TY - JOUR AU - Mount, D W AB - Abstract A genetic screen for mutants of Arabidopsis that are hypersensitive to UV light was developed and used to isolate a new mutant designated uvh1. UV hypersensitivity in uvh1 was due to a single recessive trait that is probably located on chromosome 3. Although isolated as hypersensitive to an acute exposure to UV-C light, uvh1 was also hypersensitive to UV-B wavelengths, which are present in sunlight that reaches the earth's surface. UV-B damage to both wild-type and uvh1 plants could be significantly reduced by subsequent exposure of UV-irradiated plants to photoreactivating light, showing that photoreactivation of UV-B damage is important for plant viability and that uvh1 plants are not defective in photoreactivation. A new assay for DNA damage, the Dral assay, was developed and used to show that exposure of wild-type and uvh1 plants to a given dose of UV light induces the same amount of damage in chloroplast and nuclear DNA. Thus, uvh1 is not defective in a UV protective mechanism. uvh1 plants were also found to be hypersensitive to ionizing radiation. These results suggest that uvh1 is defective in a repair or tolerance mechanism that normally provides plants with resistance to several types of DNA damage. This content is only available as a PDF. © 1994 by American Society of Plant Biologists This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model) TI - Isolation of uvh1, an Arabidopsis mutant hypersensitive to ultraviolet light and ionizing radiation. JF - The Plant Cell DO - 10.1105/tpc.6.2.227 DA - 1994-02-01 UR - https://www.deepdyve.com/lp/oxford-university-press/isolation-of-uvh1-an-arabidopsis-mutant-hypersensitive-to-ultraviolet-N0xtlXPUWb SP - 227 EP - 235 VL - 6 IS - 2 DP - DeepDyve ER -