a, Localization of PS-COOH (indicated by red fluorescence) and PS-NH2-F (green fluorescence) in roots incubated for seven days. Scale bars, 100μm. b, Scanning TEM (STEM) images of roots from non-treated (control) and PS-Pd-treated plants. Scale bars, 1μm. c, Graphic showing the uptake of differentially charged nanoplastics in an Arabidopsis root and the plant defence mechanisms that are induced in response to nanoplastics.