There is at present a surge of interest in plant biochemistry, as the gaps in our knowledge are seen as a major impediment to progress, especially in such areas as genetic engineering. Techniques for the transfer of genes in plants are well advanced, and the question has become not how to transfer the genes, but which genes should be moved. To be able to answer this question, it is necessary to know the pathways, and to have purified and characterized the enzymes that catalyse these pathways. In the cases that have been studied, fundamental differences between the biochemistry of plants and...