SteIF4E Silencing Increases Resistance of Potato cv. La Strada to Potato Virus Y, with Pleiotropic Effects on Plant Growth and Productivity

The creation of potato cultivars with resistance to virus Y (PVY) will allow one to solve successfully the problems of yield losses of this important vegetable and industrial agricultural crop. For replication and systemic spread, PVY recruits the translational apparatus of potato cells by interacting with host eIF4E translation initiation factors. By reducing the expression of genes encoding plant eIF4E, it is possible to limit both potyvirus replication in the host cell and further spread. Here, the production of potato cv. La Strada plants with inhibition of SteIF4E1 and SteIF4E2 gene expression through the use of RNA-interference technology is described. As a result of transformation with the marker-free expression cassette consisting of potato gene fragments (promoter and terminator of the StLhca3 gene and two inverted repeats of the SteIF4E1 gene separated by the Strbcs1 intron), transgenic lines with a high degree of suppression of target genes were obtained. Downregulation of SteIF4E1 and SteIF4E2 expression resulted in stunted growth and reduced overall productivity of potato plants and, at the same time, stable resistance to PVY infection. The use of a marker-free strategy in genetic transformation ensured the production of virus-resistant potato lines without inserting foreign reporter genes into their genome, which is extremely important from the point of view of environmental safety and public acceptance of genetically modified agricultural crops.