Heavy metal and metalloid stress in plants: the genomics perspective.

Abstract

Abstract Heavy metal and metalloid stress are major abiotic stress factors that limit crop production and reduce agricultural yield. Beside natural factors, human activities have contributed to the enormous increase in heavy metal and/or metalloid pollution in the environment. Both heavy metals and metalloids exert deleterious impacts on plant growth and development. High production of reactive oxygen species (ROS) results in oxidative damage to important cellular components. Our understanding of these factors and the key mechanisms involving a wide array of genes and their expression is far from complete. In the past few decades, several molecular mechanisms were identified, which are particularly related to heavy metal transport and hypertolerance. Moreover, expression profiles of several major genes associated with heavy metal/metalloid stress were elucidated and provided vital insights to our understanding of heavy metal stress in plants. This review focuses on the molecular physiology of heavy metal and metalloid stress in plants. We discuss here the aspects related to the physiology of heavy metal stress, ROS and several molecular events that are associated with metal tolerance.