Deciphering metabolomic signatures of drought adaptation in groundnut triggered by encapsulated microbial biostimulant

Microbial biostimulants enhance crop resilience to drought and promote sustainable agricultural productivity. The present research aimed to elucidate the metabolomic variations induced by encapsulated microbial biostimulants for drought tolerance in groundnut. Two rhizobacterial strains, Acinetobacter calcoaceticus AC12 and Bacillus amyloliquefaciens BA13, were functionally tested for plant growth promoting attributes and osmolyte production under osmotic stress. AC12 and BA13, as consortium, were encapsulated using sodium alginate and chitosan to formulate a plant-growth-promoting rhizobacteria (PGPR)-based microbial biostimulant. The encapsulated microcapsules were characterized by SEM, FTIR, and other physiochemical properties. The results of a field trial demonstrated that the encapsulated microbial biostimulant had a significant ( p < 0.05) impact on the physiological, biochemical, and yield attributes of groundnut under drought. Groundnut seed metabolomic analysis identified 52 altered metabolites, including sugars, fatty acids, and amino acids. Partial least square discriminant analysis and heat map identified potential biomarker metabolites. A pathway enrichment analysis revealed that inoculation of encapsulated biostimulants significantly altered 25 metabolic pathways under water deficit conditions. By deciphering key metabolomic shifts, the study provides insights on biostimulant-based drought endurance and lays a foundation for developing new biostimulant products with encapsulation technology to enhance global food production and nutrition.