The Compartmentation of Abscisic Acid and β-d-Glucopyranosyl Abscisate in Mesophyll Cells

Abstract

β-d-Glucopyranosyl abscisate (ABA-GE) is synthesized in Xanthium strumarium L. leaves during water stress. Following recovery from stress, the amount of ABA-GE does not decline. These observations led to the hypothesis that ABA-GE is sequestered in the vacuole where it is metabolically inert. The localization of abscisic acid (ABA) and ABA-GE was investigated by a dimethyl sulfoxide (DMSO) compartmentation method and by direct isolation of vacuoles.