Filamentous fungi have many secondary metabolism genes and produce a wide variety of secondary metabolites with complex and unique structures. However, the role of most secondary metabolites remains unclear. Moreover, most fungal secondary metabolism genes are silent or poorly expressed under laboratory conditions and are difficult to utilize. Pyricularia oryzae, the causal pathogen of rice blast disease, is a well-characterized plant pathogenic fungus. P. oryzae also has a large number of secondary metabolism genes and appears to be a suitable organism for analyzing secondary metabolites. However, in case of this fungus, biosynthetic genes for only four groups of secondary metabolites have been well characterized. Among two of the four groups of secondary metabolites, biosynthetic genes were identified by activating secondary metabolism. These secondary metabolites include melanin, a polyketide compound required for rice infection; tenuazonic acid, a well-known mycotoxin produced by various plant pathogenic fungi and biosynthesized by a unique nonribosomal peptide synthetase–polyketide synthase hybrid enzyme; nectriapyrones, antibacterial polyketide compounds produced mainly by symbiotic fungi, including plant pathogens and endophytes, and pyriculols, phytotoxic polyketide compounds. This review mainly focuses on the biosynthesis and biological functions of the four groups of P. oryzae secondary metabolites.

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稻瘟病菌稻瘟病菌次生代谢产物的生物合成及生物学功能

丝状真菌具有许多次生代谢基因，产生种类繁多、结构复杂、独特的次生代谢产物。然而，大多数次生代谢物的作用仍不清楚。此外，大多数真菌次生代谢基因在实验室条件下是沉默的或表达不良，难以利用。稻瘟病菌是稻瘟病的致病菌，是一种特征明确的植物病原真菌。米曲霉还具有大量次生代谢基因，似乎是分析次生代谢物的合适生物体。然而，就这种真菌而言，仅四组次生代谢物的生物合成基因得到了很好的表征。在四组次生代谢物中的两组中，通过激活次生代谢来鉴定生物合成基因。这些次生代谢物包括黑色素，一种水稻感染所需的聚酮化合物；tenuazonic Acid，一种众所周知的霉菌毒素，由多种植物病原真菌产生，由独特的非核糖体肽合成酶-聚酮合酶杂合酶生​​物合成；Nectriapyrones，主要由共生真菌（包括植物病原体和内生菌）产生的抗菌聚酮化合物，以及吡啶酮，植物毒性聚酮化合物。本文主要对四类米稻次生代谢产物的生物合成和生物学功能进行综述。