LONG-TERM METABOLISM OF (3/-)-ABSCISIC-2-C-14 ACID BY APPLE SEEDS

Apple seeds soaked in a solution of [±]-[2-14C]abscisic acid for up to 70 d formed phaseate and the epimeric dihydrophaseates and all four acids were converted into alkali-hydrolysable conjugates. This metabolism occurred in the husks and in the embryos. Both parts of untreated control seeds contained the four acids and their conjugates. In addition to these characterized metabolites, a number of other, labelled, acidic products were isolated from the seeds. 14CO2 was evolved from unsterilized seeds but not from surface-sterilized ones. Bacterial cultures isolated from soil and rotting fruit metabolized [14C]ABA to a range of compounds, but not to phaseic or the dihydro-phaseic acids. A new, acidic conjugate of ABA is described. © 1979 Oxford University Press.