Abscisic Acid Metabolism by Source and Sink Tissues of Sugar Beet

Abstract
The fate of exogenously applied, labeled abscisic acid (±)-(ABA) was followed in source leaves and taproot sink tissues of sugar beet (Beta vulgaris cv AH-11). The objective was to determine if differential pathways for ABA metabolism exist in source and sink tissues. Tissue discs were incubated for up to 13 hours in a medium containing 1 micromolar labeled ABA. At various time intervals, samples were taken for metabolite determination by reverse-phase high performance liquid chromatography. The labeled metabolites were identified by retention times using an online scintillation counter.