AGROBACTERIUM-TUMEFACIENS TRANSFORMATION OF THE RADIATION HYPERSENSITIVE ARABIDOPSIS-THALIANA MUTANTS UVH1 AND RAD5

The Arabidopsis thaliana mutants uvh1 and rad5, originally identified as radiation hypersensitive, were reported to be deficient in T-DNA in tegration based on the relative efficiencies of stable transformation and T-DNA transfer, We reassessed these mutants for susceptibility to transformation by Agrobacterium tumefaciens. The mutant rad5 showed a significant reduction in the efficiency of transient as well as stable transformation, compared with its wild-type progenitor. These data in dicate that rad5 is blocked at a step in the transformation process pr ior to T-DNA integration. We additionally found, using both an in vitr o root inoculation and an in vivo flower bolt inoculation assay, that the mutant uvh1 is as susceptible to A, tumefaciens-mediated transform ation as is its wild-type progenitor, C10.