Location: Application Technology ResearchTitle: Characterization of transcriptional responses to genomovirus infection of the white mold fungus, Sclerotinia sclerotiorum
Submitted to: Viruses
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/25/2022
Publication Date: 8/27/2022
Citation: Pedersen, C.J., Marzano, S.L. 2022. Characterization of transcriptional responses to genomovirus infection of the white mold fungus, Sclerotinia sclerotiorum. Viruses. 14(9). Article #1892. https://doi.org/10.3390/v14091892.
Interpretive Summary: Sclerotinia sclerotiorum is a devastating plant pathogen. Soybean leaf associated gemygorvirus-1 (SlaGemV-1) causes visible changes in the fungal morphology, infection potential, and growth rate of S. sclerotiorum. Here, we have determined that alongside these phenotypes, differences in genetic expression are also readily visible by RNA-Seq and differential expression analysis.
Technical Abstract: Soybean leaf associated gemygorvirus-1 (SlaGemV-1) is a CRESS-DNA virus classified in the family Genomoviridae, which causes hypovirulence and abolishes sclerotia formation in infected fungal species. To investigate the mechanisms involved in the induction of hypovirulence, genome-wide of gene expression was compared between the virus free and SlaGemV-1-infected Sclerotinia sclerotiorum strain DK3. Overall, 5,026 genes were differentially expressed with ~50.6% upregulated and 49.4% downregulated (p = 0.05). Differential expression shows changes in genes related to pathogenicity, including plant cell wall degradation, signal cascades, transcription factors, environmental interaction, ROS suppression, sclerotia formation, and secreted proteins. Most of the cell-cycle genes, DNA repair and replication pathways showed up-regulation, and a part of the ubiquitylation pathways was also upregulated under SlaGemV-1 infection. Additionally, silencing pathways genes are downregulated in the three RdRp genes while upregulated in argonaute-4 only. Interestingly, genes relating to oxalic acid biosynthesis do not show differential expression, but the oxalate decarboxylase 1 & 2 genes necessary for oxalate catabolism do show down-regulation. Furthermore, TEM imaging reveals virus particles collected in large numbers along the inner membrane maintained within vesicles, suggesting endocytosis as the route of horizonal transmission.