关键词: 真菌毒素, 镰刀菌, 单端孢霉烯族毒素, 生物合成途径, 食品安全

Abstract: Trichothecenes are a large family of toxic secondary metabolites mainly produced by the Fusarium genus, which threaten human and animal health. In this article, the genes, pathways, enzymes, and regulatory mechanisms for the biosynthesis of thrichothecenes are summarized. The biosynthetic enzymes and direct regulatory proteins of trichothecenes are encoded by at least 3 gene clusters: Tri5, Tri1-Tir16 and Tri101, including Tri5 encoding trichodiene synthase, Tri4, Tri11 and Tri13 encoding cytochrome P450 monooxygenases, Tri6 and Tri10 encoding a regulatory protein, Tri7, Tri3, Tri16 and Tri101 encoding acetyltransferases, Tri8 encoding deacetylase, Tri1 encoding hydroxylase, and Tri12 encoding a trichothecene efflux pump. The biosynthesis of trichothecenes begins with to the cyclization of trans-farnesyl pyrophosphate to form trichodiene, followed by oxygenation, isomerization, cyclation and esterification to eventually form toxins with different structures. The types of toxins mainly determined by metabolic pathways and genetic differences. The biosynthetic pathways are regulated by not only specific transcription factors such as TRI6 and TRI10 but also global regulatory factors such as Pac and VeA related to the external environment. This review aims to provide a theoretical basis for the prevention, control and detoxification of mycotoxins in food and feed.

Key words: mycotoxins, Fusarium, trichothecenes, biosynthetic pathway, food safety