Comparison Of Methods To Eliminate Virus From Cryphonectria Parasitica And Cloning Of The Target Gene Involved In The Symptom Expression During Infection By A Hypovirus

The interaction between virus and host is one of the most important front of virology. A novel hypovirus/Cryphonectria parasitica system was adopted to study the interaction between a virus and its host. It was found that the hypovirus could be eliminated after protoplast regeneration in C. parasitica, a method that can be used to eliminate virus for other fungi. By insertional mutagenesis of the transgenic strain LCI with a single-cross random integration plasmid library that contain random DNA of the virus-free wild type C. parasitica, many mutants with varied phenotype were obtained. One of such mutants, B910, sporulated well while was still infected by the viruses. Southern blot analysis showed it was a single insertional mutant. A fragment of 888bp that flanks the insertion site was recovered by plasmid rescue. Sequence analysis indicated that the insertion interrupted an ORF (termed CPTAl) that encodes a protein similar to a GAL4-like transcription activator of Colletotrichum lindmuthianum with 64% identity and 75% positives. This result implies that CPTAl maybe the target of the hypovirus and whose funtion was modulated by the virus to interfere with the sporulation process of the fungus.