Figure 1.

Loliose localization and biosynthesis pathway in perennial ryegrass. A, Loliose repartition in the different tissues of perennial ryegrass. Values are mean of three replicates and indicate the loliose concentration (milligrams per gram dry weight). B, HPAEC-PAD profiles from incubations of desalted crude extract from leaf sheaths of perennial ryegrass with 50 mm Suc and either 5 mm UDP-Gal (top panel) or 5 mm galactinol (middle panel) at pH 8.5 for 24 h. The bottom panel show a mixed standard with myoinositol (My), mannitol (Ma), Glc, Fru, Suc, raffinose (Raf), and loliose (Lol). 1-K, 1-Kestotriose. C, pH-dependent activity profile of loliose synthase assayed with 50 mm Suc and 5 mm UDP-Gal. The enzyme activity was assayed at different pH from 5.5 to 9.0 using the following buffer solutions: pH 5.5 to 6.7, MES buffer; pH 6.7 to 8, HEPES buffer; and pH 8 to 9, HEPBS buffer. Vertical bars indicate ± se (n = 3).