Molecular distribution and toxicity assessment of praseodymium by Spirodela polyrrhiza.

•Pr was mainly bound to cellulose and pectin in Spirodela polyrrhiza.•Pr induced the change in CO, CH, and OH stretching vibration by FTIR.•Pr induced per oxidation of unsaturated fatty acids in membrane lipids.•Pr could target the reaction center proteins D1 and D2.•The reduction in photo system II activity was detected under Pr exposure.