Abstract
To investigate UVB-response mechanisms in higher plants, we have isolatd and been analysing a series of UVB-sensitive mutants in Arabidopsis. For example, suv1 (for sensitive to UV1; now renamed rev3-1) has a defect in an error-prone translesion synthesis (Sakamoto et al., 2003) whereas suv3 is defective in the NER system (Vo et al., unpublished). Here we report another mutant suv2 whose seedlings are hypersensitive to UV-B, γ-ray and mitomycin C. The suv2 mutation was mapped on the bottom of chromosome 5 and the Southern blots using P1 clones detected a chromosome rearrangement including several duplications and insertions in suv2. The gene disrupted by the insertion, MRA19.1, has no significant homology to any previously known DNA-repair genes. We hypothesize that the MRA19.1 is a novel gene which is involved in the damage-repair or damage-tolerance pathways in higher plants.
