Role of Microbes in Plant Biotic Stress Management

For ages, biotic stress (e.g., pathogens, weeds, and insects) has been considered as a major threat for plants causing yield reductions. Synthetic chemicals have been used for control, but due to their ecotoxicity, a safer and more sustainable alternative tool such as biopesticides is being encouraged. Biopesticides encompass the use of natural agents, such as plants, microbes, and natural enemies (animals), to control plant pests. Among all these agents, microbes are more easily manipulated and their preference relies on their hasty growth rate. Bacteria, fungi, and viruses, when maximally explored, can be efficiently used to control plant pathogen via a multitude of mechanisms. This includes a direct interference with the normal metabolism of the pathogen; an enhancement of plants root physiology; an induction of the host plant systemic resistance, competition, and antagonism; an alteration of the plant-pathogen signaling and parasitism; and the production of different metabolites, such as organic acids, enzymes, and hormones. This chapter summarizes the microbe species involved in biotic stress management and their mechanism (mode of action) and the factors affecting their survival.