Affiliation:
1. Natural Resources Institute Finland, Helsinki, Finland
Abstract
ABSTRACT
The fungal genus
Heterobasidion
includes some of the most devastating conifer pathogens in the boreal forest region. In this study, we showed that the alphapartitivirus Heterobasidion partitivirus 13 from
Heterobasidion annosum
(HetPV13-an1) is the main causal agent of severe phenotypic debilitation in the host fungus. Based on RNA sequencing using isogenic virus-infected and cured fungal strains, HetPV13-an1 affected the transcription of 683 genes, of which 60% were downregulated and 40% upregulated. Alterations observed in carbohydrate and amino acid metabolism suggest that the virus causes a state of starvation, which is compensated for by alternative synthesis routes. We used dual cultures to transmit HetPV13-an1 into new strains of
H. annosum
and
Heterobasidion parviporum
. The three strains of
H. parviporum
that acquired the virus showed noticeable growth reduction on rich culturing medium, while only two of six
H. annosum
isolates tested showed significant debilitation. Based on reverse transcription-quantitative PCR (RT-qPCR) analysis, the response toward HetPV13-an1 infection was somewhat different in
H. annosum
and
H. parviporum
. We assessed the effects of HetPV13-an1 on the wood colonization efficacy of
H. parviporum
in a field experiment where 46 Norway spruce trees were inoculated with isogenic strains with or without the virus. The virus-infected
H. parviporum
strain showed considerably less growth within living trees than the isolate without HetPV13-an1, indicating that the virus also causes growth debilitation in natural substrates.
IMPORTANCE
A biocontrol method restricting the spread of
Heterobasidion
species would be highly beneficial to forestry, as these fungi are difficult to eradicate from diseased forest stands and cause approximate annual losses of €800 million in Europe. We used virus curing and reintroduction experiments and RNA sequencing to show that the alphapartitivirus HetPV13-an1 affects many basic cellular functions of the white rot wood decay fungus
Heterobasidion annosum
, which results in aberrant hyphal morphology and a low growth rate. Dual fungal cultures were used to introduce HetPV13-an1 into a new host species,
Heterobasidion parviporum
, and field experiments confirmed the capability of the virus to reduce the growth of
H. parviporum
in living spruce wood. Taken together, our results suggest that HetPV13-an1 shows potential for the development of a future biocontrol agent against
Heterobasidion
fungi.
Publisher
American Society for Microbiology
Subject
Virology,Insect Science,Immunology,Microbiology
Cited by
43 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献