Abstract
qUVR-10 shows the largest allelic difference among six QTLs controlling UVB-resistance, which have been detected by QTL analysis using backcross inbred lines derived from a cross between, Nipponbare (resistant) and Kasalath (sensitive). Plants with Kasalath allele at qUVR-10 were more sensitive to UVB compared with those with Nipponbare allele. Fine-scale mapping localized qUVR-10 to a 27-kb locus containing cyclobutane pyrimidine dimer (CPD) photolyase. Analysis of CPDs photorepair in the plants in which recombination was occurred in flanking region of qUVR-10 indicated that the genomic region responsible for ability of CPDs photorepair was same as that of qUVR-10. Sequence comparison between Nipponbare and Kasalath CPD photolyase gene revealed one base substitution in the conserved region of photolyase, resulting an amino acid substitution. These results strongly suggest that qUVR-10 encodes CPD photolyase and the amino acid substitution in photolyase causes reduction of photorepair capacity in the plants with Kasalath allele at qUVR-10.
