Mechanisms of Plant Defense Under Pathogen Stress: A Review

Being sessile organisms, plants are persistently confronted by a diverse array of biotic agents, including viruses, bacteria, fungi, herbivores, and nematodes. Understanding the mechanism of host-pathogen interactions is essential for improving plant resistance against these biotic factors. In this review, we have discussed various means and mechanisms by which pathogens influence the host plant defense. A virulent pathogen can reduce the growth and development of a plant, which eventually lowers its yield by multiple processes, like enhancement in cell death, as well as modification of plant architecture. This review also explains the various strategies used by plants to control pathogen-caused diseases. These mainly include either resistance or tolerance by activating cell signaling pathways, which further regulate the synthesis and accumulation of several cellular products, such as phytohormones, enzymes, proteins, and secondary metabolites. To minimize the influence of infection on their vigor, plants also exhibit immunity regardless of the amount of pathogen multiplication. The current review provides an important insight into the mechanisms of host-pathogen interaction, which is very significant for efficient disease management.