Cell wall polysaccharides in differentiating anthers and pistils of Lolium perenne

We are presenting the pattern of distribution of several carbohydrate epitopes, which constitute an important component of cell walls, within the anthers and pistils of a monocot grass species, perennial ryegrass (Lolium perenne L.). The results of immunocytochemical studies revealed that the flower organs are rich in (1 -> 3, 1 -> 4)-beta-D-glucans and possess surprisingly high amounts of methylesterified pectic domains that bind JIM7 antibody and pectin side chains rich in (1 -> 4)-beta-D-galactose residues which react with LM5 antibody. The presence of arabinogalactan protein epitopes binding JIM13 is restricted to microspores and ovule integuments. The results are discussed in terms of possible functions of cell wall polysaccharides and arabinogalactan proteins in the differentiation of flower organs.