RAD5a and REV3 function in two alternative pathways of DNA-damage tolerance in Arabidopsis

► Arabidopsis rad5a and rev3 mutations are synergistic to MMS-induced DNA damage. ► It supports a two-branch DNA-damage tolerance model in higher eukaryotes. ► Their genetic interactions to other types of DNA damage are different. ► Compared to yeasts, plants prefer to utilize TLS over error-free bypass.