Synergistic interplay of microbial probiotics in rice rhizosphere: A sustainable strategy for bacterial blight management through microbiome engineering

This review explores the potential of microbial endophytes as biocontrol agents against bacterial leaf blight in rice caused by Xanthomonas oryzae pv. oryzae (Xoo). Endophytic bacteria viz., Bacillus spp., Streptomyces spp., and Pseudomonas spp. exists around, on and inside rice rhizospheres and tissues exhibit significant biocontrol and plant growth-promoting properties. These microorganisms produce vital metabolites such as siderophores, indole acetic acid (IAA), and phosphatases, which aid in suppressing bacterial blight and enhancing plant health. Studies have shown that Bacillus amyloliquefaciens BAS23 and Streptomyces rimosus AUDT-502 are particularly effective in reducing disease severity and improving growth metrics in greenhouse and field trials. Phosphatesolubilizing bacteria also play a crucial role by enhancing phosphorus availability and suppressing bacterial blight. Despite the promising results, several challenges, such as variability in effectiveness due to environmental factors and the need for scalable production and application methods, still require investigation. The successful integration of microbial strains inoculants with proven probiotics potential i.e., microbiome engineering to establish synthetic microbial consortia into agricultural practices requires addressing problems related to strain selection, production, and deployment. Understanding the complex interactions between endophytes, rice plants, and bacterial blight pathogen is critical for optimizing biocontrol strategies. Encapsulation and genetic transformation of these core microbiota (plant probiotics) will be the innovative strategy to enhance their resilience to environmental functioning and viability towards long-term sustainability.