Antioxidant Defense Response in Plants to Cadmium Stress

Abstract Cadmium (Cd) is a heavy metal highly toxic to plants and human and animal health. The increased concentration of this metal in the environment in recent decades is the result of anthropogenic activities that include the production of mineral fertilizers, pesticides, intense mining, waste disposal, and foundries. Cd accumulation is known to induce oxidative stress in plant cells due to overproduction of reactive oxygen species, which may result in severe damage at the cellular level, ultimately impairing plant growth and productivity. In response to such stress, different molecules having enzymatic or nonenzymatic actions contribute to mitigate plant cellular damage and balance redox homeostasis in plant cells. This chapter aims to summarize current knowledge about the prospecting of important components of the molecular mechanisms associated with antioxidant machinery in plant response and tolerance to Cd toxicity. Insights into antioxidant response regulation, which includes hormones, signaling molecules, transcription factors, and microRNAs, are also presented.