Efficacy of Alternanthera bettzickiana to Remediate Copper and Cobalt Contaminated Soil Physiological and Biochemical Alterations

Increasing world population triggers intensive agricultural practices responsible for higher heavy metal contamination of soil and water. The present study was conducted to evaluate the morpho-physiological and biochemical response along with phytoextraction potential of Alternanthera bettzickiana for cobalt (Co) and copper (Cu) contaminated soil. Healthy and uniform plants of A. bettzickiana were collected and placed in pots each filled with 5 kg of sandy loam soil. Plants were treated with different concentrations of Cu and Co (2.5, 5, 7.5, and 10 mM). After 8 weeks of treatments, plant agronomic traits such as plant growth, biomass, chlorophyll content, and activities of antioxidant enzymes were measured and results revealed no visual signs of toxicity whereas all characteristics were enhanced as compared to control plants except 10 mM where it significantly decreased the plant’s morpho-physiological and biochemical characteristics. Further, Cu and Co concentration and accumulation in all parts of plants significantly increased with increasing concentration of applied heavy metal. The plants significantly accumulate 2.1 and 2.0 times more Cu in shoots and 1.5 and 1.2 times more Co in roots as compared to controls. The results concluded that A. bettzickiana is a potential hyperaccumulator and halophyte of Co and Cu therefore it can be a potential candidate for the remediation of Cu and Co contaminated sites. Graphic Abstract Article Highlights Alternanthera bettzickiana showed greater tolerance towards copper and cobalt. Higher metal doses altered biochemical functions and decreased agronomic traits. Antioxidant defense system boosted up to scavenge reactive oxygen species production. Alternanthera bettzickiana proved as good hyper-accumulator of cobalt and copper.