Multifunctional antagonistic mechanisms of the soybean nodule endophyte Pseudomonas sp. JDE115 against Agroathelia rolfsii

Soil-borne pathogens such as southern blight, caused by Agroathelia rolfsii , threaten soybean production and are difficult to control with chemicals. To reduce reliance on fungicides, we evaluated the soybean nodule endophyte Pseudomonas sp. JDE115 as a sustainable biocontrol agent. In vitro and greenhouse assays showed strong suppression of fungal hyphae and sclerotia, with treated plants remaining symptom-free. Scanning electron microscopy revealed collapsed sclerotia, while functional assays confirmed siderophore, protease, and hydrogen cyanide production. Gas chromatography–mass spectrometry identified volatile organic compounds, including 1-undecene and dimethyl disulfide, as key antifungal metabolites. These findings highlight JDE115 as a multifunctional antagonist with potential integration into integrated pest management programs, supporting reduced chemical inputs, soil health, and resilient agroecosystems.