Assessment of Various Toxicity Endpoints in Duckweed (Lemna minor) at the Physiological Biochemical and Molecular Levels as a Measure of Diuron Stress

摘要

The presence of diuron in a variety of environments has been reported worldwide to exert serious harm to human health and the ecosystem. HPLC and mass spectrometry are highly specific and sensitive methods for herbicide detection, but they have several drawbacks including complex sample preparation procedures, the need for expensive chemicals and equipment, and interference from secondary contaminants during analysis. In addition, these purely chemical approaches do not provide ecologically meaningful information on temporal changes in terms of exposure or the interactive effects of pollutants. In order to compensate for these limitations, biological assays have been used to assess pollutant-induced ecological risks. Lemna minor is an attractive experimental model organism that has been used for decades for the prospective risk assessment of pesticides. In the current study, we examined the effects of diuron on L. minor using different endpoints at the physiological (growth and photosynthetic efficiency), biochemical (pigment biosynthesis and reactive oxygen species (ROS) levels), and molecular (gene transcription) levels. Our findings provide important insight into the relative sensitivity of different endpoints for diuron toxicity assessment. In addition, they shed light on the toxicity mechanisms of diuron in a model aquatic macrophyte species.