Enhanced antioxidant potential and regulated photosynthetic machinery on MgO-NPs exposure induced heavy metal lead stress tolerance in radish

Le résumé fourni par la source

The increasing population, challenging climatic and environmental conditions are significantly affecting crop productivity and agriculture. Radish, a nutritious root vegetable, is documented to be considerably affected by abiotic stresses, including heavy metal stress. Heavy metal stress has been found to influence the growth, development, and productivity of radish worldwide. As nanotechnology has increasingly affected various fields, including agriculture, nanomaterials are being explored as a sustainable solution to enhance crop productivity and mitigate stress. Given this, the present study investigates the potential of biologically synthesized MgO-NPs for regulating lead stress in radish. Radish seeds were exposed to 0.075 mM (L1), 0.15 mM (L2), and 0.3 mM (L3) of lead nitrate to induce lead stress. The lead stress was observed to significantly reduce the shoot and root length of radish by 24–56% and 13–69% in a concentration-dependent manner. Further, a considerable drop of 36% in the total chlorophyll content reduced the carbohydrate and protein levels by 7 and 21%, respectively. A likewise reduction in the non-enzymatic and enzymatic antioxidant parameters evidently decreased the free radical scavenging potential of lead-stressed radish by 5% and enhanced the oxidative stress by 43%. During the study, the radish seeds were nanoprimed with 150 µg/ml of MgO-NPs, which considerably rescued the morphological and biochemical traits of lead-stressed radish. MgO-NPs mediated 43 and 91% enhancement in the shoot–root length, evidently elevated the fresh biomass accumulation of lead-stressed radish by 73%. Further, NPs mediated reduction in the photosynthetic parameters and enhanced antioxidant parameters, elevated the antioxidant potential of lead-stressed radish by 3%, which significantly downregulated the H 2 O 2 and MDA levels by 13 and 8%, thus reducing oxidative stress. Hence, MgO-NPs triggered an overall coordinated physiological and biochemical response in lead-stressed radish, as marked by the enhanced morphological traits, increased antioxidant defence, and regulated photosynthetic accumulation, thereby alleviating the lead-induced toxicity in radish.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.