title: Physiological effects of arsenic in the lichen Xanthoria parietina (L.) Th. Fr.
abstract: The aim of this study was to test in a short term laboratory experiment the accumulation and physiological effects of As in the epiphytic lichen Xanthoria parietina. Arsenic content in treated samples increased progressively with increasing concentration in treatment solutions. Treatment of X. parietina thalli with 0.1, 1, 10 ppm As solutions caused significant decrease of viability, measured as intensity of respiratory activity, and damages to cell membranes, assessed by increase of electric conductivity of rinsing water and lipid peroxidation products. Soluble proteins content decreased and H₂O₂ content increased already at the lowest As concentration tested (0.01 ppm). Photosynthetic efficiency, measured in terms of F(V)/F(M) ratio, decreased significantly only at the highest As concentration (10 ppm). It was concluded that As exposure causes physiological stress both on the mycobiont and the photobiont and that cell membrane damage, expressed in terms of electric conductivity of rinsing water, is the parameter most affected by As treatment.
authors.affiliation: Department of Environmental Science "G. Sarfatti", University of Siena, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Pisani
authors.forename: Silvana
authors.initials: S
authors.lastname: Munzi
authors.forename: Luca
authors.initials: L
authors.lastname: Paoli
authors.forename: Martin
authors.initials: M
authors.lastname: Bačkor
authors.forename: Stefano
authors.initials: S
authors.lastname: Loppi
mesh_terms: D001149:Arsenates / Q000633:toxicity; D001151:Arsenic / Q000378:metabolism / Q000633:toxicity*; D001203:Ascomycota / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D002462:Cell Membrane / Q000187:drug effects; D002734:Chlorophyll / Q000378:metabolism; D004785:Environmental Pollutants / Q000378:metabolism / Q000633:toxicity*; D008011:Lichens / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D015227:Lipid Peroxidation / Q000187:drug effects; D010788:Photosynthesis / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D001149:Arsenates; D004785:Environmental Pollutants; D017382:Reactive Oxygen Species; D002734:Chlorophyll; D001151:Arsenic; C025657:arsenic acid