Abstract: Patulin (PAT) is a toxic secondary metabolite produced by filamentous fungi such as Penicillium, Aspergillus and Byssochlamys, which poses a serious threat to human health. This article describes the patulin biosynthesis pathway, and its related genes and encoded enzymes as well as molecular regulation. Biosynthesis of PAT is determined by the patulin gene cluster (Pat) including 15 genes (PatA through PatO), which encodes catalytic enzymes, transcription factors and transporters involved in the biosynthesis pathway. The reaction starts from one molecule of acetyl-CoA and three molecules of malonyl-CoA to synthesize 6-methylsalicylic acid, which is decarboxylated and hydroxylated into gentisaldehyde, and then converted into isoepoxydon, phyllodin, E-ascladiol, and eventually patulin by a series of reactions. The biosynthetic pathway is not only regulated by the key genes encoding the catalytic enzymes, the specific transcriptional regulator (PatL), the global regulatory factors (LaeA, CreA and AreA), the pH-dependent regulatory factor (PacC), and the light regulatory factors (VeA and VelB), but also influenced by host factors. The aim of this paper is to provide a theoretical basis for the control and removal of patulin in cereals, vegetables, fruits and their products.

Key words: patulin; Penicillium expansum; mycotoxins; biosynthetic pathway; molecular regulation