KU80, a key factor for non-homologous end-joining, retards geminivirus multiplication.

KU80 is well-known as a key component of the non-homologous end-joining pathway used to repair DNA double-strand breaks. In addition, the KU80-containing DNA-dependent protein kinase complex in mammals can act as a cytoplasmic sensor for viral DNA to activate innate immune response. We have now, to our knowledge for the first time, demonstrated that the speed of a systemic infection with a plant DNA geminivirus in Arabidopsis thaliana is KU80-dependent. The early emergence of Euphorbia yellow mosaic virus DNA was significantly increased in ku80 knockout mutants compared with wild-type sibling controls. The possible impact of KU80 on geminivirus multiplication by generating non-productive viral DNAs or its role as a pattern-recognition receptor against DNA virus infection is discussed.