title: Lead effects on Brassica napus photosynthetic organs.
abstract: In this study, effects of lead on ultracellular structure and pigment contents of Brassica napus were examined. Pb(II) was added in soluble form to soil prior to sowing. Pb contents were measured in plant organs at the ontogenetic stages of flowering (FL) and physiological maturity (PM). Pigment contents were evaluated through reflectance measurements. Pb content in organs was found to decrease in the order; roots>stems>leaves. Lead content in senescent leaves at FL stage was significantly higher than harvested leaves, strongly suggesting a detoxification mechanism. Leaves and stems harvested at the PM stage showed damage at subcellular level, namely chloroplast disorganization, cell wall damage and presence of osmiophilic bodies. Chlorophyll content increased in the presence of Pb at the FL stage, compared with control; at the PM stage, chlorophyll contents decreased with low Pb concentration but showed no significant differences with control at high Pb soil concentration. The results suggest an increase in antioxidants at low Pb concentration and cell damage at higher lead concentration.
authors.affiliation: Instituto de Química Física de Materiales, Ambiente y Energía, CONICET and Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Gisele V
authors.initials: GV
authors.lastname: Ferreyroa
authors.affiliation: Instituto de Química Física de Materiales, Ambiente y Energía, CONICET and Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: M Gabriela
authors.initials: MG
authors.lastname: Lagorio
authors.affiliation: Instituto de Geociencias Básicas y Aplicadas de Buenos Aires, CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: María A
authors.initials: MA
authors.lastname: Trinelli
authors.affiliation: Instituto de Investigaciones en Biociencias Agrícolas y Ambientales, CONICET, Facultad de Agronomía, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Raúl S
authors.initials: RS
authors.lastname: Lavado
authors.affiliation: Instituto de Química Física de Materiales, Ambiente y Energía, CONICET and Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina. Electronic address: fmolina@qi.fcen.uba.ar.
authors.forename: Fernando V
authors.initials: FV
authors.lastname: Molina
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D001118:Argentina; D018533:Biomass; D029688:Brassica napus / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D002734:Chlorophyll / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism; D004784:Environmental Monitoring; D007854:Lead / Q000032:analysis / Q000633:toxicity*; D010788:Photosynthesis / Q000187:drug effects*; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D018547:Plant Stems / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis / Q000633:toxicity*
chemical_list: D000975:Antioxidants; D012987:Soil; D012989:Soil Pollutants; D002734:Chlorophyll; D007854:Lead
keywords: Cell damage; Heavy metals; Photosynthetic pigments; Soil pollution