Understanding plant bacterial wilt: pathogen diversity, ecological interactions, and management challenges

Microbial Interactions and Their Impact on Plant Bacterial Wilt Pathogen-Host Dynamics. Graphical illustrates the complex microbial interactions in plant bacterial wilt (PBW), focusing on competition, antagonism, and synergy. The interactions between pathogens and other microbes impact host immunity, pathogen growth, and disease outcomes through mechanisms like competitive exclusion, iron sequestration, biofilm formation, and co-infection. Competitive and antagonistic interactions often suppress pathogens like R. solanacearum by secreting antibacterial compounds or altering the microenvironment, reducing disease incidence. Conversely, synergistic interactions and co-infections worsen disease by enhancing pathogen virulence, facilitating horizontal gene transfer, and promoting mutagen production, increasing resistance genes, particularly between R. solanacearum and co-infecting bacteria. These interactions affect host health and drive pathogen evolution. Pa (primary pathogens), E-Pa (emerging pathogens), Co-Pa (co-infecting bacteria), PCo-Pa (potential co-infecting bacteria), PGPB (plant growth-promoting bacteria), P-PGPB (potential plant growth-promoting bacteria), and U-func (bacteria with unknown functions). • PBW is driven by Ralstonia solanacearum and synergistic pathogens under dysbiosis. • Microbial ecology modulates PBW development through competition, antagonism, and synergism. • Co-infection mechanisms involve sequential contact, colonization, and proliferation stages. • Quorum sensing regulates virulence factors during multi-pathogen PBW infections. • Multi-omics approaches facilitate sustainable strategies for PBW management. Plant bacterial wilt (PBW) represents a globally significant soil-borne disease, notable for its diverse causal pathogens and complex pathogenesis, which pose substantial challenges to agricultural production due to its rapid onset and difficulty in management. This review systematically explores the microbial ecology of PBW, focusing on four critical dimensions: (1) the impact of microbial ecology on disease progression, with particular attention to pathogen diversity and ecological interactions; (2) microbial competition, antagonism, and synergy; (3) the mechanisms of co-infection, encompassing the stages of contact, colonization, and proliferation; and (4) the regulatory role of quorum sensing (QS) in co-infection processes. A comprehensive review of the existing literature reveals that PBW is a multifaceted disease system primarily driven by Ralstonia solanacearum and its synergistic pathogens, intricately linked to plant microbial dysbiosis. Furthermore, we synthesize key research findings, address current challenges and limitations, and propose future research and application directions to inform sustainable strategies for managing PBW effectively.