Potential of MgO and MgCO3 nanoparticles in modulating lettuce physiology to drought

Drought is of great concern for agriculture due to its negative impact on crop development and yield, which is being aggravated by climate changes. Aware of that, the present work explores the use of MgO and MgCO3 nanoparticles (nMgO; nMgCO(3)) as potential mitigating agents of drought stress effects in lettuce. Stressed and unstressed plants were sprayed with 10 mg L-1 of nMgO, nMgCO(3) or nMgO + nMgCO(3) (Mix) suspensions. Growth parameters, water content, carbohydrates, pigments, and photosynthesis were evaluated after 21 days experiment. Data revealed distinct response of lettuce to nanoparticles application depending on water conditions: unstressed plants accumulated more carbohydrates when treated with nMgO and/or nMgCO(3), and showed higher stomatal limitations; in water stressed plants, nanoparticle treatments induced chlorophyll a, b and carotenoids accumulation (nMgCO(3) and Mix). Concerning chlorophyll a fluorescence parameters, only a trend to increase effective efficiency of photosystem II in unstressed plants treated with nMgCO(3) was observed. Results highlight that nMgO and nMgCO(3) may have potential to modulate photosynthesis, driving plants to boost pigment accumulation under water stress, avoiding putative impairments in the photochemical phase of photosynthesis.

Automated summary

The present study investigates the potential mitigating effects of MgO and MgCO3 nanoparticles on drought stress effects in lettuce. The results show that the nanoparticles can enhance the accumulation of chlorophyll and carotenoids under water stress, improve the efficiency of photosynthesis, and prevent potential impairments in the photochemical phase of photosynthesis.