ABSTRACT
Among many soil problems, heavy metal accumulation is one of the major agronomic challenges that has seriously threatened the health of plants, animals and humans when they enter the food chain. In recent years, an estimated 12.6 million people have died from > 100 diseases worldwide caused by unhealthy and poor environmental conditions including contaminated soils. Due to these problems, soil biologists/agronomists in recent times have also raised concerns over heavy metal pollution, which is adversely affecting agro-ecosystems and crop production. The toxic heavy metals once deposited beyond certain permissible limits, can seriously affect the physiological and metabolic activities of plants, leading eventually to a reduction in Avena sativa production and entering the food chain to affect human and animal health. Therefore, metal-induced phytotoxicity problems warrant urgent and immediate attention so that the physiological activities of the plant, the nutrient pool of soils and concurrently the production of oat are preserved and maintained in a constantly deteriorating environment. To mitigate the magnitude of metal-induced changes, mechanisms responsible for reduced oat plant growth rate, photosynthetic machinery, transpiration rate, oxidative and metabolic stress and key genes expressed in response to particular heavy metals stress have been critically analyzed. Despite some intermittent reports, the phytotoxicity of heavy metals to oat and how oat production in metal-stressed soil can be enhanced have been poorly examined. Thus, an attempt is made in this chapter to better understand the mechanistic basis of metal toxicity to Avena sativa. The information provided here is likely to benefit researchers in formulating heavy metal remediation strategies and consequently optimize oat production inexpensively under heavy-metal-stressed soils.
