Effect of Silicon Application on Cadmium Uptake and Distribution in Strawberry Plants Grown on Contaminated Soils

Silicato de cálcio como amenizante da toxidez de metais pesados em mudas de eucalipto

“…O efeito na diminuição dos teores de Zn e Cd na parte aérea das plantas foi maior no solo com contaminação severa (Figuras 3). Estudos recentes têm sugerido que precipitados eletrodensos de metais pesados com o Si, encontrados na superfície foliar, nos espaços intercelulares, na parede celular dos vasos do xilema e no vacúolo, podem ser responsáveis pela prevenção da absorção excessiva desses elementos, o que refletiria em maior tolerância das plantas à contaminação do solo (Neumann & Zur Nieden, 2001;Treder & Cieslinski, 2005).…”

“…Escórias diversas, especialmente as ricas em silicatos, têm sido estudadas quanto ao efeito na diminuição da mobilidade dos metais, por meio de mudanças no pH do solo (Li et al, 2008). As escórias básicas constituemse de silicatos de Ca e Mg que, além de fornecer esses nutrientes às plantas, atuam como corretivos da acidez do solo, são fontes de Si (Lima Filho et al, 1999) e amenizam a toxidez de metais no solo (Ma, 2004;Treder & Cieslinski, 2005;Kirkham, 2006).…”

Silicon-Mediated Tolerance to Metal Toxicity

“…After analysing Cd content in roots and comparing the total Cd content in plants, Zhang et al ( 2008 ) found both Cd content in roots and the ratio increased signifi cantly by Si treatment, indicating that the exogenous Si supply signifi cantly enhanced Cd retention in the roots and inhibited the root-to-shoot Cd translocation. Si-mediated Cd uptake and translocation were observed not only in Si-accumulating plant species such as rice and maize but also in non-Si accumulators such as pakchoi (Song et al 2009 ) and strawberry ( Fragaria vesca ) (Treder and Cieslinski 2005 ). As can be seen in Fig.…”

“…It was also reported that Si used as soil amendment prior to planting was effective in preventing excessive Cd uptake by strawberry plants grown on sandy soil, and this effect was observed in stems, leaves and fruits but not in roots (Treder and Cieslinski 2005 ). However, foliar application of potassium silicate did not reduce the concentration of Cd in the individual parts of strawberry plants (Treder and Cieslinski 2005 ). More importantly, such inhibitory effects of Si on root-toshoot Cd translocation were species dependent.…”

“…5.7 , the addition of 1.5 mM Si signifi cantly decreased Cd concentration in shoots but increased Cd concentration in roots of pakchoi grown hydroponically with 0.5 or 5.0 mg Cd L −1 (Song et al 2009 ). It was also reported that Si used as soil amendment prior to planting was effective in preventing excessive Cd uptake by strawberry plants grown on sandy soil, and this effect was observed in stems, leaves and fruits but not in roots (Treder and Cieslinski 2005 ). However, foliar application of potassium silicate did not reduce the concentration of Cd in the individual parts of strawberry plants (Treder and Cieslinski 2005 ).…”