Oxidative effects and metabolic changes following exposure of greater duckweed (Spirodela polyrhiza) to diethyl phthalate

► Effects of DEP, a potent allelochemical, on the growth of duckweed were studied. ► We examine changes in the level of growth, ROSs, and antioxidants responses. ► DEP promotes plant growth and increases chlorophyll accumulation at 0.25 mM. ► DEP is toxic and induces oxidative stress at concentrations from 0.5 to 2.0 mM. ► Antioxidant enzymes play important roles in the defense strategy against DEP stress.