Cr(VI) Imposed Toxicity in Maize Seedlings Assessed in Terms of Disruption in Carbohydrate Metabolism

Abstract

The present study examined the toxic effects of Cr(VI; 100, 250 and 500 μM) in maize seedlings by investigating the changes in carbohydrate metabolism after 48, 96, and 144 h of exposure. Cr-stress results in severe alterations in the contents of carbohydrates and reducing sugars and the activities of carbohydrate metabolizing enzymes, amylases, phosphatases and phosphorylases, and invertases in maize seedlings. Under Cr stress, the contents of carbohydrates and reducing sugars declined in roots, whereas an increase was noticed in leaves. The catalytic activity of carbohydrate metabolizing enzymes, except invertases, in roots declined in the presence of Cr(VI) in a concentration- and exposure time-dependent manner. In contrast, the activities of these enzymes were enhanced in leaves under Cr(VI) stress. The activity of invertases increased with increasing amount of Cr(VI) but declined with an increase in the time interval. In conclusion, our results show that carbohydrate metabolism is severely affected under Cr(VI) toxicity. The study suggests that Cr-induced perturbations in the carbohydrate metabolism are one of the factors resulting in growth inhibition under Cr(VI) stress.

Gomphrena claussenii, a novel metal‐hypertolerant bioindicator species, sequesters cadmium, but not zinc, in vacuolar oxalate crystals

“…Specifically, for toxic metal exposure, a decrease in chlorophyll content, and therefore carbon assimilation, has been described as a metal toxicity symptom for metal‐sensitive plants (Alaoui‐Sossé et al ., ; Maksymiec, ). Similarly, a reduction in sugar concentrations has been reported for roots (Costa & Spitz, ; Podazza et al ., ; Mahajan et al ., ) and, at very high exposures, for shoots as well (Ci et al ., ; Nayek et al ., ). Plants tolerant to high metal exposure maintain photosynthesis rates and show an increase in soluble sugar concentrations in roots (Chinmayee et al ., ; He et al ., ), as found here for G. claussenii .…”

Is intraspecific trait differentiation in Parthenium hysterophorus a consequence of hereditary factors and/or phenotypic plasticity?

“…The activities of α - and β -amylases were determined using the method given by Mahajan et al (2013) . One hundred milligrams of the fresh plant tissue (leaf/root) were homogenized in 10 ml of 0.1 M sodium phosphate buffer (pH = 7).…”

Suprimento de enxofre e a toxidez por cromo no capim tanzânia

“…Para que as plantas apresentem elevada produção de massa seca há necessidade de bom crescimento radicular, com comprimento e superfície desenvolvidos visando maior absorção de nutrientes . A toxidez por Cr fez com que as plantas apresentassem menores comprimentos das raízes do capim tanzânia (Figura 5c), da mesma forma que o encontrado para milho (Zea mays), Arabidopsis (Arabidopsis thaliana) e arroz (Oryza sativa) (Cao et al 2013;Mahajan et al 2013;. Observou-se também que para o capim tanzânia a toxidez por Cr causou efeito repressor na área superficial radicular (Figura 5a).…”