Intracellular proliferation of clover yellow vein virus is unaffected by the recessive resistance gene cyv1 of Pisum sativum.

The pea cyv1 gene is a yet-to-be-identified recessive resistance gene that inhibits the infection of clover yellow vein virus (ClYVV). Previous studies confirmed that the cell-to-cell movement of ClYVV is inhibited in cyv1-carrying pea plants; however, the effect of cyv1 on viral replication remains unknown. In this study, we developed a new pea protoplast transfection method to investigate ClYVV propagation at the single-cell level. Using this method, we revealed that ClYVV accumulates to similar levels in both ClYVV-susceptible and cyv1-carrying pea protoplasts. Thus, the cyv1-mediated resistance would not suppress intracellular ClYVV replication.