Abstract
A thymidine analog, 5-bromodeoxyuridine (BrdU) exerts peculiar effects on shoot redifferentiation of Arabidopsis thaliana. When administered during callus induction, BrdU at low concentrations promotes shoot redifferentiation and at high concentrations inhibits hypocotyl dedifferentiation. bro1 and bro2 are BrdU-resistant mutants isolated by screening with hypocotyl dedifferentiation as an index phenotype. Various phenomena that are normally suppressed by BrdU are also resistant to BrdU in these mutants. Meanwhile, these mutants show different sensitivities to 5-fluorodeoxyuridine (FdU). As judged from seedling growth, bro2 is resistant to FdU but bro1 is as FdU-sensitive as the wild type. This result might reflect that different mechanisms are responsible for BrdU resistance in these mutants. Recently, we have isolated 6 more BrdU-resistant mutants in the same way as described above. Initial characterization of their phenotypes, including sensitivity to FdU, is in progress. Here we report a new line-up of the BrdU-resistant mutants.
