Response of silicon on metal accumulation, photosynthetic inhibition and oxidative stress in chromium-induced mustard (Brassica juncea L.)

•Cr stress inhibits the growth attributes and physiology of mustard plants.•Accumulation of H2O2 and lipid peroxidation induced due to Cr toxicity.•Exogenous application of Si ameliorates Cr-induced toxicity in mustard plant.•Si supplementation reduces Cr uptake thus improving photosynthetic activity.

Silicon plays an important role in the amelioration of heavy metal stress. We have examined the effects of exogenously applied Si (500μM and 700 μM) in the metal accumulation, photosynthetic protection, and oxidative stress under chromium (Cr) stress in mustard (Brassica juncea L.) cv. Varuna. The experimental work was carried out in the naturally illuminated green house in the Department of Botany, Aligarh Muslim University, Aligarh. Plants grown with Cr (100 μM) alone revealed increased oxidative stress via enhancement in H2O2 content and lipid peroxidation. Si protects the plant under Cr stress by reducing transportation of Cr from root to aerial part and also protected photosynthetic activity through increased activity of the net photosynthetic rate, chlorophyll, and carotenoid content. Application of 700 μM Si significantly alleviated the Cr-induced photosynthetic inhibition oxidative stress more than 500 μM Si. The treatment of Si increased proline and ascorbate content which might help increase photosynthetic and growth attributes.