Biosynthesis Regulation of Secondary Metabolite Production in Fusarium Fungi

<i>Fusarium</i> fungi are prolific producers of a wide array of structurally and functionally diverse secondary metabolites (SMs), ranging from harmful mycotoxins to beneficial phytohormones and medicines. Many of these compounds show significant promise for use as agrochemicals, pharmaceuticals and food additives. The biosynthesis of these SMs in <i>Fusarium</i> fungi is strictly regulated by a complex network composed of various regulatory components. This review highlights recent advances in understanding how secondary metabolism in <i>Fusarium</i> fungi is regulated at various levels, particularly through the regulation of environmental factors (e.g., light, temperature, pH, carbon, and nitrogen sources), global and pathway-specific transcriptional factors (e.g., LaeA, LaeB, AreA, Tri6, and ZEB2), epigenetic modifications (e.g., histone acetylation and methylation, DNA and RNA modifications), and signal transduction pathways (e.g., cAMP, TOR, and MAPK pathways). Furthermore, the biological significances and potential applications of some metabolites (e.g., beauvericin, bikaverin, gibberellins, fumonisins, fusaric acid, and trichothecenes) produced by <i>Fusarium</i> fungi were discussed. Biosynthesis regulation on SM production offers a powerful approach to either unlock silent or cryptic biosynthetic gene clusters (BGCs) for the discovery of new SMs, to boost the yiled of low-abundance beneficial metabolites, or suppress specific BGCs to eliminate the production of toxic compounds in <i>Fusarium</i> fungi.