Effects of light and phytohormones on the expression of cucumber ferrochelatases

摘要

Chlorophylls (Chls) and hemes are major tetrapyrrole compounds in photosynthetic organisms, playing essential roles in such processes as photosynthesis and respiration. In higher plants, these compounds are synthesized from glutamyl-tRNA via 5-aminolevulinic acid (ALA), a linear five-carbon molecule. The branch point of the biosynthetic pathway of heme and Chls is protoporphyrin IX, a closed-macrocycle without chelated ions. Ferrochelatase catalyzes the chelation of ferrous ion into the protoporphyrin IX to form protoheme, while Mg-chelatase catalyzes the insertion of magensium ion to subsequent formation of Chls.