title: Applications in environmental bioinorganic: Nutritional and ultrastructural evaluation and calculus of thermodynamic and structural properties of metal-oxalate complexes.
abstract: Lead (Pb) is known by its toxicity both for animals and plants. In order to evaluate its toxicity, plants of Brachiaria brizantha were cultivated on nutritive solution of Hoagland during 90 days and submitted to different concentrations of Pb. The content of macro and micronutrients was evaluated and there was a reduction on root content of Ca, besides the lowest dosages of Pb had induced an increase of N, S, Mn, Cu, Zn and Fe. The cell ultrastructure of leaves and roots were analyzed by transmission electronic microscopy (TEM). Among the main alterations occurred there were invaginations on cell walls, the presence of crystals on the root cells, accumulation of material on the interior of cells and vacuolar compartmentalization. On the leaves the degradation of chloroplasts was observed, as well as the increase of vacuoles. Structures for the formation of oxalate crystals were proposed through molecular modeling and thermodynamic stability. Calculi suggest the formation of highly stable metal-oxalate complexes.
authors.affiliation: Departamento de Química, Universidade Federal de Lavras, UFLA, 37200-000 Lavras, MG, Brazil.
authors.forename: Terezinha Alves
authors.initials: TA
authors.lastname: Tolentino
authors.affiliation: Departamento de Química, Universidade Federal de Lavras, UFLA, 37200-000 Lavras, MG, Brazil; Instituto de Química, Universidade Federal de Alfenas, UNIFAL, 37130-000 Alfenas, MG, Brazil. Electronic address: bertolialexandre@yahoo.com.br.
authors.forename: Alexandre Carvalho
authors.initials: AC
authors.lastname: Bertoli
authors.affiliation: Departamento de Química, Universidade Federal de Lavras, UFLA, 37200-000 Lavras, MG, Brazil.
authors.forename: Maíra
authors.initials: M
authors.lastname: dos Santos Pires
authors.affiliation: Departamento de Química, Universidade Federal de Lavras, UFLA, 37200-000 Lavras, MG, Brazil.
authors.forename: Ruy
authors.initials: R
authors.lastname: Carvalho
authors.affiliation: Departamento de Ciência do Solo, Universidade Federal de Lavras, UFLA, 37200-000 Lavras, MG, Brazil.
authors.forename: Claudia Regina Gontijo
authors.initials: CR
authors.lastname: Labory
authors.affiliation: Departamento de Agricultura e Microbiologia, Universidade Federal de Lavras, UFLA, 37200-000 Lavras, MG, Brazil.
authors.forename: Janaira Santana
authors.initials: JS
authors.lastname: Nunes
authors.affiliation: Departamento de Ciência do Solo, Universidade Federal de Lavras, UFLA, 37200-000 Lavras, MG, Brazil.
authors.forename: Ana Rosa Ribeiro
authors.initials: AR
authors.lastname: Bastos
authors.affiliation: Departamento de Química, Universidade Federal de Lavras, UFLA, 37200-000 Lavras, MG, Brazil.
authors.forename: Matheus Puggina
authors.initials: MP
authors.lastname: de Freitas
mesh_terms: D035201:Brachiaria / Q000378:metabolism* / Q000648:ultrastructure*; D002118:Calcium / Q000378:metabolism*; D056831:Coordination Complexes / Q000378:metabolism*; D007854:Lead / Q000378:metabolism* / Q000633:toxicity; D008958:Models, Molecular; D010070:Oxalates / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism / Q000648:ultrastructure; D018517:Plant Roots / Q000378:metabolism / Q000648:ultrastructure; D013816:Thermodynamics
chemical_list: D056831:Coordination Complexes; D010070:Oxalates; D007854:Lead; D002118:Calcium
keywords: Oxalate crystals; Pb; Raphids; Structural analysis