title: Effect of lead stress on mineral content and growth of wheat (Triticum aestivum) and spinach (Spinacia oleracea) seedlings.
abstract: Lead (Pb) is the most common heavy metal contaminant in the environment. Pb is not an essential element for plants, but they absorb it when it is present in their environment, especially in rural areas when the soil is polluted by automotive exhaust and in fields contaminated with fertilizers containing heavy metal impurities. To investigate lead effects on nutrient uptake and metabolism, two plant species, spinach (Spinacia oleracea) and wheat (Triticum aestivum), were grown under hydroponic conditions and stressed with lead nitrate, Pb(NO3)2, at three concentrations (1.5, 3, and 15 mM). Lead is accumulated in a dose-dependent manner in both plant species, which results in reduced growth and lower uptake of all mineral ions tested. Total amounts and concentrations of most mineral ions (Na, K, Ca, P, Mg, Fe, Cu and Zn) are reduced, although Mn concentrations are increased, as its uptake is reduced less relative to the whole plant's growth. The deficiency of mineral nutrients correlates in a strong decrease in the contents of chlorophylls a and b and proline in both species, but these effects are less pronounced in spinach than in wheat. By contrast, the effects of lead on soluble proteins differ between species; they are reduced in wheat at all lead concentrations, whereas they are increased in spinach, where their value peaks at 3 mM Pb. The relative lead uptake by spinach and wheat, and the different susceptibility of these two species to lead treatment are discussed.
authors: PER-Centre des Etudes Environnementales Méditerranéennes, Equipe de recherche Biotechnologies et Génie des Biomolécules, Université Abdelmalek Essaadi, Faculté des Sciences et Techniques, BP 416, Tangier, Morocco.
authors: Mostafa
authors: M
authors: Lamhamdi
authors: Ouiam
authors: O
authors: El Galiou
authors: Ahmed
authors: A
authors: Bakrim
authors: Juan Carlos
authors: JC
authors: Nóvoa-Muñoz
authors: Manuel
authors: M
authors: Arias-Estévez
authors: Ahmed
authors: A
authors: Aarab
authors: René
authors: R
authors: Lafont
keywords: Chlorophyll; Heavy metal stress; Nutrient elements; Proline; Soluble protein; Spinach; Wheat
references: Protoplasma. 2007;231(1-2):99-111
references: 17370112
references: Bioresour Technol. 2008 Oct;99(15):6771-9
references: 18331789
references: Plant Physiol. 1982 Jun;69(6):1376-81
references: 16662407
references: C R Biol. 2011 Feb;334(2):118-26
references: 21333942
references: Environ Sci Technol. 1997 Apr;31(4):182A-6A
references: 21650618
references: Plant Physiol. 1995 Dec;109(4):1141-9
references: 8539285
references: Acta Biol Hung. 1991;42(4):331-44
references: 1841484
references: Rev Environ Contam Toxicol. 2008;196:73-93
references: 19025093
references: Anal Biochem. 1976 May 7;72:248-54
references: 942051