Research Area : Molecular Virology

Using two combinations, Chestnut/chestnut blight fungus/mycoviruses and fruit trees/root rot fungi/mycoviruses, viral replication and symptom expression were investigated at the molecular and cellular levels. Obtained knowledge and achieved technical advance will be integrated into into virocontrol (a form of biological control using viruses) of the plant pathogenic fungi.

Several viruses, challenging the concept or rules of viruses, have been discovered from lower eukaryotes. The objective of this project is to reveal the unique neo-lifestyle of Yado-nushi virus 1 (YnV1) and Yado-nushi virus 1 (YnV1) newly discovered from an important pathogen of perennial fruit trees, Rosellinia necatrix. We show that YkV1 highjacks the capsid of YnV1 to heteroencapsidate YkV1 genomic RNA and replicase and use it as the replication site. Furthermore, viruses with similar mutualistic virus/virus interactions will be found in other eukaryotic organisms to show the generality of the neo-lifestyle.

Phytobiomes refer to the complex networks between plants and their associated communities of organisms including bacteria, fungi, viruses and invertebrates. Phytobiomes are becoming increasingly recognized as important factors in plant health and productivity, but in particular, little is known about the diversities of virus communities in agricultural cropping system. Taking advances of the next generation sequencing and metagenomics, our group studies on viromes in fungi and insects that are associated with crop plants. We aim to find out whether these viral communities influence their hosts and promote the health and growth of crop plants.

The availability of genome sequences of a large number of eukaryotes has led to the discovery of endogenous non-retroviral RNA virus-like elements, also known as endogenous viral elements (EVEs). These elements are considered as fossil of RNA virus integrated into host genomes by as-yet-unknown mechanisms. To gain deeper insight into the long-term viral evolution and host-virus coevolution, our research is focused on identification and analysis of the EVEs in the genome of the plants, insects and fungi.