Agronomic, breeding, and biotechnological interventions to mitigate heavy metal toxicity problems in agriculture

Abstract

Heavy metal toxicity (HMT) is a major threat to agriculture production and productivity worldwide; it affects the yield potential of the major food crops. It impairs the plant's physiological function, reduces seed germination, produces oxidative stress, and hinders the plant's photosynthetic ability. Plants absorb these heavy metals from the contaminated soils and cause severe health complications to those consuming the products grown out of the contaminated sites. The major contributor to HMT is human and human-related activities. Therefore, it is very important to address the HMT problem in agriculture. Agronomic interventions such as bioremediation using either plants (phytoremediation) or microbes (microbial bioremediation) is one of the effective methods to remove heavy metals from the soil. More than 400 plant species were reported as hyperaccumulators of various heavy metals. Breeders may develop heavy metal tolerant crop cultivars through breeding and biotechnological interventions for wider adaptation. Several heavy metal tolerant crop cultivars have been developed and commercialized for various economically important food crops. Leveraging omics, gene editing, and high throughput screening tools may speed up the cultivar development. Therefore, we focus on reviewing the agronomic, breeding, and biotechnological interventions to mitigate the HMT problem in agriculture, along with sensors for heavy metal detection to speed up the screening process. • Heavy metal toxicity is a major threat to agriculture production and productivity worldwide; it affects the yield potential of the major food crops. • Plants absorb heavy metals from the contaminated soils and cause severe health complications to those consuming the products grown out of the contaminated sites. • Agronomic interventions include phytoextraction, phytostabilization, phytostimulation, phytovolatilization, phytofiltration, and phytodegradation are very effective in removing heavy metals from contaminated sites. • Breeding interventions are vital to identify the resistant sources from the gene pool and develop resistant cultivars; breeders developed heavy metal tolerant cultivars in many economically important crop species. • Biotechnological (gene targets and genetic engineering) and engineering (real-time sensors for heavy metal detection and quantification) interventions are the need of the hour to improve and mitigate the heavy metal toxicity problem in agriculture.