title: Visualization of peroxisomes in living plant cells reveals acto-myosin-dependent cytoplasmic streaming and peroxisome budding.
abstract: Here we examine peroxisomes in living plant cells using transgenic Arabidopsis thaliana plants expressing the green fluorescent protein (GFP) fused to the peroxisome targeting signal 1 (PTS1). Using time-lapse laser scanning confocal microscopy we find that plant peroxisomes exhibit fast directional movement with peak velocities approaching 10 microm s(-1). Unlike mammalian peroxisomes which move on microtubules, plant peroxisome movement is dependent on actin microfilaments and myosin motors, since it is blocked by treatment with latrunculin B and butanedione monoxime, respectively. In contrast, microtubule-disrupting drugs have no effect on peroxisome streaming. Peroxisomes were further shown to associate with the actin cytoskeleton by the simultaneous visualization of actin filaments and peroxisomes in living cells using GFP-talin and GFP-PTS1 fusion proteins, respectively. In addition, peroxisome budding was observed, suggesting a possible mechanism of plant peroxisome proliferation. The strong signal associated with the GFP-PTS1 marker also allowed us to survey cytoplasmic streaming in different cell types. Peroxisome movement is most intense in elongated cells and those involved in long distance transport, suggesting that higher plants use cytoplasmic streaming to help transport vesicles and organelles over long distances.
authors.affiliation: Laboratory of Plant Molecular biology, The Rockefeller University, 1230 York Avenue, New York, NY 10021-6399, USA. jeddg@rockvax.rockefeller.edu
authors.forename: Gregory
authors.initials: G
authors.lastname: Jedd
authors.forename: Nam-Hai
authors.initials: NH
authors.lastname: Chua
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D017360:Arabidopsis / Q000187:drug effects / Q000502:physiology*; D001549:Benzamides / Q000494:pharmacology; D001692:Biological Transport / Q000502:physiology; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D003595:Cytoplasmic Streaming / Q000187:drug effects / Q000502:physiology*; D003931:Diacetyl / Q000031:analogs & derivatives* / Q000494:pharmacology; D049452:Green Fluorescent Proteins; D018546:Hypocotyl / Q000187:drug effects / Q000502:physiology; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D018613:Microscopy, Confocal; D016253:Microscopy, Immunoelectron; D008870:Microtubules / Q000187:drug effects / Q000502:physiology; D009218:Myosins / Q000378:metabolism*; D015739:Nocodazole / Q000494:pharmacology; D000074435:Peroxisome-Targeting Signal 1 Receptor; D020675:Peroxisomes / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D018517:Plant Roots / Q000187:drug effects / Q000502:physiology; D030821:Plants, Genetically Modified; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016608:Talin / Q000235:genetics / Q000378:metabolism; D013844:Thiazoles / Q000494:pharmacology; D053778:Thiazolidines
chemical_list: D000199:Actins; D001549:Benzamides; D019086:Bridged Bicyclo Compounds, Heterocyclic; D008164:Luminescent Proteins; D000074435:Peroxisome-Targeting Signal 1 Receptor; D018160:Receptors, Cytoplasmic and Nuclear; D011993:Recombinant Fusion Proteins; D016608:Talin; D013844:Thiazoles; D053778:Thiazolidines; D049452:Green Fluorescent Proteins; C004717:diacetylmonoxime; C001059:pronamide; D009218:Myosins; D003931:Diacetyl; C037068:latrunculin B; D015739:Nocodazole