Abstract
There is a difference in the inhibitory effects to supplemental ultraviolet-B (UV-B) among Japanese rice (Oryza sativa L.) cultivars. The cultivar Sasanishiki is resistant while the cultivar Norin 1 is less resistant, although these two cultivars are closely related. We found that the cyclobutane pyrimidine dimer (CPD) photolyase activities is greater in Sasanishiki than Norin 1. Moreover, the 126th amino acid of CPD photolyase (full length 506 amino acids) of Sasanishiki is glutamine, while that of Norin 1 is arginine. In this study, we determined the sequences of CPD photolyase gene and CPD photolyase activity of progenitors of Sasanishiki and Norin 1, and of several other Japanese rices. Consequently we found that Japanese rice cultivars can be divided into the two different types: One is Sasanishiki-type, the other being Norin-type.
