Abstract
In Arabidopsis thaliana, mutants defective in ribosomal proteins often develop leaves with pointed shape. We have isolated more than 20 mutants exhibiting such a phenotype. We found that in the asymmetric leaves1 (as1)/as2 backgrounds, which show a weak adaxial defect, some of these mutations strongly enhanced the adaxial defect. Further experiments suggested, however, that not all of pointed-leaves mutants were able to enhance the adaxial defect. To elucidate such differential effects, we cloned the responsible genes from these pointed-leaves mutants. So far, we found that mutants with strong enhancing effects were defective in either a constituent of the 60S subunit or a protein involved in ribosome biogenesis. The cloning of responsible genes from mutants without enhancing effects is in progress. We will discuss possible mechanisms on ribosome-mediated differential gene expression
