EFFECTS OF YARIV PHENYLGLYCOSIDES ON ROSA CELL-SUSPENSIONS - EVIDENCE FOR THE INVOLVEMENT OF ARABINOGALACTAN-PROTEINS IN CELL-PROLIFERATION

Treatment of 'Paul's Scarlet rose (Rosa sp.) cell suspensions with beta-D-glucosyl Yariv phenylglycoside (beta-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 mu M (beta-D-Glc)(3) in the culture medium. Growth was not inhibited by either alpha-D-galactosyl or beta-D-mannosyl Yariv phenylglycosides which do not bind AGPs. Staining of cells with fluorescein diacetate indicated that (beta-D-Glc)(3) did not affect cell viability. Upon transfer of 50 mu M (beta-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 (beta-D-Glc)(3)-treated cultures were similar, indicating that the mechanism of growth inhibition by (beta-D-Glc)(3) involved suppression of cell division. Two different analyses of (beta-D-Glc)(3)-treated cells both showed that approximately 95% of the bound (beta-D-Glc)(3) was in the cell wall. Molecules that bound (beta-D-Glc)(3) were extracted from the cell wall and were identified as AGPs, as judged by their carbohydrate and amino acid compositions.