title: Physiological responses of root-less epiphytic plants to acid rain.
abstract: Selected physiological responses of Tillandsia albida (Bromeliaceae) and two lichens (Hypogymnia physodes and Xanthoria parietina) exposed to simulated acid rain (AR) over 3 months were studied. Pigments were depressed in all species being affected the most in Tillandsia. Amounts of hydrogen peroxide and superoxide were elevated and soluble proteins decreased only in AR-exposed Hypogymnia. Free amino acids were slightly affected among species and only glutamate sharply decreased in AR-exposed Xanthoria. Slight increase in soluble phenols but decrease in flavonoids in almost all species suggests that the latter are not essential for tolerance to AR. Almost all phenolic acids in Tillandsia leaves decreased in response to AR and activities of selected enzymes (phenylalanine ammonia-lyase, polyphenol oxidase, ascorbate- and guaiacol-peroxidase) were enhanced by AR. In lichens, considerable increase in metabolites (physodalic acid, atranorin and parietin) in response to AR was found but amount of ergosterol was unchanged. Macronutrients (K, Ca, Mg) decreased more pronouncedly in comparison with micronutrients in all species. Xanthoria showed higher tolerance in comparison with Hypogymnia, suggesting that could be useful for long-term biomonitoring.
authors.affiliation: Faculty of Science, Department of Botany, P J Šafárik University, Košice, Slovak Republic. jozkovacik@yahoo.com
authors.forename: Jozef
authors.initials: J
authors.lastname: Kováčik
authors.forename: Bořivoj
authors.initials: B
authors.lastname: Klejdus
authors.forename: Martin
authors.initials: M
authors.lastname: Bačkor
authors.forename: František
authors.initials: F
authors.lastname: Stork
authors.forename: Josef
authors.initials: J
authors.lastname: Hedbavny
mesh_terms: D015258:Acid Rain; D000596:Amino Acids / Q000378:metabolism; D060387:Ascorbate Peroxidases; D031229:Bromeliaceae / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D004156:Catechol Oxidase / Q000378:metabolism; D008011:Lichens / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D008903:Minerals / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D010544:Peroxidases / Q000378:metabolism; D010636:Phenols / Q000378:metabolism; D010650:Phenylalanine Ammonia-Lyase / Q000378:metabolism; D010860:Pigments, Biological / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D015258:Acid Rain; D000596:Amino Acids; D008903:Minerals; D010636:Phenols; D010860:Pigments, Biological; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D004156:Catechol Oxidase; D010544:Peroxidases; C121048:guaiacol peroxidase; D060387:Ascorbate Peroxidases; D009195:Peroxidase; D010650:Phenylalanine Ammonia-Lyase