CARBON-DIOXIDE ASSIMILATION IN UREA-TREATED WHEAT LEAVES

Application of 10 mM urea to the flag leaf of wheat plants enhanced in vivo urease activity severalfold. Photosynthetic rate was also increa sed considerably. There were significant differences in the leaf inter nal carbon dioxide (CO2) concentrations between the urea-treated and u ntreated leaves. The finding that carbon (C-14) was detected in the et hanol extract of the leaves fed with C-14-urea suggests that CO2 relea sed from urea is re-fixed by the leaves.