Chromium oversupply induces harmful impacts on Mentha arvensis L. by destabilizing photosynthetic machinery and other physiological markers

Abstract

Chromium (Cr) is the seventh most toxic heavy metal on the earth's crust. Crop growth, development, and yield are greatly hindered by the massive accumulation of Cr that discharges from various industries and mines in agricultural land. Chromium can mediate phytotoxicity either via direct interaction with multiple plant components and metabolic pathways or by promoting reactive oxygen species (ROS) generation. Thus, this investigation evaluated the effect of Cr on growth, physiological and oxidative stress, and other parameters, including essential oil (EO) constituents of Mentha arvensis L. plants. The soil was treated with various concentrations of Cr (10, 20, 40, 60, and 80 mg kg−1), except the control. In this study, 20 mg kg−1 of Cr concentration was beneficial in increasing plant growth via the enhancement of biomass, photosynthesis, biochemical markers and EO constituents in M. arvensis. The data demonstrated that the morphological and physiological parameters were negatively correlated with high Cr concentrations (above 20 mg kg−1). It has been hypothesized that Cr poisoning leads to oxidative damage, as evidenced by decreases in photosynthetic rate, chlorophyll, and stomatal characteristics, as well as increases in lipid peroxidation and ROS. The accumulation of Cr positively correlates with the enhancement of proline and antioxidant activities of M. arvensis. Thus, we concluded that excess Cr causes redox imbalance by uplifting the level of lipid peroxidation and ROS by destabilizing photosynthetic machinery and other physiological and morphological markers in plants.