xanthoxin造句

• "' Xanthoxin "'is an intermediate in the biosynthesis of the plant hormone abscisic acid.
• It is produced by the dehydrodgenation of xanthoxin by xanthtoxin dehydrogenases, which is an NAD + dependent short-chain dehydrogenas, followed by selective oxidation by abscisic aldehyde oxygenase.
• Abscisic acid ( ABA ) is an isoprenoid plant hormone, which is synthesized in the plastidal 2-" C "-methyl-D-erythritol-4-phosphate ( MEP ) pathway; unlike the structurally related sesquiterpenes, which are formed from the mevalonic acid-derived precursor farnesyl diphosphate ( FDP ), the C 15 backbone of ABA is formed after cleavage of C 40 carotenoids in MEP . Zeaxanthin is the first committed ABA precursor; a series of enzyme-catalyzed epoxidations and isomerizations via violaxanthin, and final cleavage of the C 40 carotenoid by a dioxygenation reaction yields the proximal ABA precursor, xanthoxin, which is then further oxidized to ABA . via abscisic aldehyde.