Silencing of the Nicotiana benthamiana phytoendesaturase gene by root treatment of exogenous dsRNA

RNA interference (RNAi) is a powerful tool for gene silencing. It has recently been used to design promising plant protection strategies against pests such as viruses, insects, etc. This generally requires modifying the plant genome to achieve in planta synthesis of the double-stranded RNA (dsRNA), which guides the cellular RNA interference machinery to silence the genes of interest. However, given Russian legislation, the approach in which dsRNA is synthesized by the plant itself remains unavailable for crop protection. The use of exogenously produced dsRNA appears to be a promising alternative, allowing researchers to avoid genetic modification of plants, making it possible to implement potential results in agriculture. Furthermore, exogenous dsRNAs are superior to chemical pesticides (fungicides, insecticides, etc.), which are widely used to control various plant diseases. The dsRNA acts through sequence-specific nucleic acid interactions, making it extremely selective and unlikely to harm off-target organisms. Thus, it seems promising to utilize RNAi technology for agricultural plant protection. In this case, questions arise regarding how to produce the required amounts of pathogen-specific exogenous dsRNA, and which delivery method will be optimal for providing sufficient protection. This work aims to utilize exogenous dsRNA to silence the Nicotiana benthamiana phytoene desaturase gene. Phytoene desaturase is a convenient model gene in gene silencing experiments, as its knockdown results in a distinct phenotypic manifestation, namely, leaf bleaching. The dsRNA synthesis for this work was performed in vivo in Escherichia coli cells, and the chosen delivery method was root treatment through watering, both techniques being as simple and accessible as possible. It is surmised that the proposed approach could be adapted for broader use of RNAi technologies in agricultural crop protection.

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