title: Subcellular Sequestration and Impact of Heavy Metals on the Ultrastructure and Physiology of the Multicellular Freshwater Alga Desmidium swartzii.
abstract: Due to modern life with increasing traffic, industrial production and agricultural practices, high amounts of heavy metals enter ecosystems and pollute soil and water. As a result, metals can be accumulated in plants and particularly in algae inhabiting peat bogs of low pH and high air humidity. In the present study, we investigated the impact and intracellular targets of aluminum, copper, cadmium, chromium VI and zinc on the filamentous green alga Desmidium swartzii, which is an important biomass producer in acid peat bogs. By means of transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) it is shown that all metals examined are taken up into Desmidium readily, where they are sequestered in cell walls and/or intracellular compartments. They cause effects on cell ultrastructure to different degrees and additionally disturb photosynthetic activity and biomass production. Our study shows a clear correlation between toxicity of a metal and the ability of the algae to compartmentalize it intracellularly. Cadmium and chromium, which are not compartmentalized, exert the most toxic effects. In addition, this study shows that the filamentous alga Desmidium reacts more sensitively to aluminum and zinc when compared to its unicellular relative Micrasterias, indicating a severe threat to the ecosystem.
authors.affiliation: Plant Physiology Division, Cell Biology Department, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria. ancuela.andosch@sbg.ac.at.
authors.forename: Ancuela
authors.initials: A
authors.lastname: Andosch
authors.affiliation: Plant Physiology Division, Cell Biology Department, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria. margit.hoeftberger@sbg.ac.at.
authors.forename: Margit
authors.initials: M
authors.lastname: Höftberger
authors.affiliation: Institute of Botany, Faculty of Biology, University of Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria. cornelius.luetz@uibk.ac.at.
authors.forename: Cornelius
authors.initials: C
authors.lastname: Lütz
authors.affiliation: Plant Physiology Division, Cell Biology Department, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria. ursula.meindl@sbg.ac.at.
authors.forename: Ursula
authors.initials: U
authors.lastname: Lütz-Meindl
mesh_terms: D002451:Cell Compartmentation; D002473:Cell Wall / Q000187:drug effects; D058114:Desmidiales / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D019216:Metals, Heavy / Q000633:toxicity*; D010788:Photosynthesis
chemical_list: D019216:Metals, Heavy