A new area of research has become the study of the effect of genes encoding receptors for Nod factors and controlling the initiation of the development of nitrogen-fixing symbioses on non-leguminous plants. For this purpose, the genetic transformation of tomato and barley plants is carried out, the expression of receptor genes for rhizobia signaling molecules and transcription regulators is studied when they are transferred to plants under the control of constitutive and specific promoters. As a result of the conducted research, it was possible to show the possibility of activation of transferred genes in the tissues of non-leguminous plants (analysis of the content of mRNA and encoded protein), as well as to assess the changes that such transfer leads to. These studies are of a priority nature, since they are pioneering in this field and will in the future expand the range of plants entering into symbiosis with rhizobia.