Photoregulation of DMA Photolyases in Broom Sorghum Seedlings

Abstract— Using dark-grown 3 day-old Sorghum bicolor seedlings, photorepair of cyclobutane pyrimidine dimers (CPD) by CPD-photoIyase and pyrimidine-(6–4)pyrimidinone photoproducts ([6–4]PP) by [6–4]PP-photolyase was studied in vivo and in vitro. The two types of DNA photoproducts were measured with specific monoclonal antibodies. Sorghum seedlings have different photorepair enzymes for CPD and [6–4]PP. The CPD-photolyase was found to be increased in response to light with maximal efficiency in the UVA/blue spectral range, whereas [6–4]PP-photolyase was not influenced by light.