Microenvironmental interplay predominated by beneficial Aspergillus abates fungal pathogen incidence in paddy environment

Rice fungal pathogens-responsible severe rice yield loss and biotoxin contamination cause increasing concerns on environmental safety and public health. In paddy environment, we observed that the asymptomatic rice phyllosphere microenvironment was dominated by an indigenous fungus, Aspergillus cvjetkovicii, which positively correlated with alleviated incidence of Magnaporthe oryzae, one of the most aggressive plant pathogens. Through the comparative metabolic profiling for rice phyllosphere microenvironment, two metabolites were assigned as exclusively-enriched metabolic markers in asymptomatic phyllosphere and increased remarkably in a population-dependent manner with A. cvjetkovicii. These two metabolites evidenced to be produced by A. cvjetkovicii in either phyllosphere microenvironment or artificial media, were purified and identified as 2(3H)-benzofuranone and azulene, respectively by GC-QqQ-MS/MS and NMR analyses. Combining with bioassay analysis in vivo and in vitro, we found 2(3H)-benzofuranone an...