Uptake of chromium by Salvinia minima : Effect of plant growth, leaf respiration and carbohidate metabolism

CAROLINA PRADO, LUISA RODRIGUEZ-MONTELONGO, JUAN A. GONZÁLEZ, EDUARDO A. PAGANO, MIRNA HILAL, FERNANDO E. PRADO

JOURNAL OF HAZARDOUS MATERIALS.

ELSEVIER SCIENCE BV

Año: 2010 p. 546 - 553

0304-3894

Metabolic responses to chromium (Cr) exposure and metal uptake were investigated using Salvinia minimaSalvinia minima plants. Cr treatment reduced the dry weight of floating and submerged leaves, while photosynthetic pigments were not affected. Measurements of respiratory oxygen uptake with and without inhibitors (KCN and SHAM) demonstrated that total respiration, alternative oxidase capacity and residual respiration were higher in Cr-treated than in Cr-untreated leaves, but the highest values were observed in floating leaves. Cr affected the soluble sugar content. Sucrose concentration was, in general, higher in Crtreated than in Cr-untreated leaves, while the glucose concentration showed an inverse pattern. Cr also affected soluble acid invertase activity, but affectation trend was different between both leaves. Highest values of invertase activity were observed in Cr-treated floating leaves. According to our data soluble acid invertase and sucrose seem to be related to alternative oxidase capacity and residual respiration in floating and submerged leaves exposed to Cr. Thereby, this study constitutes an important contribution to understand metabolic relationships between mitochondrial respiration, alternative respiratory pathway and soluble carbohydrates in plants exposed to heavy metals.