Immuno-gold localisation of arabinogalactan protein in the developing style of Nicotiana alata
Sedgley, M.C.arke, A.
Nordic Journal of Botany 5: 591-598
Arabinogalactan-protein was localized ultrastructurally in the transmitting tissue of the Nicotinana alata Link and Otto style from the bud stage to anthesis using monoclonal antibody directed to terminal .alpha.-L-arabinosyl residues followed by goat antimouse IgG linked to 20 nm gold particles. Gold particles were localized on the Golgi apparatus, multivesicular bodies, cell wall and intercellular matrix with the highest concentration over multivesicular bodies. During flower development there was an increase in the total number of gold particles with a relative decrease on the multivesicular bodies and an increase on the intercellular matrix. There was also an increase during development in the proportion of intercellular matrix relative to all other components of the transmitting tissue. Vesiculation of the endoplasmic reticulum and the production of cup-shaped vesicles by the Golgi bodies were observed during development. It is concluded that secretion of arabinogalactan-protein from the intracellular to the extracellular location occurs via multivesicular bodies produced by the Golgi apparatus and possibly the endoplasmic reticulum.