title: Copper tolerance in the macrolichens Cladonia furcata and Cladina arbuscula subsp. mitis is constitutive rather than inducible.
abstract: In this study we assessed the degree of copper (Cu) tolerance in two common lichen species (Cladonia furcata and Cladina arbuscula subsp. mitis) that grow on both uncontaminated substrata and the surface of waste heaps from abandoned old Cu-mines. Regardless of their locality, populations of these lichens contain identical strains of photobionts (Asterochloris clade A in C. arbuscula subsp. mitis and clade D in C. furcata). Therefore, it was expected that if there were differences in Cu toxicity or tolerance between populations, that the photobiont could not be a key element of Cu tolerance in these two lichen species. In laboratory experiments samples of both lichen species (from contaminated and control sites) were incubated in Cu solutions (500 μM) for 24 h. We attempted to determine whether Cu tolerance in these lichens was constitutive, or inducible form. Based on measurements of Cu accumulation, chlorophyll a integrity, chlorophyll a fluorescence, photosynthesis, respiration, measurements of the content of thiobarbituric acid reactive substances (TBARS), the content of soluble proteins, reactive oxygen species (ROS) and the amount of extracellular secondary metabolites of both lichens we found that there were no significant differences in the response of all selected populations of both lichen species to short-term exposure to these high levels of Cu. As a result, we conclude that Cu tolerance in these two lichen species is the constitutive rather than the inducible.
authors.affiliation: Department of Botany, Institute of Biology and Ecology, Faculty of Science, Šafárik University, Mánesova 23, 041 67 Košice, Slovak Republic. martin.backor@upjs.sk
authors.forename: Martin
authors.initials: M
authors.lastname: Bačkor
authors.forename: Evelin Ramóna
authors.initials: ER
authors.lastname: Péli
authors.forename: Ivana
authors.initials: I
authors.lastname: Vantová
mesh_terms: D002245:Carbon Dioxide / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D003300:Copper / Q000378:metabolism* / Q000633:toxicity; D008011:Lichens / Q000378:metabolism*; D010788:Photosynthesis; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D017382:Reactive Oxygen Species; D002734:Chlorophyll; D002245:Carbon Dioxide; D003300:Copper; D000077194:Chlorophyll A