Lytic Activity of Ubisch Bodies (Orbicles)

抄録

Ubisch bodies observed on the surface of tapetal cells in the anthers of Lilium henryi, are composed by the central electron-transparent part (core or nucleus) and by the marginal electron-dense zone. The central part is connected by a canal with the plasma membrane of the tapetal cells. ER participates at Ubisch bodies formation, it gathers electron-dense material, which causes their dilatation. During the formation of the electron-transparent nucleus of the Ubisch body, it is possible to observe a membrane on the surface of it. Clusters of dense material are apposed gradually on the surface of the nucleus, forming the dark marginal zone of the body. The Ubisch bodies are transported to the surface of the tapetal cells by the canals, they are connected with the plasma membrane and become lytically active. At the contact of the Ubisch bodies with the plasma membrane, lysis occurs of the surface parts of the cells. Basing on these observations, we consider Ubisch bodies to be a part of the lytic compartment of the tapetal cells. Differentiation of the Ubisch bodies and their lytic activity are simultaneously accompanied by intensive vacuolation of the tapetal cells, indicating relations of these two accurately programed processes.