Kiselev K.V., Tyunin A.P., Karetin Y.A.
В журнале Acta Physiologiae Plantarum
Год: 2013 Том: 35 Страницы: 1843-1851
DNA methylation, especially cytosine methylation, is known to play an important role in various developmental processes and defense mechanisms in plants and other organisms. The level and pattern of cytosine methylation are determined by both DNA methylation and demethylation machineries. DNA methylation is known to be established and maintained by DNA methyltransferases, whereas active DNA demethylation is performed by DNA glycosylases. In our previous study, the expression of methylatransferases in cell cultures of Vitis amurensis was studied. The purpose of the present work was to analyze demethylase (Dem) gene expression in the control (V2) and transformed with rolB gene (VB2) from Agrobacterium rhizogenes cell cultures of V. amurensis under the influence of 5-azacytidine (azaC) induced DNA demethylation and treatment with salicylic acid (SA), a plant stress phytohormone. The lowest total Dem expression was detected in the V. amurensis calli of the control V2 cell culture without treatment, while higher Dem expression was detected in the leaves of the 8-year-old V. amurensis plant. Treatment with azaC and SA significantly increased total Dem expression in the V. amurensis V2 and VB2 cell cultures 1.4–3.2 times. Using frequency analysis of reverse transcriptase PCR products obtained with degenerate primers and real-time PCR we analyzed expression of the three Dem transcripts: VaDem1, VaDem2, and VaDem3. The deduced amino acid sequence of VaDem1 is highly homologous to the V. vinifera Ros1-like gene (XM_002277365), VaDem2 to the VvDML3-like (XM_002270849); VaDem3 to the VvDemeter-like (XM_002267274). In the cDNA of the V. amurensis cell cultures the VaDem1 transcripts were more abundant than the VaDem2 and VaDem3 transcripts. Addition of azaC and SA significantly increased the VaDem1 and VaDem2 expression. The results indicate that the VaDem2 gene (a homologue of DML3 of A. thaliana) and the VaDem1 gene (a homologue of ROS1 of A. thaliana) are important in stress response and our data suggest that the VaDem2 and VaDem1 genes are important candidates for future research on the mechanisms of plant defence responses.
