title: Growth and physiological responses to cadmium stress of two populations of Dittrichia viscosa (L.) Greuter.
abstract: Two clones of Dittrichia viscosa (L.) Greuter from contrasting populations, DV-A (metallicolous) and DV-W (non-metallicolous), were studied to compare Cd accumulation and tolerance. After 10 days of hydroponic culture with 0, 5, 10, and 15 mg Cd L(-1), metal accumulation and plant growth were measured as well as other stress markers such as decrease in the content of photosynthetic pigments, lipid peroxidation, phenols, H(2)O(2), and free proline. We also analyzed the activity of the antioxidant enzymes guaiacol and ascorbate peroxidases, catalase, superoxide dismutase, and glutathione reductase as well as their isoform patterns. Our results confirmed a high Cd tolerance and accumulation in both clones of D. viscosa, which suggests that these traits are constitutive in this species. However, when the Cd concentration in solution exceeded 10 mg Cd L(-1), DV-A was more tolerant than DV-W. The physiological mechanisms involved in Cd tolerance also differed between them, although phenols and guaiacol peroxidase played an important role in both clones. The effective Cd detoxification of DV-A consisted mainly in a promoted ascorbate peroxidase activity and better efficiency of catalase and glutathione reductase enzymes.
authors.affiliation: Departamento de Biología de Organismos y Sistemas, Universidad de Oviedo, Catedrático Rodrigo Uría s/n, 33071 Oviedo, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Fernández
authors.forename: A
authors.initials: A
authors.lastname: Bertrand
authors.forename: R
authors.initials: R
authors.lastname: Reis
authors.forename: M P
authors.initials: MP
authors.lastname: Mourato
authors.forename: L L
authors.initials: LL
authors.lastname: Martins
authors.forename: A
authors.initials: A
authors.lastname: González
mesh_terms: D060387:Ascorbate Peroxidases / Q000378:metabolism; D019659:Asteraceae / Q000187:drug effects* / Q000502:physiology; D002104:Cadmium / Q000378:metabolism / Q000633:toxicity*; D002338:Carotenoids / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D010636:Phenols / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000502:physiology; D018517:Plant Roots / Q000187:drug effects / Q000502:physiology; D018520:Plant Shoots / Q000187:drug effects / Q000502:physiology; D011392:Proline / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*
chemical_list: D010636:Phenols; D014874:Water Pollutants, Chemical; D002104:Cadmium; D002734:Chlorophyll; D002338:Carotenoids; D011392:Proline; D006861:Hydrogen Peroxide; D060387:Ascorbate Peroxidases; D002374:Catalase; D005980:Glutathione Reductase