Abstract As a well-known edible fungus that generally grows at low temperature, Flammulina velutipes is believed to be able to withstand most undesirable microbes. However, in this study, we discovered and isolated cold-adapted bacteria that developed rapidly and caused soft rot in the stipe of F. velutipes. The pathogen was identified as Mycetocola saprophilus based on morphology, 16S rRNA sequences, and multilocus sequence typing analysis. To further understand the pathogenic mechanisms of soft rot disease in F. velutipes, we sequenced and analyzed the genome of strain JXN-3 using PacBio sequencing. The de-novo assembly of the genome of strain JXN-3 was ∼3.47 Mb, with a GC content of 66.32%. The genome was composed of 3276 genes, of which 3094 were protein coding. Many of the identified protein-coding genes were associated with the synthesis of cell wall-degrading enzymes and antifungal compounds, including chitin deacetylase, chitinase, 1,4-beta-D-glucan glucohydrolase, beta-glucanase, endoglucanase Acf2, exo-beta-1,3-glucanase and bacteriocin. Compared with other members of Mycetocola, we also found a JXN-3-unique gene cluster for synthesizing bacteriocin. These genes may contribute to the pathogenesis of soft rot in F. velutipes stipes. Future studies should further investigate the involvement of these proteins in the incidence and progression of soft rot disease in F. velutipes.

中文翻译：

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嗜冷菌Mycetocola saprophilus 的基因组和形态特征为金针菇软腐病的发病机制提供了见解

摘要 金针菇作为一种众所周知的低温生长的食用菌，被认为能够抵御大多数不良微生物。然而，在这项研究中，我们发现并分离了在 F. velutipes 的菌柄中快速发育并引起软腐病的冷适应细菌。基于形态学、16S rRNA序列和多位点序列分型分析，病原体被鉴定为Mycetocola saprophilus。为了进一步了解 F. velutipes 软腐病的致病机制，我们使用 PacBio 测序对 JXN-3 菌株的基因组进行了测序和分析。JXN-3 菌株基因组的从头组装约为 3.47 Mb，GC 含量为 66.32%。基因组由3276个基因组成，其中3094个为蛋白质编码。许多已鉴定的蛋白质编码基因与细胞壁降解酶和抗真菌化合物的合成有关，包括几丁质脱乙酰酶、几丁质酶、1,4-β-D-葡聚糖葡萄糖水解酶、β-葡聚糖酶、内切葡聚糖酶 Acf2、外切β -1,3-葡聚糖酶和细菌素。与Mycetocola 的其他成员相比，我们还发现了一个JXN-3 独特的合成细菌素基因簇。这些基因可能有助于 F. velutipes 叶柄软腐病的发病机制。未来的研究应该进一步调查这些蛋白质在 F. velutipes 软腐病的发生和进展中的作用。与Mycetocola 的其他成员相比，我们还发现了一个JXN-3 独特的合成细菌素基因簇。这些基因可能有助于 F. velutipes 叶柄软腐病的发病机制。未来的研究应该进一步调查这些蛋白质在 F. velutipes 软腐病的发生和进展中的作用。与Mycetocola 的其他成员相比，我们还发现了一个JXN-3 独特的合成细菌素基因簇。这些基因可能有助于 F. velutipes 叶柄软腐病的发病机制。未来的研究应该进一步调查这些蛋白质在 F. velutipes 软腐病的发生和进展中的作用。