Plant Disease Management Through Microbiome Modulation

Abstract

In the last few decades, biological approaches have shown significant advancement in the field of agriculture and pest management. The plant microbiome is a rich assemblage of bacteria, fungi, and other microbes that directly influence the rhizosphere’s functioning, plant development, and disease management. It is structurally, chemically, and functionally diverse and is regarded as an additional genome of the plant. The microbiome remains in a harmony with the plant and a slight change in the microbiome population e.g., pathogen invasion may disturb the plant growth and health. Modulation of rhizosphere microbiome by inoculation with beneficial antagonistic microbes has great potential for maintaining optimal rhizosphere environment, plant growth, and promoting plant’s tolerance against diseases. The antagonistic bacteria work through various biocontrol mechanisms such as the lytic enzymes, battle for iron, nutrient uptake and mobilization, antibiosis, and induced resistance. Amongst these, antibiosis is inspiring researchers to explore microbial communities with an ability to control plant diseases as efficiently as chemical products. Microbial antibiotics are small molecules released as secondary metabolites that are efficient at very low concentrations. Biocontrol-PGPR secretes numerous antifungal metabolites, these include 2,4-Diacetylphloroglucinol, ammonia, hydrogen cyanide, ethylene, pyrrolnitrin, zwittermicin, fengycins, phenazines, surfactins, pyoluteorin, mycosubtilin, iturins, and numerous other metabolites. Researchers are using these beneficial antagonistic bacteria and their metabolites to formulate biological products, and several of these registered products are commercially available. This chapter will explicitly describe the past research, recent advances, and future perspectives of plant disease management by microbiome intervention.