Foliar application of gibberellic acid endorsed phytoextraction of copper and alleviates oxidative stress in jute (Corchorus capsularisL.) plant grown in highly copper-contaminated soil of China

Copper (Cu) is an abundant essential micronutrient element in various rocks and minerals and is required for a variety of metabolic processes in both prokaryotes and eukaryotes. However, excess Cu can disturb normal development by adversely affecting biochemical reactions and physiological processes in plants. The present study was conducted to explore the potential of gibberellic acid (GA(3)) on fibrous jute (Corchorus capsularisL.) seedlings grown on Cu mining soil obtained from Hubei Province China. Exogenous application of GA(3)(10, 50, and 100 mg/L) on 60-day-old seedlings ofC. capsulariswhich was able to grow in highly Cu-contaminated soil (2221 mg/kg) to study different morphological, physiological, and Cu uptake and accumulation in different parts ofC. capsularisseedlings. According to the results, increasing concentration of GA(3)(more likely 100 mg/L) alleviates Cu toxicity inC. capsularisseedlings by increasing plant growth, biomass, photosynthetic pigments, and gaseous exchange attributes. The results also showed that exogenous application of GA(3)reduced oxidative stress inC. capsularisseedlings by the generation of extra reactive oxygen species (ROS). The reduction in oxidative stress inC. capsularisseedlings is because that plant has strong enzymatic antioxidants [superoxidase dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), and catalase (CAT)], which ultimately increased their activities to overcome oxidative damage in the cells/tissues. In addition to the plant growth, biomass, and photosynthesis, foliar application of GA(3)also helps to increase metal (Cu) concentration in different parts of the plants when compared to 0 mg/L of application of GA(3). From these findings, we can conclude that foliar application of GA(3)plays a promising role in reducing ROS generation in the plant cells/tissues and increased phytoextraction of Cu in different plant parts. However, more investigation is needed on field experiments to find a combination of GA(3)with a very higher concentration of Cu using fibrousC. capsularis.