Enhancing photosynthetic efficiency and antioxidant activity in camelina under cadmium stress through foliar silicon application
Amnah M. Alamri, Hesham F. Alharby, M. Naeem, Muhammad Adnan Bukhari, Zahoor Ahmad, Abid Mahmood Alvi, Ali Majrashi, Basmah M. Alharbi
Abstract
Silicon (Si) plays a pivotal role in enhancing plant resilience against abiotic stressors, yet the precise mechanisms underlying its potential in mitigating cadmium toxicity in camelina remain poorly elucidated. This study focuses on examining the impact of different treatments of foliar Si such as 0 ppm Si with 0 ppm Cd (T0Cd0), 2.5 ppm Si with 0 ppm Cd (T1Cd0), 5 ppm Si with 0 ppm Cd (T2Cd0), 0 ppm Si with 5 ppm Cd (T0Cd1), 2.5 ppm Si with 5 ppm Cd (T1Cd1), and 5 ppm with 5 ppm Cd (T2Cd1) application on two camelina cultivars cultivated under hydroponic conditions of cadmium-induced stress. Cadmium stress significantly impaired various aspects of plant development, including growth parameters, photosynthetic pigments, and the activities of key antioxidant enzymes such as superoxide dismutase, peroxidase, ascorbate peroxidase, and catalase. Additionally, cadmium accumulation was higher in both root and leaf tissues under stress. The Canadian cultivar demonstrated greater susceptibility to cadmium at a concentration of 5 ppm compared to the Australian cultivar. However, the introduction of silicon at a concentration of 5 ppm effectively alleviated the toxic effects of cadmium, with the Australian cultivar showing a more substantial response relative to the Canadian counterpart. These findings highlight silicon’s crucial role in mitigating cadmium toxicity in camelina, enhancing growth and antioxidant defenses under stress.