Treatment of ‘Paul's Scarlet rose (
Rosa sp.) cell suspensions with β-D-glucosyl Yariv phenylglycoside (β-D-Glc)
3, a chromophoric molecule that selectively binds arabinogalactan-proteins (AGPs), caused inhibition of cell growth in a concentration-dependent
manner, with complete inhibition of growth occurring at 50 μM (β-D-Glc)
3 in the culture medium. Growth was not inhibited by either α-D-galactosyl or β-D-mannosyl Yariv phenylglycosides which do
not bind AGPs. Staining of cells with fluorescein diacetate indicated that (β-D-Glc)
3 did not affect cell viability. Upon transfer of 50 μM (β-D-Glc)
3-treated cells to control conditions, cell growth recovered with a time-course similar to that of control cells. Cell sizes
in control and (β-D-Glc)
3-treated cultures were similar, indicating that the mechanism of growth inhibition by (β-D-Glc)
3 involved suppression of cell division. Two different analyses of (β-D-Glc)
3-treated cells both showed that approximately 95% of the bound (β-D-Glc)
3 was in the cell wall. Molecules that bound (β-D-Glc)
3 were extracted from the cell wall and were identified as AGPs, as judged by their carbohydrate and amino acid compositions.
Key words Arabinogalactan-protein - Cell proliferation - Cell wall - (β-d-glucosyl)3 Yariv phenylglycoside - Plasma membrane -
Rosa