title: Reproduction of aquatic hyphomycetes at low concentrations of Ca2+, Zn2+, Cu2+, and Cd2+.
abstract: Maple leaf disks were conditioned in a stream for three weeks and then aerated for 2 d in distilled water to induce fungal sporulation. The release of aquatic hyphomycete spores increased when the water was supplemented with low concentrations of Ca(2+) (5 µg/L), Zn(2+) (2.5 µg/L), Cu(2+) (0.5 µg/L), or Cd(2+) (0.125 µg/L). Higher supplement concentrations inhibited sporulation. Over the concentration range used, the sporulation response was generally best described by a quadratic regression, suggesting a biphasic or hormetic response. A similar pattern was found with the number of fungal species as the dependent variable. Anguillospora filiformis and Anguillospora longissima were generally least inhibited by metal supplements, and Ca(2+) was the least and Cd(2+) the most toxic metal. Combinations of metals had a more severe effect on fungal sporulation than predicted from addition of the effects of the metals in isolation. The biological significance of the hormetic response is unclear; however, acknowledging it is clearly relevant for establishing guidelines or recommendations in toxicology.
authors.affiliation: Department of Biosciences, Mangalore University, Mangalagangotri, Karnataka, India.
authors.forename: Kandikere R
authors.initials: KR
authors.lastname: Sridhar
authors.forename: Felix
authors.initials: F
authors.lastname: Bärlocher
mesh_terms: D002104:Cadmium / Q000633:toxicity; D002118:Calcium / Q000633:toxicity; D002413:Cations, Divalent / Q000633:toxicity; D003300:Copper / Q000633:toxicity; D008670:Metals / Q000633:toxicity*; D003904:Mitosporic Fungi / Q000187:drug effects* / Q000254:growth & development; D045483:Rivers / Q000737:chemistry / Q000382:microbiology*; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015032:Zinc / Q000633:toxicity
chemical_list: D002413:Cations, Divalent; D008670:Metals; D014874:Water Pollutants, Chemical; D002104:Cadmium; D003300:Copper; D015032:Zinc; D002118:Calcium