title: Localization of glutamine synthetase isoforms in hair cells of Azolla leaves.
abstract: Immunoelectron microscopy and a quantitative analysis of immunogold labeling of a glutamine synthetase (GS; EC 6.3.1.2) revealed that, in mesophyll cells of mature leaves of Azolla filiculoides, almost all GS was present in chloroplasts. By contrast, in hair cells, abundant labeling of GS was observed both in chloroplasts and in the cytoplasm. In hair cells of cyanobiont-free plants, the labeling of GS of both chloroplasts and cytoplasm was very weak compared to that of cyanobiont-containing plants. The findings suggest that hair cells play an important role in the assimilation of ammonia released by the cyanobiont.
authors.affiliation: Research Institute for Advanced Science and Technology, Osaka Prefecture University, Gakuen-cho 1-2, Sakai, Osaka, 599-8570 Japan. uheda@riast.osakafu-u.ac.jp
authors.forename: Eiji
authors.initials: E
authors.lastname: Uheda
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Maejima
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Shiomi
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism / Q000648:ultrastructure; D003593:Cytoplasm / Q000378:metabolism / Q000648:ultrastructure; D029624:Ferns / Q000201:enzymology*; D005974:Glutamate-Ammonia Ligase / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D005973:Glutamine / Q000096:biosynthesis; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D046529:Microscopy, Electron, Transmission; D018515:Plant Leaves / Q000201:enzymology* / Q000235:genetics / Q000648:ultrastructure
chemical_list: D007527:Isoenzymes; D005973:Glutamine; D000641:Ammonia; D005974:Glutamate-Ammonia Ligase