Key Points
- Begomoviruses pose a significant threat to global pepper production, resulting in crop losses of up to 100% in affected fields.
- Kindai University scientists combined pepy-1 and Pepy-2 genes, creating a dual defense against complex virus infections.
- Gene pyramiding significantly reduced disease symptoms and viral DNA in mixed infection scenarios.
- Pepy-2 offers broad protection, while Pepy-1 targets specific regional viruses; together, they provide robust coverage.
A Japanese research team has developed a groundbreaking approach to combat begomoviruses—plant pathogens that cause yellow leaf curl disease and devastate pepper crops globally. These viruses, transmitted by whiteflies, can wipe out entire harvests across Asia, Africa, and the Americas, resulting in annual losses of billions.
Led by Dr. Sota Koeda from Kindai University, the team published their findings in Plant Disease. They demonstrated that combining two resistance genes, pepy-1 and Pepy-2, in a single pepper plant offers broad-spectrum protection against even the most aggressive viral infections, including mixed infections from both Old World and New World begomoviruses.
While previous efforts to breed virus-resistant peppers relied on single resistance genes, they often failed under mixed-virus conditions. In this study, the team used advanced inoculation techniques to test the performance of both genes individually and in combination. Pepy-1, a recessive gene, regulates virus control through a protein called Pelota, whereas Pepy-2, a dominant gene, utilizes RNA-dependent RNA polymerase to silence viral genes.
Their experiments revealed that the homozygous combination of both genes significantly reduced viral DNA accumulation and disease severity. This “gene pyramiding” approach created a synergistic effect—overcoming the limitations of using either gene alone.
Notably, Pepy-2 was effective against a broader range of begomoviruses, especially those from the Americas, such as pepper huasteco yellow vein virus and pepper golden mosaic virus, whereas Pepy-1 was more effective against Old World viruses.
“This strategy could revolutionize how we breed crops for viral resistance,” said Dr. Koeda. The success of this dual-gene approach holds promise for sustainable pepper production, particularly in virus-prone regions such as Mexico, Indonesia, Turkey, and India, which collectively contribute to the 42 million tons of peppers grown globally each year.
Dr. Koeda added that the team is now exploring how this gene-stacking method could be applied to other vegetables, potentially transforming viral resistance strategies across multiple crops.
