Dipeptides and Glycine Modulate Development of Seedlings and Regenerants of Tobacco Nicotiana tabacum L.

It is revealed that dipeptides glycylglycine (GlyGly) and glycylaspartic acid (GlyAsp), as well as the amino acid glycine (Gly), appreciably stimulated the growth and development of tobacco (Nicotiana tabacum L.) regenerants and seedlings if they were present in a medium at 10–7 М. All three compounds GlyGly, GlyAsp, and Gly influenced the cell differentiation and morphogenic processes in the calli. The compounds modulated expression of the KNOX and GRF family genes. The profiles of induction or repression of gene expression by one and the same peptide were found to differ in tobacco regenerants and seedlings. It is concluded that GlyGly, GlyAsp, and Gly may be considered as regulators of plant growth and development, the mode of action of which is signaling and mainly epigenetic.