A cDNA Clone for 5-Aminolevulinic Acid Dehydratase from Tomato (Lycopersicon esculentum Mill.)

摘要

ALAD (EC 4.2.1.24) catalyzes the condensation of two ALA molecules to form porphobilinogen, a monopyrrole precursor of both heme and Chi (Richards, 1993). In plants, ALAD is synthesized in the cytoplasm and subsequently is associated exclusively withplastids, even in tissues in which synthesis of nonplastic heme is predominant (Smith, 1988). Synthesis of ALAD is amplified by the action of phytochrome (Tchuinmogne et al., 1989), and ALAD may interact with an ALA precursor (4,5-dioxovalerate) to limit Chl synthesis in light (Kotzabasis et al., 1989). We are investigating a possible regulatory role of ALAD in Chl synthesis during tomato (Lycopersicon esculentum Mill.) fruit development and ripening.