AEDL peptide and NaCl affect on the ultrastructure and expression of DNA and lysine methyltransferase genes in Nicotiana tabacum L. regenerants

Due to its fixed nature, plants have a developed system of adaptation to environmental changes. The most studied epigenetic modifications of the genome are DNA methylation and histone proteins. Unlike animals, in which the epigenetic status is updated in each generation, in plants, epimutations can be steadily inherited, and therefore are important for evolution. Salinity is the most important abiotic stress for plants. Along with morphological changes as a result of the action of a high concentration (150 mM) of NaCl on tobacco regenerants (Nicotiana tabacum L.), changes in the ultrastructure of cell compartments in plant tissues, in particular nuclei and mitochondria, were observed. The mutual transformation of heterochromatin and euchromatin is primarily due to modifications of the histone proteins and the main modifications are the methylation of lysine residues. The presence of NaCl leads to an increase in the expression of the lysine methyltransferase gene - SUVR3, methylated H3K9, and decreased in the expression of the ASHR3 gene encoding the lysine methyltransferase, methylated H3K4. Sodium chloride causes an increase in the expression of the gene SNF2, an actin-dependent chromatin remodulator, 2 times. Proteins of the SNF2 complex untie the bonds between DNA and histones, increasing access to DNA. De novo methylation in plants is carried out by the unique enzyme DRM2, which is absent in animals. A high salt concentration causes an increase in the expression gene of DNA methyltransferase - DRM2 by 30%. Moreover, the expressions of DNA-supporting methyltransferases genes remains almost unchanged. The short tetrapeptide AlaGluAspLeu (AEDL) at a concentration of 10-8M significantly stimulates the growth and development of tobacco calluses Nicotiana tabacum. Significant differences in the packing of chromatin in the presence of AEDL were detected both in normal conditions and under the action of NaCl. Significant differences in the packing of chromatin in the presence of AEDL were detected both in normal conditions and under the action of NaCl. In the presence of tetrapeptide, a significant decrease in the expression of genes of the SNF2 family is observed, the level of gene expression genes of methyltransferase DNA remains practically unchanged, the expression of histone methyltransferase genes also remains unchanged or decreases even. In the presence of the tetrapeptide AlaGluAspLeu and sodium chloride together, the expression of the lysine methyltra