In the 21st century agriculture faces the serious challenge of providing food supply in sufficient quantity and quality to the exploding human population despite  shrinking crop lands and  increasingly extreme weather conditions. In the future, agriculture can only meet this task if productivity is increased substantially. Of the biotic factors that threaten food security the most serious ones are viral diseases. Plants have evolved several defensive mechanisms to fight off viral infections. Dr. Fátyol’s laboratory uses the tools of modern plant molecular biology, including the CRISPR/Cas9 genome editing system, to study the above processes. Disentangling the details of these defence measures is important not only for the better appreciation of the molecular events taking place in plant cells, but from the standpoint of finding novel ways to improve stress tolerance in plants, thereby increasing crop yield and quality.