Virome analysis of an ectomycorrhizal fungus Suillus luteus revealing potential evolutionary implications

Abstract

Suillus luteus is a widespread edible ectomycorrhizal fungus that holds significant importance in both ecological and economic value. Mycoviruses are ubiquitous infectious agents hosted in different fungi, with some known to exert beneficial or detrimental effects on their hosts. However, mycoviruses hosted in ectomycorrhizal fungi remain poorly studied. To address this gap in knowledge, we employed next-generation sequencing (NGS) to investigate the virome of S. luteus. Using BLASTp analysis and phylogenetic tree construction, we identified 33 mycovirus species, with over half of them belonging to the phylum Lenarviricota, and 29 of these viruses were novel. These mycoviruses were further grouped into 11 lineages, with the discovery of a new negative-sense single-stranded RNA viral family in the order Bunyavirales. In addition, our findings suggest the occurrence of cross-species transmission (CST) between the fungus and ticks, shedding light on potential evolutionary events that have shaped the viral community in different hosts. This study is not only the first study to characterize mycoviruses in S. luteus but highlights the enormous diversity of mycoviruses and their implications for virus evolution.

A Novel Strain of Fusarium oxysporum Alternavirus 1 Isolated from Fusarium oxysporum f. sp. melonis Strain T-BJ17 Confers Hypovirulence and Increases the Sensitivity of Its Host Fungus to Difenoconazole and Pydiflumetofen

“…It was stated that the criteria for demarcating species should consider the number of dsRNA segments and the presence and homology of dsRNA 4 (https://ictv.global/files/ proposals/approved?fid=11959#block-teamplus-page-title, accessed on 5 March 2024). Thus far, eighteen mycoviruses have been assigned as members of the family Alternaviridae [11,[13][14][15][16][17][18][19][47][48][49][50][51][52][53][54][55]. Except for FaAV1, which is composed of two dsRNA segments [13], the remaining seventeen alternaviruses contain three or four dsRNA segments [11,[14][15][16][17][18][19][47][48][49][50][51][52][53][54][55].…”

“…It was stated that the criteria for demarcating species should consider the number of dsRNA segments and the presence and homology of dsRNA 4 ( , accessed on 5 March 2024). Thus far, eighteen mycoviruses have been assigned as members of the family Alternaviridae [ 11 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ]. Except for FaAV1, which is composed of two dsRNA segments [ 13 ], the remaining seventeen alternaviruses contain three or four dsRNA segments [ 11 , 14 , 15 , 16 , 17 , 18 , 19 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ].…”

“…Thus far, eighteen mycoviruses have been assigned as members of the family Alternaviridae [ 11 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ]. Except for FaAV1, which is composed of two dsRNA segments [ 13 ], the remaining seventeen alternaviruses contain three or four dsRNA segments [ 11 , 14 , 15 , 16 , 17 , 18 , 19 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ]. Among them, eleven alternaviruses, namely Aspergillus heteromorphus alternavirus 1 (AheAV1) [ 49 ], Cordyceps chanhua alternavirus 1 (CcAV1) [ 52 ], Dactylonectria torresensis alternavirus 1 (DtAV1) [ 53 ], FgAV1 [ 14 ], FiAV1 [ 15 ], FnAV1 [ 16 ], FpgAV1 [ 18 ], FpAV1 [ 17 ], Ilyonectria crassa alternavirus 1 (IcAV1) [ 51 ], Ilyonectria robusta alternavirus 1 (IrAV1) [ 53 ], and Suillus luteus alternavirus 1 (SluAV1) [ 55 ], contain three dsRNA segments, while six alternaviruses, including AaV1 [ 47 ], Aspergillus foetidus virus (AfV) [ 54 ], Aspergillus virus 341 (AsV341) [ …”

“…Except for FaAV1, which is composed of two dsRNA segments [ 13 ], the remaining seventeen alternaviruses contain three or four dsRNA segments [ 11 , 14 , 15 , 16 , 17 , 18 , 19 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ]. Among them, eleven alternaviruses, namely Aspergillus heteromorphus alternavirus 1 (AheAV1) [ 49 ], Cordyceps chanhua alternavirus 1 (CcAV1) [ 52 ], Dactylonectria torresensis alternavirus 1 (DtAV1) [ 53 ], FgAV1 [ 14 ], FiAV1 [ 15 ], FnAV1 [ 16 ], FpgAV1 [ 18 ], FpAV1 [ 17 ], Ilyonectria crassa alternavirus 1 (IcAV1) [ 51 ], Ilyonectria robusta alternavirus 1 (IrAV1) [ 53 ], and Suillus luteus alternavirus 1 (SluAV1) [ 55 ], contain three dsRNA segments, while six alternaviruses, including AaV1 [ 47 ], Aspergillus foetidus virus (AfV) [ 54 ], Aspergillus virus 341 (AsV341) [ 50 ], FoAV1 [ 11 ], FsAV1 [ 19 ], and Stemphylium lycopersici alternavirus 1 (SlAV1) [ 48 ], contain four dsRNA segments. Usually, dsRNA 1 encodes RdRp, dsRNA 2 encodes a conserved protein with an unknown function, dsRNA 3 encodes capsid protein (CP), and dsRNA 4, when present, encodes a non-conserved protein with an unknown function that is often non-homologous among alternaviruses.…”