Abstract
Global food security is under threat due to overpopulation, climate change, and emerging agricultural diseases. Among these, the Virus Yellows disease severely affects sugar beet crops, reducing yields by up to 40%, with localized losses reaching 90%. Sugar beets contribute significantly to global sugar production, and France, as a leading producer, is particularly impacted. The most severe form of the disease is caused by the Beet Yellows Virus (BYV) which is transmitted by aphids. To tackle this issue, farmers are left without any efficient solution.
To address this issue, the Ionis-Paris team developed CAP'siRNA, a novel RNA interference (RNAi) platform aimed at combating BYV infections in sugar beets. CAP'siRNA was inspired by natural defense mechanisms present in plant and utilizes engineered Escherichia coli to produce long hairpin RNA (lhRNA) precursors. Our lhRNA are designed to target the RNA dependent RNA polymerase (RdRp), which regulates the replication of the BYV, and the p21, an RNA interfering suppressor gene. Once inside the plant, lhRNAs are processed into short interfering RNAs (siRNAs), which guide the RNA-induced silencing complex (RISC) to specifically degrade the viral RNA genome of the BYV, halting the virus's replication and spread.
To protect our RNAi precursors from the environment and assure its successful delivery into sugar beets, we implemented a specific sequence in them called Origin of Assembly Sequence (OAS), from the Tobacco Mosaic Virus (TMV). It enables the proper encapsidation of our RNAi precursors by TMV coat proteins. Then, we engineered another strain of Escherichia coli to produce these TMV coat proteins.
The solution is non-GMO, biodegradable, and targets only the virus, avoiding the ecological damage caused by traditional insecticides. Moreover, the platform is scalable and can be adapted to address other viral diseases in various crops, presenting a new avenue for sustainable agriculture.
