Infl uence of interference silencing of the gene of translation initiation factors eIF(iso)G and eIF(iso)E on the resistance of the clone stone fruits rootstock 146-2 and commercial plum variety Startovaya to the Plum pox virus

The method of RNA interference gene expression silencing was used to obtain Plum pox virus (PPV) resistant rootstock and commercial variety Startovaya.For this purpose, a vector with self-complementary sequences of the 578 bp eIF(iso)4G and eIF(iso)E genes fragment was created. The eIF(iso)4G and eIF(iso)E genes encodes factors of initiation of translation involved in the life cycle of a Plum pox virus. A strong promoter of the ribulose-1.5-bisphosphate carboxylase/oxygenase (RuBisCo) gene was chosen to drive the expression of RNA interference hairpin in full and truncated variants. Successful genetic transformation of the 146-2 rootstock and variety Startovaya were carried out by A. tumefaciens CBE21 strain. Whole leaves from in vitro cultured shoots were used as an explant source. The nptII and hpt genes coding for neomycin II and hygromycin phosphotransferase were used as a plant-selectable markers. In our experiments, 5 independent transgenic lines of clonal rootstock and variety were obtained and acclimatized to greenhouse conditions. Th eir status was confirmed by PCR and Southern blot analyses. The transformation efficiency was 0.3-0.4 %. One of these lines was grafted with PPV-infected plum buds and its resistance was verified by ELISA. The use of a full-length gene promoter of the small subunit of ribulosobiephosphate carboxylase (RBCS) in the transformation of plants of the Starter variety led to a decrease in plant viability in the case of suppression of the eIF(iso)4E gene and ensured stability at least in the first year after inoculation in the case of suppression of the eIF(iso)4G gene.

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