The utilization of Ricinus communis in the phytomanagement of heavy metal contaminated soils

Abstract

Soil contamination with toxic metals is a major global concern due to their effects on plants and the ecosystem. In contaminated soils, some plant species have the ability to remediate heavy metals. Ricinus communis L., is an industrial crop plant gaining popularity in the remediation of heavy metal contaminated soils owing to its strong and deep penetrating roots aiding high metal accumulation and large biomass level. Ricinus communis can tolerate high amounts of metals by adopting different strategies, which include the production of antioxidant enzymes, subcellular localization, and exudation of organic acid. At the molecular level, R. communis can tolerate metal stress by activating stress-responsive genes. Proper selection of metal-tolerant R. communis cultivars is effective in the remediation of metal-contaminated soils, owing to their high capacity for metal tolerance. Exogenous application of mineral fertilization and the use of microbes and chelating agents increase metal solubility and availability for plant uptake in soil. Also, good agronomic practices such as co-planting of R. communis with other leguminous crops enhance R. communis growth and metal tolerance, thereby improving remediation of metal-contaminated soils. This review, therefore, critically discusses the recent approaches in using R. communis to remediate metal-contaminated soils.