title: Effects of heavy metals on ultrastructure and HSP70s induction in the aquatic moss Leptodictyum riparium Hedw.
abstract: The effects of heavy metals, both toxic (Pb, Cd) and essential (Cu, Zn) on the ultrastructure and the induction of Heat Shock Protein 70 (HSP70) have been studied in the aquatic moss Leptodictyum riparium Hedw. In vitro cultured L. riparium was treated with different heavy metals, both toxic, as cadmium or lead; and essential microelements such as Copper or Zinc concentrations ranging from 10(-3) to 10(-6) M to investigate both ultrastructural damage and HSP induction. TEM observations showed that sub-lethal concentrations of heavy metals caused only slight changes, largely localized in the chloroplasts. Among all the heavy metals tested, cadmium caused the most severe modifications. Heavy metals caused the decrease of the soluble protein content and the enhancement of proteins reacting versus HSP70 antibodies, suggesting that molecular chaperons might be involved in the resistance to toxic effects of lead, cadmium, copper and zinc. Therefore, the induction of HSP70 in L. riparium would confer a higher resistance to pollutants under stressful conditions lethal for other mosses and higher plant species. These results suggest that the moss L. riparium can tolerate heavy metals stress without incurring severe cellular/subcellular damage. Therefore it can be used as a useful indicator of heavy metals accumulation.
authors.affiliation: Dipartimento di Biologia Strutturale e Funzionale - Università di Napoli "Federico II" - Naples, Italy. sergio.esposito@unina.it
authors.forename: S
authors.initials: S
authors.lastname: Esposito
authors.forename: S
authors.initials: S
authors.lastname: Sorbo
authors.forename: B
authors.initials: B
authors.lastname: Conte
authors.forename: A
authors.initials: A
authors.lastname: Basile
mesh_terms: D019068:Bryopsida / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure*; D002104:Cadmium / Q000378:metabolism / Q000633:toxicity; D003300:Copper / Q000378:metabolism / Q000633:toxicity; D004577:Electron Probe Microanalysis; D004785:Environmental Pollutants / Q000378:metabolism / Q000633:toxicity*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D007854:Lead / Q000378:metabolism / Q000633:toxicity; D019216:Metals, Heavy / Q000378:metabolism / Q000633:toxicity*; D046529:Microscopy, Electron, Transmission; D015032:Zinc / Q000378:metabolism / Q000633:toxicity
chemical_list: D004785:Environmental Pollutants; D018840:HSP70 Heat-Shock Proteins; D019216:Metals, Heavy; D002104:Cadmium; D007854:Lead; D003300:Copper; D015032:Zinc