A comparison of the effects of copper nanoparticles and copper sulfate on Phaeodactylum tricornutum physiology and transcription.

Copper nanoparticles (CuNPs) have been used in a broad range of applications. However, they are inevitably released into the marine environment, making it necessary to evaluate their potential effects on marine phytoplankton. In this study, the short-term (96 h) effects of CuNPs and CuSO 4 on Phacodactylum tricornutum growth, photosynthesis, reactive oxygen species production and transcription were assessed. It was found that high concentrations (40 μM) of CuNPs and CuSO 4 significantly inhibited the growth, photosynthesis and induced oxidative stress of P. tricornutum, while lower concentrations caused a hormetic response as indicated by a slight stimulation in algal growth. The high percentage of dissolved Cu (78–100%) in culture medium suggested that the dissolved Cu was the main driver of toxicity during CuNPs treatment. The algal cells upregulated electron transport chain-related genes to produce more energy and restore photosynthesis after 96 h of treatment with CuNPs and CuSO 4 . This study delineates the cellular mechanism behind the toxicity of CuNPs and CuSO 4 on marine diatoms. [ABSTRACT FROM AUTHOR]