黑色素生物合成是病原真菌抵御环境胁迫的重要生存策略。真菌通过1,8-二羟基萘酚和多巴胺途径合成黑色素，但桦褐孔菌水溶性黑色素合成不受这两个途径的专化性抑制剂熊果苷或三环唑抑制。前期研究发现桦褐孔菌一杂合的非核糖体肽合成酶-聚酮合酶基因(nrps-pks)表达产物与其水溶性黑色素相似，且该nrps-pks与蛋白激酶、二肽酶及溶血素共调蛋白等10个基因形成基因簇，但尚无该类黑色素合成途径及生物学研究的信息资料。本项目拟以构巢曲霉遗传操作体系，系统开展以下研究：1) 借助基因敲除技术分析nrps-pks结构域、产物组成单元及化学结构；2) 采用基因簇克隆技术探明nrps-pks基因簇激活机制；3)利用原核表达技术阐明nrps-pks表达产物结构修饰，界定该类真菌黑色素合成的新途径，从分子水平揭示真菌黑色素合成新途径的表达调控机制，为真菌抵御环境胁迫的生存策略提供新的理论依据。

Melanin biosynthesis is the important survival strategy for pathogenic fungi to resist environmental stress. Fungal melanins have been thought to be the products of 1,8-dihydroxylnaphthalene (DHN) and dopamine (DOPA) pathway. However, biosynthesis of water-soluble melanin (WSM) by basidiomycetous fungus Inonotus obliquus cannot be inhibited by the pathway-specific inhibitors tricyclazole or arbutin. Previous work showed that physico-chemical properties of WSM by I. obliquus is very similar to the product of a gene encoding hybrid NRPS-PKS from the fungus. Moreover, this nrps-pks formed a gene cluster with other 10 genes including those encoding protein kinase (cluster activation related),dipetidase (structure modification related) and haemolysin co-regulated protein (transmenbrane transportation related).But little is known about the biosynthetic pathway of this WSM and the information of its biological studies.Taking advantage of the toolbox of Aspergillus nidulans, this project is designed to study the following questions: 1) Analyzing domain functions of the nrps-pks and its product monomer structure with the aid of gene knock-out methodologies; 2) Searching for the machinery on activating NRP-PK melanin biosynthetic gene cluster by cloning the cluster to A. nidulans with Red/ET recombineering kit; 3) Elucidating structure modification of initially expressed product of nrps-pks using techniques of prokaryotic expression for catergorizing the biosynthetic pathway of this class of melanin, and further illuminating the mechanisms on transmenbrane transportation of the NRP-PK melanin.The results of this project will reveal a novel pathway for the biosynthesis of fungal melain, and provide new theory for the fungal survial strategy against environmental stress.