Five rice ( Oryza sativa L.) cultivars, widely planted in South China, were grown in greenhouse with or without supplemental UV_B radiation at level of 13.6 kJ·m -2 ·d -1 . After 15 day_UV_B treat...Five rice ( Oryza sativa L.) cultivars, widely planted in South China, were grown in greenhouse with or without supplemental UV_B radiation at level of 13.6 kJ·m -2 ·d -1 . After 15 day_UV_B treatment, significant intraspecific differences were observed in plant height, photosynthetic rate and total biomass. Based on the total biomass accumulation, cultivar “Tesanai” was found to be the most sensitive, and cultivar “Luhuangzhan” was the most tolerant species to UV_B radiation. UV_B induced cyclobutane pyrimidine dimer (CPD) in rice DNA were quantified by ELISA with specific monoclonal antibody. CPD accumulations in DNA extracted from 5 rice cultivars were remarkably increased by UV_B radiation, and it was confirmed that there was a strong positive correlation between CPD accumulation and the inhibition of total biomass. Photorepair was proved to be the predominant mode of CPD repair in UV_B irradiated rice. Light_dependent removal of CPD was very fast as compared with dark repair. Different levels of CPD accumulation among rice cultivars were related with different capacity of CPD photorepair. Capacity of light_dependent CPD removal may play an important role in UV_B resistance of rice.展开更多
文摘Five rice ( Oryza sativa L.) cultivars, widely planted in South China, were grown in greenhouse with or without supplemental UV_B radiation at level of 13.6 kJ·m -2 ·d -1 . After 15 day_UV_B treatment, significant intraspecific differences were observed in plant height, photosynthetic rate and total biomass. Based on the total biomass accumulation, cultivar “Tesanai” was found to be the most sensitive, and cultivar “Luhuangzhan” was the most tolerant species to UV_B radiation. UV_B induced cyclobutane pyrimidine dimer (CPD) in rice DNA were quantified by ELISA with specific monoclonal antibody. CPD accumulations in DNA extracted from 5 rice cultivars were remarkably increased by UV_B radiation, and it was confirmed that there was a strong positive correlation between CPD accumulation and the inhibition of total biomass. Photorepair was proved to be the predominant mode of CPD repair in UV_B irradiated rice. Light_dependent removal of CPD was very fast as compared with dark repair. Different levels of CPD accumulation among rice cultivars were related with different capacity of CPD photorepair. Capacity of light_dependent CPD removal may play an important role in UV_B resistance of rice.
