Protection of melon against Fusarium wilt-root knot nematode complex by endophytic fungi Penicillium brefeldianum HS-1

Colonization of plants by particular endophytic fungi can provide plants with improved defenses toward pests and pathogens. In this study, an endophytic fungi, strain HS-1, was isolated from the root of Cucumis melo L. and characterized as Penicillium brefeldianum. The crude metabolites showed great antifungal and antinematodal activities in vitro and the major bioactive component was purified and identified as brefeldin A (BFA). BFA had been reported as active metabolite against pathogenic fungi and nematodes, however, no research using BFA-producing fungi as a biocontrol agent was reported before. For this purpose, the protect effects of strain HS-1 against Fusarium wilt-root knot nematode complex was conducted in vivo. Results showed that strain HS-1 pre-inoculation significantly reduced the disease severity and gall numbers after 4weeks of challenging by Fusarium pathogen, Fusarium oxysporum f. sp. Melonis and root-knot nematodes, Meloidogyne incognita Chitwood. The population of strain HS-1 on Cucumis melo L. dramatically increased after 4weeks of challenging along with high accumulation of BFA in the roots of the host, indicating an antibiosis for competitor deterrence and host plant protection.