Regulation of Chlorophyll Synthesis in Plant Cells: Biochemical and genetic approaches will be used to study in Chlamydomonas the regulation of synthesis of delta-aminolevulinic acid, the first committed compound in synthesis of the porphyrin ring of chlorophyll. The enzyme that ligates glutamate to its transfer RNA has been purified. The remaining two enzymes of the pathway will be purified and the genes for all three enzymes will be cloned and sequenced. Understanding the biosynthesis of delta-aminolevulinic acid and its regulation is essential for the understanding of the regulation of chlorophyll biosynthesis and the assembly of the photosynthetic membranes in plant cells. Because of the known similarities between Chlamydomonas and higher plants not only the knowledge but also the genes may be transferable and thus available to genetic engineering for increasing plant growth efficiency
