中文摘要：

黄曲霉菌（Aspergillus flavus）是一种腐生型好氧真菌，其次级代谢产生的黄曲霉毒素（Aflatoxin，AFT）是一种强致癌性剧毒物质。黄曲霉菌侵染农作物导致相关农产品黄曲霉毒素的污染，危及食品安全及人和动物的健康。黄曲霉菌有8条染色体，基因组大小约37 Mb，含有13 000多个功能基因，55个次级代谢基因簇，其中只明确了AFT、环匹阿尼酸（Cyclopiazonic acid，CPA）和黄曲霉震颤素（Aflatrem）3个次级代谢基因簇的特征。次级代谢基因簇的表达受不同环境条件、次级代谢调控因子、酶活性、复杂的脂氧合物转导信号及群体密度效应的调控。LaeA和VeA是抑制AFT、CPA和黄曲霉震颤素等真菌毒素生物合成的次级代谢调控因子，抑制加氧酶类（Ppo和Lox）的表达则能促进真菌毒素的合成，而其氧化产物（脂氧合物）则是真菌-寄主互作的重要信号分子。群体密度和水解酶类也影响黄曲霉菌的次级代谢，群体密度高能降低黄曲霉毒素的生成量而增加分生孢子的形成；α-淀粉酶、果胶酶、蛋白酶等酶活性的改变可以影响黄曲霉菌分生孢子萌发、菌丝生长，以及真菌毒素的次级代谢。本文系统评述了黄曲霉主要真菌毒素的次级代谢与调控的研究进展。此外，对黄曲霉次级代谢物的研究也做了进一步的评述和讨论。

英文摘要：

Aflatoxin （AFT） contamination caused by Aspergillus flavus, a saprophytic aerobic fungus, in several crops such as peanut, maize and cottonseed is considered as the most serious factor influencing food safety concerning animal and human health worldwide. Whole genome sequences of A. flavus have been released and the genome size is about 37 Mb on 8 chromosomes encoding over 13 000 functional genes. In the whole genome sequences of A. flavus （NRRL3357）, 55 putative secondary metabolite clusters have been identified based on backbone enzyme gene analysis by SMURF, and only three secondry metabolite clusters including AFT, cyclopiazonic acid （CPA） and aflatrem have been characterized. The above three secondary metabolite clusters are regulated by different environmental factors, secondary metabolite regulators, enzymatic activity, oxylipin and quorum sensing. AFT, CPA and aflatrem biosynthesis are inhibited by the global regulators, LaeA and VeA, in secondary metabolism. A family of oxylipin-producing oxygenases and their products encoded by ppo and lox can regulate sclerotia and conidia production and secondary metabolism in A. flavus. The profile of secondary metabolites could be influenced by variation of fungi density because higher fungi density will induce higher sporulation with decreased AFT. Most strains of A. flavus can produce numerous hydrolytic enzymes including α-amylases, pectinases, proteases, and lipases, which are believed to be important for fungal infection and virulence to host tissue. Further research on regulation of secondary metabolism and mycotoxins produced in A. flavus are also discussed.