Novel RNA- or DNA-based substances can protect plants from viruses, scientists show

Individually tailored RNA or DNA-based molecules are able to reliably fight off viral infections in plants, according to a new study by the Martin Luther University Halle-Wittenberg (MLU).

The researchers were able to fend off a common virus using the new active substances in up to 90% of cases. They also developed a method for finding substances tailored specifically to the virus. The team has now patented the method.

During a viral infection, the plant's cells are hijacked by the virus to multiply itself. Key products of this process are viral RNA molecules that serve as blueprints for the production of proteins. "A virus cannot reproduce without producing its proteins," explains Professor Sven-Erik Behrens from the Institute of Biochemistry and Biotechnology at MLU. For years, his team has been working on ways to disrupt this process and degrade the viral RNA molecules inside the cells.

In the new study, the researchers describe how this can be achieved using the so-called "antisense" method. It relies on short, synthetically produced DNA molecules known as antisense oligonucleotides (ASOs). In the plant cells, the ASOs direct cellular enzymes acting as scissors towards the foreign RNA so they can degrade it.

The results were impressive: Experiments using the optimized ASO active substances showed that plants were protected against infection with a model virus in up to 90% of the cases.

Image source: Uni Halle / Markus Scholz.