Publicação
Epigenetic marks in Grapevine – Plasmopara viticola interaction: The role of DNA Methyltransferases
| Resumo: | Vitis vinifera L. is known for being one of the most cultivated crops worldwide, with about 7.5 million hectares of production. Of all the possible uses, wine production is the most common and exceptionally relevant practice in several countries. However, the cultivated grapevine, Vitis vinifera, is susceptible to a considerable number of pathogens, such as downy mildew, which negatively influences the quality and yield of grapevine, thus affecting wine production. Downy mildew disease, caused by the biotrophic oomycete Plasmopara viticola (Berk. et Curt.) Berl. et de Toni, was accidentally introduced in Europe in the 19th century. After spreading throughout the European wine regions, the presence of this pathogen led to severe production losses. Currently, the preventive use of phytochemical compounds on each growing season is the strategy selected to deal with this disease, leading to high environmental, economic and health costs. Therefore, characterization of the resistance of some Vitis species and V. vinifera genotypes to Plasmopara viticola is necessary in order to define sustainable control measures for this disease. Epigenetic modifications are important in inducing phenotypic diversity, including in plant resistance responses, by controlling defense-related gene expression levels. In this work, it was possible to identify and characterize nine DNA methyltransferases genes present in Vitis vinifera. These genes are distributed in eight of the nineteen known chromosomes of Vitis, and some are located near genes that are associated with Vitis vinifera resistance against P. viticola. It was possible to classify the identified methyltransferases into four groups already known in plants, namely methyltransferase (MET), chromomethylases (CMT), domains rearranged methyltransferase (DRM), and DNA methyltransferase homolog (DNMT). Global DNA methylation patterns were determined and correlated with the expression of DNA methyltransferases genes in two distinct cultivars of Vitis vinifera, tolerant and susceptible, after inoculation with P. viticola. The levels of genomic DNA methylation observed for both cultivars were distinct. The expression of the identified methyltransferases showed some evidence of presence in the regulation of methylation during the interaction between grapevine and downy mildew. The results obtained suggested that there was a relationship between hypomethylation and the cultivar tolerant to the pathogen. Thus, two genes were shown to be involved in the epigenetic modulation associated with the establishment of the incompatible interaction. Further studies will have to be carried out in the framework of better understanding the methylation patterns of DNA methyltransferases genes in grapevine leaves. |
|---|---|
| Autores principais: | Pereira, Gonçalo Nuno Rodrigues |
| Assunto: | Vitis vinifera plasmopara viticola epigenetics methylation DNA methyltransferases epigenética metilação DNA metiltransferases |
| Ano: | 2021 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | Vitis vinifera L. is known for being one of the most cultivated crops worldwide, with about 7.5 million hectares of production. Of all the possible uses, wine production is the most common and exceptionally relevant practice in several countries. However, the cultivated grapevine, Vitis vinifera, is susceptible to a considerable number of pathogens, such as downy mildew, which negatively influences the quality and yield of grapevine, thus affecting wine production. Downy mildew disease, caused by the biotrophic oomycete Plasmopara viticola (Berk. et Curt.) Berl. et de Toni, was accidentally introduced in Europe in the 19th century. After spreading throughout the European wine regions, the presence of this pathogen led to severe production losses. Currently, the preventive use of phytochemical compounds on each growing season is the strategy selected to deal with this disease, leading to high environmental, economic and health costs. Therefore, characterization of the resistance of some Vitis species and V. vinifera genotypes to Plasmopara viticola is necessary in order to define sustainable control measures for this disease. Epigenetic modifications are important in inducing phenotypic diversity, including in plant resistance responses, by controlling defense-related gene expression levels. In this work, it was possible to identify and characterize nine DNA methyltransferases genes present in Vitis vinifera. These genes are distributed in eight of the nineteen known chromosomes of Vitis, and some are located near genes that are associated with Vitis vinifera resistance against P. viticola. It was possible to classify the identified methyltransferases into four groups already known in plants, namely methyltransferase (MET), chromomethylases (CMT), domains rearranged methyltransferase (DRM), and DNA methyltransferase homolog (DNMT). Global DNA methylation patterns were determined and correlated with the expression of DNA methyltransferases genes in two distinct cultivars of Vitis vinifera, tolerant and susceptible, after inoculation with P. viticola. The levels of genomic DNA methylation observed for both cultivars were distinct. The expression of the identified methyltransferases showed some evidence of presence in the regulation of methylation during the interaction between grapevine and downy mildew. The results obtained suggested that there was a relationship between hypomethylation and the cultivar tolerant to the pathogen. Thus, two genes were shown to be involved in the epigenetic modulation associated with the establishment of the incompatible interaction. Further studies will have to be carried out in the framework of better understanding the methylation patterns of DNA methyltransferases genes in grapevine leaves. |
|---|