Summary
Slight transport of 14C-valine fed to leaves of Datura stramonium L. was found to occur, mainly to fruits but also to roots. The intensity of translocation was affected by the age of the fed leaf, the age of the fruit, the duration of the experiment and the illumination of the plant. Mature leaves of plants kept in darkness do not export 14C-valine in measurable amounts. The inhibition of export in darkness probably occurs in the leaf blade. The fed 14C-valine is metabolized mainly to sucrose, glutamic acid and leucine. Among the amino acids of the proteins, valine carries the highest label, followed by leucine.