Figure 2.

Hypothetical model of the regulation of fungal growth and toxin synthesis signal transmission in Aspergillus by oxylipins. Highlighted in yellow and blue are the fungal and food oxylipin biosynthetic enzymes. Polyunsaturated fatty acid substrates in food are processed by fungal-secreted lipoxygenase for oxylipin production. Fungi can sense and exploit oxylipins from food substrates to regulate GPCR-, cAMP/PKA- and Ppo-mediated growth, sporulation, and mycotoxin production. In these processes, the light sensor protein VeA and the protein degradation machinery COP9 are involved in the regulation of the PPO genes. Oxylipins regulate sporulation through cleistothecial (NsdD)- and conidiophore (BrlA)-specific transcription factors, as well as secondary metabolism (e.g., sterigmatocystin) through AflR.