The chapter discusses the mechanisms by which non-pathogenic soil-borne microorganisms, known as plant growth-promoting rhizobacteria (PGPR), can enhance plant growth and suppress diseases. PGPR promote plant growth through improved nutrient acquisition or hormonal stimulation, while they suppress diseases through microbial antagonism or induction of systemic resistance (ISR) in plants. The chapter highlights that ISR confers enhanced resistance to various pathogens and can be either local or systemic, depending on the interaction between the inducing rhizobacterium and the challenging pathogen. It also explores the signaling pathways involved in ISR, which are distinct from those of pathogen-induced systemic acquired resistance (SAR). The chapter further examines the role of plant hormones such as jasmonic acid and salicylic acid in these resistance mechanisms and the interaction between PGPR and plants, including the recognition of bacterial determinants by plant receptors. Additionally, it discusses the impact of root exudates and quorum sensing on the interaction between plants and PGPR, and the potential for PGPR to alter plant secondary metabolism and defense responses. The chapter concludes by reviewing the molecular and genetic mechanisms underlying the induction of ISR by PGPR and the specificity of these interactions across different plant species.The chapter discusses the mechanisms by which non-pathogenic soil-borne microorganisms, known as plant growth-promoting rhizobacteria (PGPR), can enhance plant growth and suppress diseases. PGPR promote plant growth through improved nutrient acquisition or hormonal stimulation, while they suppress diseases through microbial antagonism or induction of systemic resistance (ISR) in plants. The chapter highlights that ISR confers enhanced resistance to various pathogens and can be either local or systemic, depending on the interaction between the inducing rhizobacterium and the challenging pathogen. It also explores the signaling pathways involved in ISR, which are distinct from those of pathogen-induced systemic acquired resistance (SAR). The chapter further examines the role of plant hormones such as jasmonic acid and salicylic acid in these resistance mechanisms and the interaction between PGPR and plants, including the recognition of bacterial determinants by plant receptors. Additionally, it discusses the impact of root exudates and quorum sensing on the interaction between plants and PGPR, and the potential for PGPR to alter plant secondary metabolism and defense responses. The chapter concludes by reviewing the molecular and genetic mechanisms underlying the induction of ISR by PGPR and the specificity of these interactions across different plant species.