Manganese induced changes in growth, chlorophyll content and antioxidants activity in seedlings of broad bean (Vicia faba L.).

ABSTRACT

The effect of manganese(Mn) on broad bean (Vicia faba L.) was studied with regard to growth, Mn accumulation in root and shoot, chlorophyll, proline content and peroxidase activity. Seeds were treated with Mn (10, 20, 40, 80,120,160 μM) and grown hydroponically up to 15 days. Manganese level in both root and shoot increased progressively in response to increasing concentration and it was high in roots (13 fold) over the shoots (8 fold). The reductions in root (52%) and shoot (62.92%) development were evident for the maximum Mn concentration (160 μM). The chlorophyll amount gradually declined with increasing Mn concentrations and attained its maximum (42%) at 160 μM. By contrast, the guaiacol peroxidase activity was high (71%) along with the accompanying rise in proline content (75%) in shoots of the highest Mn concentration (160 μM). However, there was about 2 fold increase in total glutathione content at 40 μM than the basal level and further declined to 21.65 Cg g-1 fresh wt. at 160 μM Mn. The alterations in overall reflected Mn concentration- dependent changes in the parameters studied. The results suggest that the plant Vicia faba L. copes with Mn exposure through enhanced production of antioxidants.