Biochemical and epigenetic changes in Cryphonectria hypovirus 1- infected fungus Cryphonectria parasitica (Murr.) Barr

S ciljem određivanja učinka infekcije virusom Cryphonectria hypovirus 1 (CHV1) na intenzitet promjena u metabolizmu gljive Cryphonectria parasitica, u tri virulentna izolata gljive uneseno je šest različitih sojeva virusa talijanskog (I), francuskog (F1) i rekombiniranog talijansko-francuskog (F1/I) podtipa. Infekcija virusom CHV1 dovela je do i) indukcije antioksidacijske obrane u zaraženoj gljivi, odnosno do povećanja aktivnosti antioksidacijskih enzima glutation S-transferaze, katalaze i superoksid dismutaze, ii) do porasta aktivnosti lakaza zaražene gljive, iii) do epigenetičkih promjena, odnosno do porasta metiliranosti CpG sekvenci genoma gljive. Postavljena je hipoteza da je povećana metilacija genoma gljive C. parasitica nakon infekcije virusom čimbenik virulentnosti virusa, a ne dio obrambenog mehanizma gljive. Svi istraživani parametri pokazali su da intenzitet promjena u metabolizmu gljive ovisi o virusnom soju, a ne podtipu virusa, te o genotipu gljive domaćina i kombinaciji genoma gljive i virusa, te je naglašena važnost korištenja više virusnih sojeva i izolata gljive u pokušajima biološke kontrole.Six different strains of Cryphonectria hypovirus 1 (CHV1), of Italian (I), French (F1) and recombinant Italian-French (F1/I) subtype, were transferred into three virulent isolates of fungus Cryphonectria parasitica to determine the effect of virus infection on the fungal metabolism. CHV1 infection: i) induced antioxidative defence in infected fungus – increased activities of antioxidative enzymes glutathione S-transferase, catalase and superoxide dismutase, ii) increased activity of fungal laccases, iii) induced epigenetic changes in the genome of infected fungus – increased methylation levels at CpG sites. Methylation of C. parasitica genome upon CHV1 infection seems to be a virulence determinant of the virus rather than a part of defensive mechanism of the fungus. The severity of observed effects did not depend on virus subtype, but rather on a particular virus strain, fungal genotype, and the combination of the two, stressing the importance of using more virus strains and fungal isolates in the biocontrol efforts