Investigations carried out on secondary metabolites produced in culture by a hypovirulent strain of Cryphonectria parasitica allowed the isolation of several compounds which were characterized by NMR analysis and derivatization reactions. The most abundant metabolite was a new compound, called cryphonectric acid (1). Other metabolites were diaporthin, the only known phytotoxic compound isolated...

Unencapsidated double-stranded viral RNAs belonging to the genus Hypovirus attenuate virulence of the chestnut blight fungus, Cryphonectria parasitica. A full-length cDNA clone of hypovirus CHV1-713 double-stranded RNA was recently shown to be infectious when introduced into the C. parasitica genome by DNA-mediated transformation. In this study, we show that the viral RNA derived from the chrom...

Transmission of mycoviruses that attenuate virulence (hypovirulence) of pathogenic fungi is restricted by allorecognition systems operating in their fungal hosts. We report the use of systematic molecular gene disruption and classical genetics for engineering fungal hosts with superior virus transmission capabilities. Four of five diallelic virus-restricting allorecognition [vegetative incompat...

Genetic nonself recognition systems such as vegetative incompatibility operate in many filamentous fungi to regulate hyphal fusion between genetically dissimilar individuals and to restrict the spread of virulence-attenuating mycoviruses that have potential for biological control of pathogenic fungi. We report here the use of a comparative genomics approach to identify seven candidate polymorph...

Cryphonectria hypovirus 1 (CHV1) is a mycovirus which decreases the virulence of its fungal host Cryphonectria parasitica, the causal agent of chestnut blight recently introduced in Europe. The understanding of the evolutionary processes which have shaped CHV1 populations in Europe is required to develop a sustainable biocontrol strategy targeting chestnut blight and effective in European chest...

The mycovirus cryphonectria hypovirus 1 (CHV1) causes proliferation of vesicles in its host, Cryphonectria parasitica, the causal agent of chestnut blight. These vesicles have previously been shown to contain both CHV1 genomic double-stranded RNA (dsRNA) and RNA polymerase activity. To determine the cellular origins of these virus-induced membrane structures, we compared the fractionation of se...

Chestnut blight has spread throughout Europe since the introduction of its causal agent, Cryphonectria parasitica, >70 years ago. In our study, we analyzed diversity vegetative compatibility (vc) and microsatellite genotypes C. as well sequence hypovirus 1 (CHV1) in six populations from Switzerland, Croatia, North Macedonia. Resampling local that were already investigated more than a decade ...

Hypoviruses are a family of cytoplasmically replicating RNA viruses of the chestnut blight fungus Cryphonectria parasitica. Members of this mycovirus family persistently alter virulence (hypovirulence) and related fungal developmental processes, including asexual and sexual sporulation. In order to gain a better understanding of the molecular basis for these changes, we have developed a C. para...