Distribution of arabinogalactan proteins during microsporogenesis in the anther of Bellis perennis L. (Asteraceae)

Abstract

Using monoclonal antibodies (mAbs) JIM13, JIM15 and MAC207, we investigated the temporal and spatial distribution of some arabinogalactan protein (AGP) epitopes in cells of the Bellis perennis L. anther at different developmental stages. AGP epitopes recognized by JIM13 were detected in the protoplasts of tapetal cells, dividing microsporocytes, and microspores; AGP epitopes recognized by JIM15 were present in the cytoplasm of tapetal cells only at the stage with tetrads of microspores in the anther loculus. AGP epitopes recognized by MAC207 were present in the cells of different somatic tissues of the flower bud, but after asymmetric mitosis in the microspore they appeared abundantly in the protoplasts of immature pollen and were still present in mature pollen grains. Callose, revealed by mAb, appeared at the same stage of microsporocyte division as AGPs labeled with JIM13 and JIM15. We discuss the differences in callose and AGP localization and the possible role of the latter during anther development.