title: The ER body, a novel endoplasmic reticulum-derived structure in Arabidopsis.
abstract: Plant cells develop various endoplasmic reticulum (ER)-derived structures with specific functions. The ER body, a novel ER-derived compartment in Arabidopsis, is a spindle-shaped structure (approximately 10 microm long and approximately 1 microm wide) that is surrounded by ribosomes. Similar structures were found in many Brassicaceae plants in the 1960s and 1970s, but their main components and biological functions have remained unknown. ER bodies can be visualized in transgenic Arabidopsis expressing the green fluorescent protein with an ER-retention signal. A large number of ER bodies are observed in cotyledons, hypocotyls and roots of seedlings, but very few are observed in rosette leaves. Recently nai1, a mutant that does not develop ER bodies in whole seedlings, was isolated. Analysis of the nai1 mutant reveals that a beta-glucosidase, called PYK10, is the main component of ER bodies. The putative biological function of PYK10 and the inducibility of ER bodies in rosette leaves by wound stress suggest that the ER body functions in the defense against herbivores.
authors.affiliation: Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502 Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Matsushima
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Kenji
authors.initials: K
authors.lastname: Yamada
authors.forename: Tomoo
authors.initials: T
authors.lastname: Shimada
authors.forename: Mikio
authors.initials: M
authors.lastname: Nishimura
authors.forename: Ikuko
authors.initials: I
authors.lastname: Hara-Nishimura
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000502:physiology* / Q000648:ultrastructure; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008854:Microscopy, Electron; D009154:Mutation; D018514:Plant Structures / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D030821:Plants, Genetically Modified; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D001617:beta-Glucosidase / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; C473372:PYK10 protein, Arabidopsis; D001617:beta-Glucosidase