Impact of copper toxicity on physiological and biochemical parameters in Vigna radiata L. plants

Abstract

Copper (Cu) is a toxic metal that accumulates in soil due to agricultural and industrial activities, potentially impacting plant growth and productivity. Our study examined the phytotoxic effects of Cu on Vigna radiata L. by exposing plants to a series of Cu concentrations (1, 4 and 7 mM) under controlled conditions. Growth parameters, photosynthetic performance, biochemical traits, and oxidative stress indicators were analyzed in 21-day-old Cu-treated plants and compared with control plants. The results demonstrated a concentration-dependent decline in shoot and root biomass, relative water content (RWC), pigment content, photosynthetic efficiency, carbohydrates, and lipid content. Conversely, oxidative stress markers such as malondialdehyde (MDA), electrolyte leakage, superoxide dismutase (SOD) and ascorbate peroxidase (APX) activity and proline accumulation increased significantly with increasing Cu concentrations, indicating cellular damage. Notably, protein levels increased with increased Cu concentrations, which may contribute to their tolerance to metal stress, however, it was insufficient to mitigate stress. Further research is needed to validate these findings and explore the mechanisms underlying copper stress tolerance.