Melanisation has been considered to be an important virulence factor of Fonsecaea monophora. However, the biosynthetic mechanisms of melanisation remain unknown. We therefore used next generation sequencing technology to investigate the transcriptome and digital gene expression data, which are valuable resources to better understand the molecular and biological mechanisms regulating melanisation in F. monophora. We performed de novo transcriptome assembly and digital gene expression (DGE) profiling analyses of parent (CBS 122845) and albino (CBS 125194) strains using the Illumina RNA-seq system. A total of 17 352 annotated unigenes were found by BLAST search of NR, Swiss-Prot, Gene Ontology, Clusters of Orthologous Groups and Kyoto Encyclopedia of Genes and Genomes (KEGG) (E-value <1e‒5). A total of 2 283 unigenes were judged to be the differentially expressed between the two genotypes. We identified most of the genes coding for key enzymes involved in melanin biosynthesis pathways, including polyketide synthase (pks), multicopper oxidase (mco), laccase, tyrosinase and homogentisate 1,2-dioxygenase (hmgA). DEG analysis showed extensive down-regulation of key genes in the DHN pathway, while up-regulation was noted in the DOPA pathway of the albino mutant. The transcript levels of partial genes were confirmed by real time RT-PCR, while the crucial role of key enzymes was confirmed by either inhibitor or substrate tests in vitro. Meanwhile, numbers of genes involved in light sensing, cell wall synthesis, morphology and environmental stress were identified in the transcriptome of F. monophora. In addition, 3 353 SSRs (Simple Sequence Repeats) markers were identified from 21 600 consensus sequences. Blocking of the DNH pathway is the most likely reason of melanin deficiency in the albino strain, while the production of pheomelanin and pyomelanin were probably regulated by unknown transcription factors on upstream of both pathways. Most of genes involved in environmental tolerance to oxidants, irradiation and extreme temperatures were also assembled and annotated in transcriptomes of F. monophora. In addition, thousands of identified cSSR (combined SSR) markers will favour further genetic linkage studies. In conclusion, these data will contribute to understanding the regulation of melanin biosynthesis and help to improve the studies of pathogenicity of F. monophora.

黑化被认为是丰氏镰刀菌的重要毒力因子。然而，黑色素化的生物合成机制仍然未知。因此，我们使用了下一代测序技术来研究转录组和数字基因表达数据，这些数据是宝贵的资源，可以更好地理解调节独脚镰刀菌黑色素化的分子和生物学机制。我们从头开始使用Illumina RNA-seq系统对亲本（CBS 122845）和白化病（CBS 125194）菌株进行转录组组装和数字基因表达（DGE）分析。通过对NR，Swiss-Prot，基因本体论，直系同源簇和《京都议定书》的基因和基因组百科全书（KEGG）进行BLAST搜索，总共发现了17352个带注释的单基因（E值<1e‒5）。总共2 283个单基因被判断为两种基因型之间的差异表达。我们确定了编码黑色素生物合成途径中关键酶的大多数基因，包括聚酮合酶（pks），铜氧化酶（mco），漆酶，酪氨酸酶和尿黑酸1,2-二加氧酶（hmgA。）。DEG分析显示DHN途径中关键基因的广泛下调，而白化突变体的DOPA途径中有上调。实时RT-PCR证实了部分基因的转录水平，而关键酶的关键作用则通过体外的抑制剂或底物测试得以证实。同时，在单核镰刀菌的转录组中鉴定了涉及光感测，细胞壁合成，形态和环境胁迫的基因数目。。此外，从21 600个共有序列中鉴定出3 353个SSR（简单序列重复）标记。DNH途径的阻断是白化病菌株中黑色素缺乏的最可能原因，而在这两个途径上游，pheomelanin和pyomelanin的产生可能受到未知转录因子的调节。涉及抗氧化剂，辐射和极端温度的环境耐受性的大多数基因也被组装并注释在独脚镰刀菌的转录组中。此外，数千种已鉴定的cSSR（组合SSR）标记将有助于进一步的遗传连锁研究。总之，这些数据将有助于理解黑色素生物合成的调控，并有助于改善独脚金丝桃致病性的研究。