A Novel Endophytic Fungus R-423 for the Control of Root Rot in Pigeon Pea as Reflected by the Alleviation of Reactive Oxygen Species-Mediated Host Defense Responses.

root rot is a devastating fungal disease that causes significant yield losses in legume crops. A novel endophytic fungus R-423 isolated from pigeon pea had a significant antagonistic capacity against . R-423 extracts could inhibit growth and cause it to die. Four host-specific and 15 genus-specific metabolites were identified as potential antimicrobial compounds. R-423's inoculation effectively controlled root rot in pigeon pea seedlings and promoted root growth. Co-inoculation of R-423 and reduced the levels of oxidative stress, pathogenesis- and biosynthesis-related gene expression, and phenolic compound accumulation in roots compared to those infected with , confirming that reactive oxygen species-mediated host defense responses were alleviated due to the effective control of by R-423. Overall, R-423 was a promising biocontrol agent against root rot in legume crops.