Localization of Arabinogalactan Proteins in the Cell Walls of Developing Ovule in Strawberry (Fragaria X Ananassaduch.)

The aim of the study was to investigate changes in the localization of arabinogalactan proteins (AGPs) during ovule development in Fragaria x ananassa Duch. cv. ‘Mount Everest’. For the first time, the localization of AGPs was studied in a hybrid Fragaria x ananassa, which is a facultative apomict. The AGP epitopes were revealed with the use of JIM13 mAb after immune cyto chemical reaction and immune gold labeling. The fluorescence after immune cyto chemical reaction and gold particles indicated the presence of AGPs, which changed during the consecutive stages of ovule development. AGPs were localized in the walls of nucellus cells lying on the possible route of pollen tube growth, functional megaspore, and embryo sac. Such a distribution of AGPs resembles the localization of these proteins in plants that reproduce in the amphimiticmode. Moreover, the AGPs were observed in the cell walls of the embryo. In addition to the wall of the embryo sac, they were also present in the cytoplasm of the egg cell, near the secondary nuclei in the central cell, and in the endosperm. In the nucellus cells, AGPs were observed in the area of starch grains. The possible functions in Fragaria x ananassa of AGPs are discussed.