METABOLISM OF (+)-ABSCISIC ACID TO (+)-7'-HYDROXYABSCISIC ACID BY BROMEGRASS CELL-CULTURES

7'-Hydroxyabscisic acid was isolated from the medium of smooth bromegrass (Bromus inermis Leyss.) cell suspension cultures supplied with either (+/-)- or natural (+)-abscisic acid, and the identity of the metabolite confirmed by H-1 NMR. Analysis of the methyl esters of the metabolite by chiral HPLC showed only the (+) enantiomer of 7'-hydroxyabscisic acid to be present in the medium of cultures fed (+)-abscisic acid. In cultures treated with (+/-)-abscisic acid, the (-) enantiomer of the metabolite is formed from the (-)-abscisic acid component of the racemic mixture supplied.