Biochemical responses of pea plants to drought stress and in the presence of molybdenum trioxide nanoparticles

Aims To study the effect of an aqueous suspension of MoO 3 NPs on drought-affected peas by watering and spraying and to evaluate their effect on the amount of Mo in different parts of the plant and in the soil. Methods The experiments were conducted in a greenhouse under a natural daylight photoperiod. Pea plants were treated with 12.5, 25, and 50 ppm concentrations of MoO 3 NPs suspension before ten days of drought when substrate moisture was maintained at 30%. This research investigated the nanoparticle suspension's properties and the different treatment mechanisms by watering and spraying plants. The effects of MoO 3 NPs and drought on growth parameters were evaluated. The impact on the enzymatic (SOD, CAT, APX, GPX, GR), non-enzymatic (DPPH, ABTS, FRAP, TPC) antioxidants, and oxidative stress biomarkers (MDA, H 2 O 2 amount) were determined. Elemental analysis was performed on different plant parts. Results The results showed that 50 ppm MoO 3 NPs significantly increased the yield, height, leaf area, and nodule number of a drought-stressed pea. Furthermore, MoO 3 NPs significantly activated CAT, APX, SOD, and GPX enzymes and increased total phenolic compounds. Conclusions Increasing MoO 3 nanoparticles concentration influenced the resistance of pea plants to drought stress by positively affecting the antioxidant activity of pea plants, which led to an increase in growth parameters and the number of nodules, which possibly accelerated the accumulation of mineral nitrogen in the soil and could be associated with an increase in yield. The highest Mo accumulation occurred in the roots after exposure through the soil. Graphical abstract