Abstract
Apoplastic fluid (AP) was collected by a pressure chamber method reported by Nozaki et al. (2003). Acid hydrolysis of AP released low level of Fuc, Ara, Xyl, Man, and Gal, and relatively high level of Rha and Glc. Ratios of Ara to Gal, and Rha to Glc were about one. Concentration of these sugars obtained at 1 MPa showed diurnal rhythm. We attempted to identify the compounds containing these sugars. Arabinogalactan protein (AGP) concentration obtained at 0 MPa, 1 MPa AP and symplastic fluid (SY) was determined with β-glucosyl Yariv reagent. Concentrations of AGP were 0.27 at 0 MPa, 0.04 at 1 MPa and 0.31 mg/ml for SY. The amount of AGP in each fluid corresponded to those of Ara and Gal, suggesting that Ara and Gal in AP were mainly derived from of AGP.
