Abstract
The culms of the mutant bc3 break crisply. As in another report by Hirano et al., we have succeeded in positional cloning of the causal gene BC3. The cellulose content of the culm of bc3 was reduced to 3/4 of the wild type, and the level of birefringence and calcoflour fluorescence were also reduced. Electron micrographs also confirmed reduction of the cell wall thickness in sclerenchyma and parenchyma cells. X ray analysis and negative staining of cellulose fibrils indicated that there are no apparent differences in these microstructures. The identified BC3gene's promoter was conjugated with GUS, and expression at tracheary elements of young culms and leaves and stele (central cylinder) of young roots were observed. Fusion protein of BC3 and GFP was found in the plasma membranes in the mature roots, but found in cytoplasm of the dividing BY-2 cells. Function of BC3 will be considered from these data.
