Abstract
The amount of Rubisco in leaves is largely affected by nitrogen nutrition during leaf expansion. The purpose of this study was to examine the relationship between nitrogen nutrition and gene expression of Rubisco in rice leaves. Rice plants (Oryza sativa L. cv. Notohikari) were grown with different levels of nitrogen supply (sufficient, control and deficient) from the emergence of the 8th leaves. The levels of mRNAs of rbcS and rbcL responded to the changes in the nitrogen levels quickly and reached the highest values one day after the treatments in the 8th leaves, irrespective of the treatments. The levels of rbcS and rbcL DNA, however, did not increase as the same extent as the mRNAs did, indicating that the regulation of the levels of mRNAs of rbcS and rbcL in expanding leaves of rice under different levels of nitrogen supply includes some important factors other than the template levels.
