Lipo-chitooligosaccharides (LCOs) are signaling molecules produced by rhizobial bacteria that trigger the nodulation process in legumes, and by some fungi that also establish symbiotic relationships with plants, notably the arbuscular and ecto mycorrhizal fungi. Here, we show that many other fungi also produce LCOs. We tested 59 species representing most fungal phyla, and found that 53 species produce LCOs that can be detected by functional assays and/or by mass spectroscopy. LCO treatment affects spore germination, branching of hyphae, pseudohyphal growth, and transcription in non-symbiotic fungi from the Ascomycete and Basidiomycete phyla. Our findings suggest that LCO production is common among fungi, and LCOs may function as signals regulating fungal growth and development.

The plant pathogenic fungus Penicillium expansum is a major concern of the global food industry due to its wide occurrence and ability to produce various mycotoxins, of which the most significant is patulin. Relatively less highlighted in the literature, in comparison with the other food-borne mycotoxins, patulin is one of the main factors in economic losses of vegetables and fruits. Otherwise, patulin is a health hazard which results in both short-term and long-term risks. This review includes knowledge on the biosynthetic mechanisms used for secondary metabolite production in P. expansum, with special emphasis on patulin biosynthesis. The abiotic factors triggering the production of patulin and the strategies developed to reduce or prevent the contamination by this mycotoxin are comprehensively discussed. The database presented in this review would be useful for the prioritization and development of future research.