Defense Mechanism of Tolerant Plants to Combat Xenobiotics

Environmental pollution from xenobiotics is a worldwide problem driven by human activities like urbanization and population growth. The release of these harmful substances has a widespread, immediate, and long-term impact on the natural ecosystem. The term mainly refers to pollutants like dyes, pesticides, chemical fertilizers, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs), as well as their effects on the environment. Elevated amounts of these xenobiotics disrupt the biotic balance in the soil, leading to the pollution of the soil surface and groundwater. As a result, plants are constantly exposed to these potentially noxious chemicals. Within plants, these xenobiotics interfere with the functional groups of vital molecules such as enzymes, nutrient ion transport systems, and polynucleotides. They also disrupt coordinated signaling pathways, which, in turn, affect gene expression, regulation, growth, and physiology of plant species. Consequently, plants have developed mechanisms to mobilize xenobiotics and have also expanded various detoxification processes to manage them. This review examines the sources of xenobiotics, their effects on plants, and the modulation of these chemicals within plant systems.