Plant Growth-Promoting Microorganisms as agents of  biological control: Mechanisms and perspectives for  sustainable plant protection

Orsolya Kedves; Dóra Balázs; Jelena Živančev; Igor Antić; Nataša Đurišić-Mladenović; Rita Büchner; András Szekeres; Tamás Marik; Csaba Vágvölgyi; László Kredics

doi:10.14232/abs.2026.1.11-22

Authors

Orsolya Kedves University of Szeged , Department of Biotechnology and Microbiology https://orcid.org/0000-0002-2184-9607
Dóra Balázs University of Szeged , Department of Biotechnology and Microbiology
Jelena Živančev University of Novi Sad https://orcid.org/0000-0002-2568-2189
Igor Antić University of Novi Sad https://orcid.org/0000-0003-3246-5825
Nataša Đurišić-Mladenović University of Szeged , Department of Biotechnology and Microbiology https://orcid.org/0000-0002-5203-6051
Rita Büchner University of Szeged , Department of Biotechnology and Microbiology https://orcid.org/0000-0002-7639-5163
András Szekeres University of Szeged , Department of Biotechnology and Microbiology https://orcid.org/0000-0003-1651-4623
Tamás Marik University of Szeged , Department of Biotechnology and Microbiology https://orcid.org/0000-0002-0434-5685
Csaba Vágvölgyi University of Szeged , Department of Biotechnology and Microbiology https://orcid.org/0000-0003-0009-7773
László Kredics University of Szeged , Department of Biotechnology and Microbiology https://orcid.org/0000-0002-8837-3973

DOI:

https://doi.org/10.14232/abs.2026.1.11-22

Keywords:

biological control, induced systemic resistance, PGPM, PGPB, PGPF, plant health

Abstract

Plant growth-promoting microorganisms (PGPM), including plant growth-promoting bacteria (PGPB) and plant growth-promoting fungi (PGPF), can improve plant performance while simultaneously suppressing plant pathogens. Most PGPM colonize the rhizosphere, and some are also able to establish endophytic populations within plant tissues, where they contribute to plant health through direct antagonism, induced systemic resistance, improved nutrient acquisition, and phytohormone-related effects. These properties make PGPM attractive alternatives or complements to conventional pesticides in sustainable plant protection. This mini-review summarizes the principal mechanisms by which PGPM suppress pathogens, with particular emphasis on antimicrobial secondary metabolites, siderophore production, extracellular hydrolytic enzymes, mycoparasitism, mycophagy, and induced systemic resistance. In addition, nutrient mobilization and microbial phytohormone production are discussed as indirect but important contributors to disease reduction and plant vigor. Overall, PGPM-based approaches provide a multifunctional framework for sustainable plant protection by integrating direct pathogen suppression with improved plant performance and defense.