Organosilicon and inorganic silica inhibit polystyrene nanoparticles uptake in rice

Nanoplastics (NPs) have become an emerging global environmental problem, and the toxicity of polystyrene nanoplastics (PS-NPs) in rice plants has received widespread attention. However, few studies have focused on silicon (Si)-mediated interactions between PS-NPs and rice. Thus, two forms of Si (organosilicon/inorganic silica) treated rice cells were exposure of positively or negatively charged NPs, PS-NH and PS-COOH, to evaluate the effects of Si for defense against PS-NPs toxicity in rice. The result showed PS-NH nanoparticles were accumulated at relatively low levels in cells compared with that of PS-COOH, but induced a higher accumulation of hydrogen peroxide (HO) and superoxide radicals (O). However, both organosilicon and inorganic silica can generate more negative potential on the surfaces of cell wall to absorb large numbers of positively charged PS-NH. In addition, they can prevent the uptake of both PS-NH and PS-COOH through reducing the porosity on the surface of the cell walls. These finally alleviated the toxicity of oxidative stress caused by PS-NPs and improved the viability of rice cells. Our findings demonstrated the significant contribution of Si in combating PS-NPs in rice.