Publicação
CHV1 hypovirus infection on Cryphonectria parasitica - effects on pathogenesis and laccase activity
| Resumo: | Biological control by hypovirulence is an efficient method to control chestnut blight. The presence of Cryphonectria hypovirus 1 (CHV1) in Cryphonectria parasitica reduces its parasitic growth and sporulation capacity, female fertility, pigmentation, oxalate accumulation and laccase production. Indeed, laccases are involved in lignin degradation, and are also considered as a virulence determinant in C. parasitica. The aim of this work was to evaluate the laccase production in both virulent and converted strains and to access the virulence of these strains in vitro and on dormant chestnut stems. Five isolates were converted with two characterized hypovirulent C. parasitica isolates (RBB111, SR44.2). To evaluate the virulence of the isolates, dormant chestnut stems were inoculated with the virulent isolates, their converted ones and the hypovirulent isolates. The qualitative evaluation of laccase production was performed using Bavendamm test and RBBR test. For quantitative evaluation of laccase production strains were grown on PDB (Potato Dextrose Broth, 24g/L) and the sample readings taken by spectrophotometry using ABTS. The hypovirulent isolates used in this work has complete ability to convert virulent isolates. The infection area on chestnut stems caused by virulent strains was significantly higher (P<0.05) than the infection area caused by converted strains. In the Bavendamm test, the virulent isolates Cast13, Cast26 and VDP11 showed the highest dark area indicator of a higher enzymatic activity while the converted isolates by SR44.2 or RBB111, showed a great reduction of the coloration and this is more observed in the converted isolates by RBB111. For the quantitative assay the specific activity was determined and showed that among all the virulent isolates VDP11 had the highest laccase activity followed by Cast13 and this activity was reduced also in the converted ones especially with RBB111. |
|---|---|
| Autores principais: | Boumnigel, Houssem |
| Assunto: | Cryphonectria parasitica Virulence Laccase |
| Ano: | 2022 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Instituto Politécnico de Bragança |
| Idioma: | inglês |
| Origem: | Biblioteca Digital do IPB |
| Resumo: | Biological control by hypovirulence is an efficient method to control chestnut blight. The presence of Cryphonectria hypovirus 1 (CHV1) in Cryphonectria parasitica reduces its parasitic growth and sporulation capacity, female fertility, pigmentation, oxalate accumulation and laccase production. Indeed, laccases are involved in lignin degradation, and are also considered as a virulence determinant in C. parasitica. The aim of this work was to evaluate the laccase production in both virulent and converted strains and to access the virulence of these strains in vitro and on dormant chestnut stems. Five isolates were converted with two characterized hypovirulent C. parasitica isolates (RBB111, SR44.2). To evaluate the virulence of the isolates, dormant chestnut stems were inoculated with the virulent isolates, their converted ones and the hypovirulent isolates. The qualitative evaluation of laccase production was performed using Bavendamm test and RBBR test. For quantitative evaluation of laccase production strains were grown on PDB (Potato Dextrose Broth, 24g/L) and the sample readings taken by spectrophotometry using ABTS. The hypovirulent isolates used in this work has complete ability to convert virulent isolates. The infection area on chestnut stems caused by virulent strains was significantly higher (P<0.05) than the infection area caused by converted strains. In the Bavendamm test, the virulent isolates Cast13, Cast26 and VDP11 showed the highest dark area indicator of a higher enzymatic activity while the converted isolates by SR44.2 or RBB111, showed a great reduction of the coloration and this is more observed in the converted isolates by RBB111. For the quantitative assay the specific activity was determined and showed that among all the virulent isolates VDP11 had the highest laccase activity followed by Cast13 and this activity was reduced also in the converted ones especially with RBB111. |
|---|