In search for potential biomarkers of copper stress in aquatic plants

Over the last few decades, the use of pesticides and discharge of industrial and domestic wastewater on water surfaces have increased. Especially, Copper (Cu) pollution in aquatic ecosystems could constitute a major health problem, not only for flora and fauna but also for humans. To cope with this challenge, environmental monitoring studies have sought to find Cu-specific biomarkers in terrestrial and aquatic flora and/or fauna. This review discusses the toxic effects caused by Cu on the growth and development of plants, with a special focus on aquatic plants. While copper is considered as an essential metal involved in vital mechanisms for plants, when in excess it becomes toxic and causes alterations on biomarkers: biochemical (oxidative stress, pigment content, phytochelatins, polyamines), physiological (photosynthesis, respiration, osmotic potential), and morphological. In addition, Cu has a detrimental effect on DNA and hormonal balance. An overview of Cu toxicity and detoxification in plants is provided, along with information regarding Cu bioaccumulation and transport. Awareness of the potential use of these reactions as specific biomarkers for copper contamination has indeed become essential.