title: Evaluation of mercury stress in plants from the Almadén mining district by analysis of phytochelatins and their Hg complexes.
abstract: To evaluate plant response to Hg stress, glutathione, phytochelatins, and their Hg complexes were analyzed using HPLC with amperometric detection in samples of Asparagus acutifolius grown in the Almadén mining district (Ciudad Real, Spain), one of the most Hg-contaminated sites in the world. Soils of the Almadén mining district, and specifically from the Almadenejos zone, are highly contaminated, with some zones having values above 4,000 μg Hg g(-1) soil. Although soils have an extremely high concentration of mercury, generally less than 2% is available for plants, as is shown by various soil extractions simulating bioavailability. In plants, Hg concentration increases depending on the content of Hg in soils. In addition, Hg levels in roots are higher than in aerial parts, which is a strategy of plants for protecting their more sensitive aerial parts from the deleterious effects of metal stress. The total content of phytochelatins (PCs) and their complexes are directly related with the amount of mercury in soils. These findings highlight the important role of thiol compounds and their metal complexes in capturing and fixing Hg from soils, giving plants the capacity to deal with the heavy metal toxicity of polluted soils.
authors.affiliation: Departament de Química Analítica, Facultat de Química, Universitat de Barcelona , Martí i Franquès, 1-11, 08028 Barcelona, Barcelona, Spain.
authors.forename: Àngela
authors.initials: À
authors.lastname: Dago
authors.forename: Inmaculada
authors.initials: I
authors.lastname: González
authors.forename: Cristina
authors.initials: C
authors.lastname: Ariño
authors.forename: Alba
authors.initials: A
authors.lastname: Martínez-Coronado
authors.forename: Pablo
authors.initials: P
authors.lastname: Higueras
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Díaz-Cruz
authors.forename: Miquel
authors.initials: M
authors.lastname: Esteban
mesh_terms: D027761:Asparagus Plant / Q000737:chemistry / Q000187:drug effects* / Q000502:physiology; D005978:Glutathione / Q000032:analysis / Q000737:chemistry*; D008628:Mercury / Q000032:analysis / Q000633:toxicity*; D008906:Mining; D054811:Phytochelatins / Q000737:chemistry*; D035261:Plant Components, Aerial / Q000737:chemistry / Q000187:drug effects; D018517:Plant Roots / Q000737:chemistry / Q000187:drug effects; D012989:Soil Pollutants / Q000032:analysis / Q000633:toxicity*; D013030:Spain; D013312:Stress, Physiological / Q000187:drug effects* / Q000502:physiology
chemical_list: D012989:Soil Pollutants; D054811:Phytochelatins; D008628:Mercury; D005978:Glutathione