Lipid signals in the interaction between mycotoxigenic fungi and their hosts. The case of lipid-derived BVOCS in Aspergillus flavus-maize interaction

Lipid molecules are gaining momentum as signals exchanged by interacting organisms during pathogenic and/or symbiotic deals. Some class of lipids, especially those over-represented in the interaction interfaces actively drive the fate of plantmicroorganism interactions. Notably, lipid compounds may reprogram the transcriptome of the pathogen as well as of the host, leading to defence responses such as programmed cell death in plants or mycotoxin synthesis in the pathogen. In relation to this, host-cuticle components such as sphingolipids and oxylipins may contribute to drive host-pathogen interactions. According to available studies, sphingolipids are involved in signalling pathways that promote hypersensitive response and associated programmed cell death in plants whilst some phyto-oxylipins may affect virulence and the production of secondary metabolites in pathogenic fungi. Plant and fungi communicate by the mean of biogenic volatile organic compounds. Several of these are by-products of fatty acid oxidation also because of enhanced respiration consequent to fungal contamination. In our study, we depict the changes in BVOCs profile of maize kernels challenged with A. flavus, suggesting a potential role in the molecular cross-talk that these two competing organisms entertain during their interaction.