Forest Health and Biodiversity, Natural Resources Institute Finland, Helsinki, Finland.
Department of Biology, University of Oulu, Oulu, Finland.
Front Cell Infect Microbiol. 2019 Mar 26;9:64. doi: 10.3389/fcimb.2019.00064. eCollection 2019.
spp. root rot fungi are highly destructive forest pathogens of the northern boreal forests, and are known to host a diverse community of partitiviruses. The transmission of these mycoviruses occurs horizontally among host strains via mycelial anastomoses. We revealed using dual cultures that virus transmission rates are affected by pre-existing virus infections among two strains of . The transmission efficacy of mycovirus HetPV15-pa1 to a pre-infected host was elevated from zero to 50% by the presence of HetPV13-an1, and a double infection of these viruses in the donor resulted in an overall transmission rate of 90% to a partitivirus-free recipient. On contrary, pre-existing virus infections of two closely related strains of HetPV11 hindered each other's transmission, but had unexpectedly dissimilar effects on the transmission of more distantly related viruses. The co-infection of HetPV13-an1 and HetPV15-pa1 significantly reduced host growth, whereas double infections including HetPV11 strains had variable effects. Moreover, the results showed that RdRp transcripts are generally more abundant than capsid protein (CP) transcripts and the four different virus strains express unique transcripts ratios of RdRp and CP. Taken together, the results show that the interplay between co-infecting viruses and their host is extremely complex and highly unpredictable.
种根腐真菌是北方北方森林中具有高度破坏性的森林病原体，已知其宿主有多种细小病毒。这些真菌病毒通过菌丝吻合在宿主菌株之间水平传播。我们通过双培养揭示，病毒传播率受到两种菌株之间预先存在的病毒感染的影响。HetPV13-an1 的存在将 HetPV15-pa1 对预先感染宿主的传播效率从 0 提高到 50%，而这两种病毒在供体中的双重感染导致对无部分病毒的受体的总体传播率达到 90%。相反，两种密切相关的 HetPV11 菌株的预先存在的病毒感染相互阻碍彼此的传播，但对传播更远相关的病毒有不同的影响。HetPV13-an1 和 HetPV15-pa1 的共同感染显著降低了宿主的生长，而包括 HetPV11 株在内的双重感染则具有不同的影响。此外，结果表明 RdRp 转录物通常比衣壳蛋白 (CP) 转录物更丰富，并且四种不同的病毒株表达独特的 RdRp 和 CP 转录物比例。总之，结果表明，共感染病毒及其宿主之间的相互作用极其复杂且高度不可预测。
