Role of tri18 gene in Epiroridin E production and toxin resistance mechanisms in Paramyrothecium roridum

Type D trichothecene toxins represent a class of macrocyclic trichothecene toxins with significant cytotoxicities towards human and crops. These toxins can also be used as anti-tumor compounds by the combination of antibody-drug conjugate. Therefore, it is urgent to investigate the biosynthetic routine of type D trichothecene toxins and explore type D trichothecene toxin-resistant genes, in order to ameliorate the hazard of trichothecene toxins and to facilitate the heterologous expression of toxin-biosynthetic cluster. In this study, tri18 gene was firstly knocked out in Paramyrothecium roridum, leading to the complete absence of type D trichothecene toxin epiroridin E, which can be restored by the complement of tri18 gene. Additionally, the knockout of tri18 gene led to a significant reduction in the pathogenicity of P. roridum towards pumpkin. Meanwhile, the enzymatic properties of Tri18 protein towards trichothecene deoxynivalenol (DON) toxin were also characterized. Moreover, tri3 and tri17KR with broad spectrum toxin-resistance function within the tri cluster were initially discovered through heterologous expression in toxin-sensitive Saccharomyces cerevisiae. And this study provides innovative type D trichothecene toxin resistant enzymes, which can provides green platform for the production of type D trichothecene toxins, thus promoting the application of these toxins in biomedical field. [Display omitted] •The key role of tri18 gene for the biosynthesis of type D trichothecenes was initially illustrated.•Two novel type D trichothecene toxin resistant genes in tri cluster were excavated.•The key role of tri18 for the pathogenicity of P. roridum towards pumpkin was initially verified.•The toxin-resistance mechanism of tri3 and tri17KR were proposed.•The in vitro biochemical function of Tri18 protein was also investigated.