title: The physiological mechanisms underlying the ability of Cistus monspeliensis L. from São Domingos mine to withstand high Zn concentrations in soils.
abstract: Cistus monspeliensis L. is a species that grows spontaneously in contaminated mining areas from the Iberian Pyrite Belt. This species can have high concentrations of Zn in the shoots without visible signs of phytotoxicity. In order to understand the physiological mechanisms underlying this tolerance, C. monspeliensis was grown at several concentrations of Zn(2+) (0, 500, 1000, 1500, 2000µM) and the effects of this metal on plant development and on the defence mechanisms against oxidative stress were evaluated. Independently of the treatment, Zn was mainly retained in the roots. The plants with the highest concentrations of Zn showed toxicity symptoms such as chlorosis, low leaf size and decrease in biomass production. At 2000µM of Zn, the dry biomass of the shoots decreased significantly. High concentrations of Zn in shoots did not induce deficiencies of other nutrients, except Cu. Plants with high concentrations of Zn had low amounts of chlorophyll, anthocyanins and glutathione and high contents of H2O2. The highest concentrations of Zn in shoots of C. monspeliensis triggered defence mechanisms against oxidative stress, namely by triggering antioxidative enzyme activity and by direct reactive oxygen species (ROS) scavenging through carotenoids, that are unaffected by stress due to stabilisation by ascorbic acid.
authors.affiliation: Universidad de Vigo, Department of Plant Biology and Soil Science, Vigo, Spain. Electronic address: darenas@uvigo.es.
authors.forename: Daniel
authors.initials: D
authors.lastname: Arenas-Lago
authors.affiliation: Linking Landscape, Environment, Agriculture and Food Research Centre (LEAF), Instituto Superior de Agronomia, Universidade de Lisboa, Lisboa, Portugal.
authors.forename: Luísa C
authors.initials: LC
authors.lastname: Carvalho
authors.affiliation: Linking Landscape, Environment, Agriculture and Food Research Centre (LEAF), Instituto Superior de Agronomia, Universidade de Lisboa, Lisboa, Portugal; Centro de Investigação em Ciências do Ambiente e Empresariais, Instituto Superior Dom Afonso III, Loulé, Portugal.
authors.forename: Erika S
authors.initials: ES
authors.lastname: Santos
authors.affiliation: Linking Landscape, Environment, Agriculture and Food Research Centre (LEAF), Instituto Superior de Agronomia, Universidade de Lisboa, Lisboa, Portugal.
authors.forename: M Manuela
authors.initials: MM
authors.lastname: Abreu
mesh_terms: D000872:Anthocyanins / Q000032:analysis; D001205:Ascorbic Acid / Q000032:analysis; D002338:Carotenoids / Q000032:analysis; D002734:Chlorophyll / Q000032:analysis; D029758:Cistus / Q000187:drug effects* / Q000254:growth & development*; D005978:Glutathione / Q000032:analysis; D006861:Hydrogen Peroxide / Q000032:analysis; D018384:Oxidative Stress / Q000187:drug effects; D063245:Plant Development / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D017382:Reactive Oxygen Species / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D015032:Zinc / Q000032:analysis* / Q000633:toxicity
chemical_list: D000872:Anthocyanins; D017382:Reactive Oxygen Species; D012987:Soil; D012989:Soil Pollutants; D002734:Chlorophyll; D002338:Carotenoids; D006861:Hydrogen Peroxide; D005978:Glutathione; D015032:Zinc; D001205:Ascorbic Acid
keywords: Ascorbate; Ascorbate–glutathione cycle; Carotenoids; Glutathione; Oxidative stress; Reactive oxygen species