Plant Growth–promoting Rhizobacteria: Their Potential as Biological Control Agents in Sustainable Agriculture

Abstract

Microorganisms as biological control agents have received special attention in recent years. Biological control is a sustainable and environmentally friendly method and offers a valid alternative to chemical pesticides. Biological control agents have high adaptability to environmental conditions and various synergistic mechanisms based on the host plant. The role of beneficial soil bacteria that live around the root or the rhizosphere and improve plant growth, known as plant growth–promoting rhizobacteria (PGPRs), is very important. PGPRs directly (dissolving of minerals, nitrogen fixation, production of plant hormones such as auxins, gibberellins, and cytokinins) or indirectly (production of several substances such as antibiotics, siderophores, lytic enzymes, volatile organic compounds, hydrogen cyanide, and also competitions) improve plant growth. PGPRs also stimulate the induced systemic resistance (ISR) in plants, thereby increasing the resistance of plants against various pathogens by jasmonic acid (JA) and ethylene (ET) signaling pathways. The ISR was described for different PGPRs species, including Pseudomonas spp., Bacillus spp., and Burkholderia spp. The decrease in disease severity in various host plants has been described by numerous researches. This chapter focuses on the potential of PGPRs as suitable biocontrol agents and the mechanisms involved in sustainable plant disease management. © 2024 Elsevier Inc. All rights reserved.