Salicylic Acid Modulates Plant Tolerance Against Metal Toxicity

Metals at optimum level are necessary for plants and human heaths. However, their excess is dangerous for living organisms. Heavy metals can alter the permeability of mitochondrial membranes and limit the activity of reactive oxygen species (ROS) clearance enzymes in the cellular antioxidant system. However, they cause plants to produce excessive amounts of ROS. The buildup of environmental contaminants and oxidative stress in exposed species is caused by the interaction of ROS with cellular membranes, heavy metal-induced interactions with various macromolecules either directly or indirectly, and signaling pathways. Numerous pathogenic processes, including energy depletion, excessive ROS production, mitochondrial respiratory chain damage, decoupling of oxidative phosphorylation, and mitochondrial death, are obstructed by the heavy metal–ROS–cell signaling axis. Salicylic acid had excellent potential mitigates adverse effects of metal toxicity by regulation of plant growth, photosynthetic pigments, and antioxidant defense system in plants.