Identification of a new phomoxanthone antibiotic from Phomopsis longicolla and its antimicrobial correlation with other metabolites during fermentation

摘要

Agricultural production incurs substantial losses mainly due to plant diseases all over the world-every year. Rice, the most important crop, provides food for over half of the world's human population, but many bacterial and fungal diseases affect rice plants, reducing the yield. Bacterial leaf blight (BLB) in particular is a major rice disease from an economic point of view in irrigated and rain-fed lowland ecosystems. Xanthomonas oryzae pv. oryzae (Xoo), a member of the gammaproteobacteria, is a major pathogen causing BLB of rice. Xoo enters rice leaves through water pores or wounds and moves systemically by invading the xylem, causing the disease known as bacterial blight. The last decade has seen a dramatic advancement in our understanding of the molecular basis of the rice/Xoo interaction with research on rice resistance and many virulence-related genes. In previous research, we reported the antimicrobial activity of secondary metabolites from Phomopsis longicolla S1B4 against Xoo and other pathogenic microorganisms. Phomopsis are endophytic fungi that are rich sources of secondary metabolites including phomopsins, hexapeptides containing many unnatural amino acids (P. leptostromiformis), phomopsolides, alpha beta-unsaturated b-lactones (P. oblonga), dicerandrols, xanthone dimers (P. longicolla), phomodiol, phomopsichalasin, phomoxanthones, phomopsidin, phomol, mycoepoxydienes, phomoenamide and phomonitroester {Phomopsis sp.).