Abstract
Ultraviolet (UV) radiation induces pyrimidine dimmers, which cause mutation at dipyrimidine site on DNA. Two types of pyrimidine dimers, cyclobutane pyrimidine dimer (CPD) and (6-4) photoproduct, are known and both of them inhibit growth of organisms. Plants grown under the solar radiation are continuously exposed to high dose of UV. Some species of plants are sensitive to UV. If the sensitivity is due to DNA damages induced by UV, increased efficiency of the repair of pyrimidine dimers may lead to UV resistance of plants. Approximately 70% of UV induced pyrimidine dimers are CPD. Spinach CPD photolyase gene was introduced into wild type Arabidopsis thaliana to investigate the enhanced resistance to UV. The CPD photolyase gene was inserted in the down stream of CaMV 35S promoter on the vector pBI121. We introduced this construct in Arabidopsis mediated by Agrobacterium by the floral dip method and obtained several transgenic plants. The incorporation of the gene into plant genome was determined by PCR and the expression of the gene by RT-PCR. The rate of the growth of transgenic Arabidopsis irradiated with UV-B was higher than that of wild type. These results show that growth inhibition by UV-B was diminished by an addition of CPD photolyase gene, suggesting the possibility to improve the UV sensitivity of plant by introducing DNA repair gene.
