Potyviruses constitute one of the largest groups of phytopathogenic viruses. They group together such viruses as plum pox virus and potato virus Y and cause major crop losses. The genetic analysis of the resistance to these viruses in cultivated or model plants has highlighted the central role of the plant protein eIF4E1, not only for protein synthesis in the plant but also for the development of the virus in the plant. Indeed, when plants become infected, Potyviruses recruit these proteins in order to multiply.

Mutations of this protein have been selected in many cultivated and wild species, preventing good virus multiplication and thus leading to resistance. Such is the case for chili, tomato and pea plants.

Researchers at the Inra and the CEA have shown that these targeted modifications of the eIF4E1 protein can be reproduced and transferred to a plant lacking natural resistance, in order to provide resistance without affecting the plant's development. To do this, they produced a synthetic eIF4E1 gene for the model plant Arabidopsis thaliana with six amino acid changes known to be responsible for the pea's natural resistance and then introduced this gene into the plant. The scientists then verified that this new allele confers resistance to the plant against a Potyvirus isolate. The fact that this protein is functional allows it to be combined with other resistances in order to produce plants that are resistant to a large number of different Potyviruses, without any loss in yield.

This work demonstrates the effectiveness of gene design in establishing genetic resistance without harming plant development, through the knowledge of natural variability in a species such as cultivated peas. Furthermore, it shows that it is possible to apply this knowledge to another species, opening up prospects for the future development of a more sustainable broad-spectrum resistance through biotechnology.