The impact of cerium oxide nanoparticles on the physiology of soybean (Glycine max (L.) Merr.) under different soil moisture conditions

Abstract

The ongoing global climate change raises concerns over the decreasing moisture content in agricultural soils. Our research investigated the physiological impact of two types of cerium oxide nanoparticles (CeO₂NPs) on soybean at different moisture content levels. One CeO₂NP was positively charged on the surface and the other negatively charged due to the polyvinylpyrrolidone (PVP) coating. The results suggest that the effect of CeO₂NPs on plant photosynthesis and water use efficiency (WUE) was dependent upon the soil moisture content. Both types of CeO₂NPs exhibited consistently positive impacts on plant photosynthesis at the moisture content above 70% of field capacity (θ_fc). Similar positive impact of CeO₂NPs was not observed at 55% θ_fc, suggesting that the physiological impact of CeO₂NPs was dependent upon the soil moisture content. The results also revealed that V _Cmax (maximum carboxylation rate) was affected by CeO₂NPs, indicating that CeO₂NPs affected the Rubisco activity which governs carbon assimilation in photosynthesis. In conclusion, CeO₂NPs demonstrated significant impacts on the photosynthesis and WUE of soybeans and such impacts were affected by the soil moisture content. Graphical abstract Soil moisture content affects plant cerium oxide nanoparticle interactions.

Keywords: Cerium oxide nanoparticles; Soil moisture; Soybean; Surface charge.