First Report of Zearalenone Production by Talaromyces Isolated from Bidens pilosa Using LC-q-TOF-MS and Molecular Networking

Green leafy vegetables like Bidens pilosa are valuable sources of nutraceuticals worldwide. However, due to minimal human intervention, these wild-growing plants can be exposed to pollution and pathogenic microorganisms including endophytic fungi that may produce toxic secondary metabolites. Herein, metabolic profiling of methanolic extracts containing endophytic fungi isolated from B. pilosa was conducted using LC-q-TOF-MS and molecular networking. One of the fungi was found to produce a mycotoxin called zearalenone, which is known to be a reproductive system disruptor. The presence of zearalenone was further confirmed using an authentic standard and a series of tandem mass spectrometry approaches. ITS sequencing identified the zearalenone-producing endophytic fungus as Talaromyces, showing sequence similarity to various species within this genus. Findings of this study highlight the importance of exercising caution when consuming green leafy vegetables, as they may contain toxic compounds produced by endophytic fungi, despite being easily accessible and rich in valuable nutraceuticals.