Molecular and Enzymatic Characterization of Flavonoid 3'-Hydroxylase of <i>Malus</i> × <i>domestica</i>.

ABSTRACT: Malus × domestica (apple) accumulates particularly high amounts of dihydrochalcones in various tissues, with phloridzin (phloretin 2'-O-glucoside) being prevalent, although small amounts of 3-hydroxyphloretin and 3-hydroxyphloridzin are also constitutively present. The latter was shown to correlate with increased disease resistance of transgenic M. × domestica plants. Two types of enzymes could be involved in 3-hydroxylation of dihydrochalcones: polyphenol oxidases or the flavonoid 3'-hydroxylase (F3'H), which catalyzes B-ring hydroxylation of flavonoids. We isolated two F3'H cDNA clones from apple leaves and tested recombinant Malus F3'Hs for their substrate specificity. From the two isolated cDNA clones, only F3'HII encoded a functionally

SUBMITTER: Weissensteiner J 

PROVIDER: S-EPMC8469728 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature