Georgianna D Ryan, Payne Gary A
Department of Plant Pathology, North Carolina State University, 851 Main Campus, Dr. Partners III Suite 267, Raleigh, NC 27606, Campus Box 7244, USA.
Fungal Genet Biol. 2009 Feb;46(2):113-25. doi: 10.1016/j.fgb.2008.10.011. Epub 2008 Nov 5.
Aflatoxins are notorious toxic secondary metabolites known for their impacts on human and animal health, and their effects on the marketability of key grain and nut crops. Understanding aflatoxin biosynthesis is the focus of a large and diverse research community. Concerted efforts by this community have led not only to a well-characterized biosynthetic pathway, but also to the discovery of novel regulatory mechanisms. Common to secondary metabolism is the clustering of biosynthetic genes and their regulation by pathway specific as well as global regulators. Recent data show that arrangement of secondary metabolite genes in clusters may allow for an important global regulation of secondary metabolism based on physical location along the chromosome. Available genomic and proteomic tools are now allowing us to examine aflatoxin biosynthesis more broadly and to put its regulation in context with fungal development and fungal ecology. This review covers our current understanding of the biosynthesis and regulation of aflatoxin and highlights new and emerging information garnered from structural and functional genomics. The focus of this review will be on studies in Aspergillus flavus and Aspergillus parasiticus, the two agronomically important species that produce aflatoxin. Also covered will be the important contributions gained by studies on production of the aflatoxin precursor sterigmatocystin in Aspergillus nidulans.
黄曲霉毒素是臭名昭著的有毒次生代谢产物，因其对人类和动物健康的影响以及对主要谷物和坚果作物市场适销性的影响而闻名。了解黄曲霉毒素的生物合成是众多不同研究群体的重点。该群体的共同努力不仅带来了一个特征明确的生物合成途径，还促成了新调控机制的发现。次生代谢的一个共同特点是生物合成基因成簇排列，且受途径特异性调控因子以及全局调控因子的调节。最近的数据表明，次生代谢产物基因在簇中的排列可能允许基于沿染色体的物理位置对次生代谢进行重要的全局调控。现有的基因组学和蛋白质组学工具使我们能够更广泛地研究黄曲霉毒素的生物合成，并将其调控与真菌发育和真菌生态学联系起来。本综述涵盖了我们目前对黄曲霉毒素生物合成和调控的理解，并突出了从结构和功能基因组学中获得的新的和正在出现的信息。本综述的重点将是对黄曲霉和寄生曲霉这两种产生黄曲霉毒素的重要农业相关物种的研究。还将涵盖对构巢曲霉中黄曲霉毒素前体柄曲霉素产生的研究所取得的重要贡献。
