The genus Colletotrichum comprises a large number of filamentous fungi responsible for anthracnose diseases in many tropical and subtropical fruits and vegetables. In particular, Colletotrichum higginsianum infects Brassicaceae species, including Arabidopsis . The C. higginsianum strain IMI349063A is naturally infected with a dsRNA virus, named Colletorichum higginsianum non-segmented virus (ChNRV1). Here, we investigated the biological effect of ChNRV1 in C. higginsianum by comparing strains with and without the virus. ChNRV1 does not have an effect on C. higginsianum growth under salt and cell-wall stress conditions. However, thermal stress reduced C. higginsianum growth rate, this effect being more evident in the wild-type C. higginsianum strain containing the virus. Although ChNRV1 had no effect in conidiation, conidia were narrower when the virus is present. More importantly, ChNRV1 causes a mild increase in C. higginsianum virulence (hypervirulence) when infecting Arabidopsis plants. These findings indicated that, whereas the ChNRV1 mycovirus does not impair growth and conidiation of C. higginsianum , it confers hypervirulence to the fungal host. These findings will help in future research on the effect of mycoviral infection on pathogenic fungi in plant species of agronomical relevance.

中文翻译：

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dsRNA 真菌病毒 ChNRV1 在真菌植物病原体 Colletotrichum higginsianum 中引起轻度超毒

炭疽菌属包含大量丝状真菌，在许多热带和亚热带水果和蔬菜中会导致炭疽病。特别地，Colletotrichum higginsianum 感染十字花科物种，包括拟南芥。C. higginsianum 菌株 IMI349063A 自然感染了 dsRNA 病毒，名为 Colletorichum higginsianum 非节段病毒 (ChNRV1)。在这里，我们通过比较有和没有病毒的菌株来研究 ChNRV1 在 C. higginsianum 中的生物学效应。ChNRV1 在盐和细胞壁胁迫条件下对 C. higginsianum 生长没有影响。然而，热应激降低了 C. higginsianum 的生长速度，这种影响在含有病毒的野生型 C. higginsianum 菌株中更为明显。尽管 ChNRV1 对分生孢子没有影响，当病毒存在时，分生孢子会变窄。更重要的是，ChNRV1 在感染拟南芥植物时会导致 C. higginsianum 毒力（超毒力）轻度增加。这些发现表明，虽然 ChNRV1 真菌病毒不损害 C. higginsianum 的生长和分生孢子，但它赋予真菌宿主超毒力。这些发现将有助于未来研究真菌病毒感染对具有农艺相关性的植物物种中病原真菌的影响。