Isolation and characterization of a novelArabidopsis thatianamutant that requires a high concentration of boron

Abstract We isolated a novel Arabidopsis thaliana mutant line that requires high levels of boron (B) for normal growth. Line 8–21 was identified from ethyl methanesulfonate-mutagenized M2 population. When grown in medium containing 3 μm or less B in the form of boric acid, the fresh weights of aerial portions of the mutant were about a half of those of the wild type, but in that containing 300 μm B, the growth appeared normal. The mutant plants did not shown any difference in root growth from the wild-type plants in the range of B concentrations tested. When grown with 30 μm B, the B concentration in shoots of the line 8–21 was similar to that in the wild-type, suggesting that the mutant could not utilize B efficiently. Line 8–21 was not allelic to bor1-1 (Noguchi et al., Plant Physiol., 115, 901–906, 1997). A significant portion of F2 plants from the crosses between the wild-type and the mutant grew poorly on a low B media, suggesting segregation of the mutation.