Molecular mechanisms of methyl jasmonate (MeJAs)-mediated detoxification of heavy metals (HMs) in agricultural crops: An interactive review

Abstract

Heavy metals (HMs) and metalloids such as lead (Pb), cadmium (Cd), and arsenic (As), are significant soil contaminants worldwide that pose a substantial threat to agricultural productivity and human health. Therefore, to reduce HM buildup in plants, mitigation/detoxification strategies must be developed. For phytoremediation, plants with the ability to hyper-accumulate and hyper-tolerate dangerous minerals—both naturally occurring and genetically modified—have promise. To date, only a small number of plant species, including Arabidopsis and Oryza, have been utilized to illustrate the molecular processes of plant detoxification and/or HMs buildup. Methyl jasmonate (MeJA), a biostimulant plays a crucial role in improving plant tolerance to various environmental stresses including HM toxicity. In this review, the physiological and molecular reactions of MeJAs for HMs are discussed. MeJA reduces metal accumulation and increases resistance to HMs by coordinating the ion transport system, antioxidant enzyme activities, and chelating capacity in plants. The Ca²⁺ signaling has been proposed as a potential contributor to the production of jasmonate that is brought on by plant stress. The primary gene families participating in JA-responsive pathways are identified using comparative transcriptomics analysis utilizing available datasets. The evolutionary conservation and diversity of these gene families seen in a significant number of species belonging to the primary lineages of green plants discussed in this research lend credence to the notion that JAs act as phytohormones that protect plants from HMs/metalloids.

By utilizing the ATP-Binding Cassette-G (ABCG) transporter subfamily of six common green plant species, the JA transporters in Subgroup 4 of ABCGs may potentially contribute to HM detoxification. This review may help in the selection and development of suitable HMs-resistant crop species.