title: Response of two terrestrial green microalgae (Chlorophyta, Trebouxiophyceae) isolated from Cu-rich and unpolluted soils to copper stress.
abstract: Some algae inhabit Cu-polluted soils. Intracellular Cu-accumulation and production of non-protein thiols in response to copper stress were compared in Stichococcus minor and Geminella terricola isolated from Cu-polluted and unpolluted soils, respectively. Cu-exposed (0.5 microM) S. minor accumulated lower amounts of copper (0.38 mM) than G. terricola (4.20 mM) and maintained 8.5-fold higher level of glutathione (GSH) than G. terricola. The ratio GSH/0.5 GSSG in the Cu-treated S. minor (7.21) was 7-times higher than in G. terricola. Reduced and oxidized forms of phytochelatins were found in both algae. Under copper stress (5 microM) the ratio -SH(total)/Cu(intracellular) in S. minor ranged from 2.3 to 6.2, while it was lower than 1.0 in G. terricola. Low intracellular Cu-accumulation and maintenance of high GSH level concomitant with PCs production seem to be responsible for a higher Cu-resistance of S. minor than G. terricola.
authors.affiliation: Centre for Ecological Research, Polish Academy of Sciences, Experimental Station, Niecała18/3, 20-080 Lublin, Poland. renata_kalinowska@tlen.pl
authors.forename: Renata
authors.initials: R
authors.lastname: Kalinowska
authors.forename: Barbara
authors.initials: B
authors.lastname: Pawlik-Skowrońska
mesh_terms: D000460:Chlorophyta / Q000187:drug effects* / Q000302:isolation & purification / Q000378:metabolism; D003300:Copper / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D003545:Cysteine / Q000378:metabolism; D004151:Dipeptides / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D054811:Phytochelatins / Q000378:metabolism; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*
chemical_list: D004151:Dipeptides; D012989:Soil Pollutants; D003300:Copper; D054811:Phytochelatins; D005978:Glutathione; D003545:Cysteine; C017341:gamma-glutamylcysteine