Significance UV wavelengths of sunlight cause damage to genomic DNA in all organisms, including plants. Although UV photoproducts are known to be removed from DNA through the process of nucleotide excision repair in a wide variety of organisms, ranging from bacteria to humans, the mechanism of this repair process in plants has never been examined. Here, using a highly sensitive DNA repair assay that we developed to monitor UV photoproduct repair in vivo, we found that plants remove UV photoproducts from their genomic DNA through a dual-incision mechanism that is nearly identical to that of humans and other eukaryotes.