Biocontrol of Colletotrichum brevisporum in soybean using a new genistein-producing Paecilomyces strain

Colletotrichum brevisporum is a hazardous fungal pathogen that can cause anthracnose disease in several crops. In this study, Paecilomyces maximus NJC01 was isolated from C. brevisporum-infected soybean plants, and identified by ITS and TUB2 sequencing and morphological analysis. Interestingly, NJC01 inhibited the mycelial growth of plant fungal pathogens C. brevisporum, Sclerotinia sclerotiorum, Ceratocystis fimbriata and Valsa pyri. NJC01 showed various antifungal mechanisms against C. brevisporum, including competition for space and nutrients and the production of secondary metabolite genistein, which was detected at 91.8 mu g/mL in the culture medium. NJC01 could colonize wounds in soybean pods, maintained its population in the inoculation site, and did not cause necrotic lesions. Combination of 1 x 10(8 )cells/mL NJC01 and heat treatment reduced C. brevisporum lesions by 45%. The first biocontrol strategy for the management of C. brevisporum is reported in this study. This study provides new insights on the use of Paecilomyces species for the biocontrol of anthracnose disease.