P-343 - Influence of precision oriented peptides - poultry feather-derived biostimulants on crop microbiome and microbial quorum sensing systems

Microbial communities are vital for plant health, growth, and productivity, with the rhizosphere as a hub for microbial interactions. Quorum sensing (QS), a microbial communication system, regulates pathogenesis and symbiosis. Precision-Oriented Peptides (POPs), derived from poultry feathers via thermodynamic hydrolysis, enhance crop health, stress tolerance, and disease resistance. Here, we compare POPs and chemical fertilizers on rice and maize rhizosphere microbiomes while also assessing the role of POP in QS modulation. POPs did not significantly affect microbial abundance or diversity but altered community composition. Compared to chemical fertilizers, POPs reduced fungal pathogens such as Fusarium and Cladosporium in rice and maize, potentially lowering bakanae disease and grain infections, while promoting beneficial microbes (Bacillus and Trichoderma). In maize, POPs suppressed pathogens (Fusarium, Curvularia, Cladosporium) and increased Bacillus, fostering a healthier microbiome. POPs also influenced nitrogen- and sulfur-metabolizing microbes, enhancing plant growth, nutrient uptake, and yield. The results demonstrated that POPs inhibited violacein production in Chromobacterium violaceum, regulated by the AHL QS system, without affecting bacterial growth. POPs also disrupted QS in Xanthomonas campestris and promoted biofilm formation in Bacillus subtilis, indicating QS modulation in rhizosphere microbes. In summary, POPs modulate the rhizosphere microbiome by promoting beneficial microbes, and enhancing plant health, resilience, and disease resistance.