title: Wide-range high-resolution transmission electron microscopy reveals morphological and distributional changes of endomembrane compartments during log to stationary transition of growth phase in tobacco BY-2 cells.
abstract: Rapid growth of plant cells by cell division and expansion requires an endomembrane trafficking system. The endomembrane compartments, such as the Golgi stacks, endosome and vesicles, are important in the synthesis and trafficking of cell wall materials during cell elongation. However, changes in the morphology, distribution and number of these compartments during the different stages of cell proliferation and differentiation have not yet been clarified. In this study, we examined these changes at the ultrastructural level in tobacco Bright yellow 2 (BY-2) cells during the log and stationary phases of growth. We analyzed images of the BY-2 cells prepared by the high-pressure freezing/freeze substitution technique with the aid of an auto-acquisition transmission electron microscope system. We quantified the distribution of secretory and endosomal compartments in longitudinal sections of whole cells by using wide-range gigapixel-class images obtained by merging thousands of transmission electron micrographs. During the log phase, all Golgi stacks were composed of several thick cisternae. Approximately 20 vesicle clusters (VCs), including the trans-Golgi network and secretory vesicle cluster, were observed throughout the cell. In the stationary-phase cells, Golgi stacks were thin with small cisternae, and only a few VCs were observed. Nearly the same number of multivesicular body and small high-density vesicles were observed in both the stationary and log phases. Results from electron microscopy and live fluorescence imaging indicate that the morphology and distribution of secretory-related compartments dramatically change when cells transition from log to stationary phases of growth.
authors.affiliation: RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045 Japan toyooka@riken.jp.
authors.forename: Kiminori
authors.initials: K
authors.lastname: Toyooka
authors.affiliation: RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045 Japan.
authors.forename: Mayuko
authors.initials: M
authors.lastname: Sato
authors.affiliation: Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha, Kashiwa, Chiba, 277-8562 Japan.
authors.forename: Natsumaro
authors.initials: N
authors.lastname: Kutsuna
authors.affiliation: Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha, Kashiwa, Chiba, 277-8562 Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Higaki
authors.affiliation: Faculty of Science, Japan Women's University, Bunkyo-ku, Tokyo, 112-8681 Japan.
authors.forename: Fumie
authors.initials: F
authors.lastname: Sawaki
authors.affiliation: RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045 Japan.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Wakazaki
authors.affiliation: RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045 Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Goto
authors.affiliation: Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha, Kashiwa, Chiba, 277-8562 Japan.
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Hasezawa
authors.affiliation: Faculty of Science, Japan Women's University, Bunkyo-ku, Tokyo, 112-8681 Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Nagata
authors.affiliation: Laboratory of Plant Nutrition, Faculty of Agriculture, Kyushu University, Hakozaki 6-10-1, Higashi-ku, Fukuoka, 812-8581 Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Matsuoka
mesh_terms: D002451:Cell Compartmentation; D002473:Cell Wall / Q000378:metabolism / Q000648:ultrastructure; D002478:Cells, Cultured; D017930:Genes, Reporter; D006056:Golgi Apparatus / Q000378:metabolism / Q000648:ultrastructure*; D046529:Microscopy, Electron, Transmission / Q000379:methods*; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D021381:Protein Transport; D011993:Recombinant Fusion Proteins; D014026:Nicotiana / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure*; D021601:trans-Golgi Network / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D011993:Recombinant Fusion Proteins
keywords: Electron microscopy; Golgi stack; High-pressure freezing; Tobacco BY-2 cells; Vesicle cluster; trans-Golgi network