Host: The Japan Radiation Research Society
Co-host: Asian Association for Radiation Research
Ultraviolet-B (UVB) radiation can damage plant, decreasing growth and productivity. In our over 10 year's field experiments in a northeast of Japan, elevated UVB radiation markedly influenced growth and grain development such as grain size, total nitrogen content, and grain of storage protein composition in rice. We found that the sensitivity to elevated UVB radiation in rice varies widely among cultivars. Such a difference in UVB sensitivity in rice was controlled by at least three major recessive genes. Our previous data also indicated that the photorepair ability of cyclobutane pyrimidine dimers (CPDs) are significantly higher in UV-resistant rice cultivars than in UV-sensitive cultivars, and that the difference in the CPD photorepair ability resulted from a structure/function alteration of photolyase due to the alteration of one or two amino acids in CPD photolyase. Furthermore, a linkage analysis in populations derived from UV-hypersensitive indica cultivar Surjamkhi and UV-resistant japonica cultivar Sasanishiki showed that UVB sensitivity is a quantitative inherited trait and that the CPD photolyase locus is tightly linked with a quantitative trait locus (QTL) that explains a major portion of the genetic variation for this trait. These results suggest that spontaneously occurring mutations in the CPD photolyase gene in rice cause different degrees of sensitivity to UVB. In this meeting, we discuss current status and perspective of UVB and plant research.
