STUDY ON THE ORIGIN OF PERIBACTEROID MEMBRANE OF BACTEROIDS IN VACUOLES IN VICIA SATIVA ROOT NODULES
箭舌豌豆根瘤液泡中细菌周膜来源的研究

The infected cells in young Vicia sativa root nodules possess a small amount of cytoplasm, their central parts are some larger vacuoles. Infection threads in host cytoplasm are often observed, they usually contain some bacteria and conti-nuousely release them to host cytoplasm, but the bacteroids only are to appear in host cytoplasm, never in vacuoles and the bacteroids all possess peribacteroid membranes which come from their infection thread membranes. Mature root nodules do not differ from young root nodules, they contain a large quantity of mature infected cells which possess abundant cytoplasm and many bacteroids, larger vacuoles have disappeared, some smaller vacuoles have appeared. Companying the development of infected cells, smaller vaculoes start fusion each other, finally they become into some large central vacuoles. When the central vacuoles further develope to certain degree, sorne bacteroids in host cytoplasm enter to central vacuoles by three formations, namely tonoplast endocytosis, fusion of tonoplast with peribacteroid membrane and tonoplast break, last one often companies with some host cytoplasm. Absorbute majority of bacteroids in central vacuoles do not possess peribacteroid membranes, only individual bacteroids have the structure and the better the peribacceroid membrane is the clearer the structure of the bacteroid is. The bacteroids with peribacteroid membrane often locate near the break places of tonoplast, they usually not in the central parts of the central vacuoles. Therefore, peribacteroid membrane may be originally possessive but not formed in vacuole.