Distribution and characterization of peroxisomes in Arabidopsis by visualization with GFP: dynamic morphology and actin-dependent movement.
Peroxisomes were visualized in living cells of various tissues in transgenic Arabidopsis by green fluorescent protein (GFP) through the addition of the peroxisomal targeting signal 1 (PTS1) or PTS2. The observation using confocal laser scanning microscopy revealed that the GFP fluorescence signals were detected as spherical spots in all cells of two kinds of transgenic plants. Immunoelectron microscopic analysis using antibodies against the peroxisomal marker protein, catalase, showed the presence of GFP in peroxisomes, confirming that GFP was correctly transported into peroxisomes by PTS1 or PTS2 pathways. It has been also revealed that peroxisomes are motile organelles whose movement might be caused by cytoplasmic flow. The movement of peroxisomes was more prominent in root cells than that in leaves, and divided into two categories: a relatively slow, random, vibrational movement and a rapid movement. Treatment with anti-actin and anti-tubulin drugs revealed that actin filaments involve in the rapid movement of peroxisomes. Moreover, abnormal large peroxisomes are present as clusters at the onset of germination, and these clusters disappear in a few days. Interestingly, tubular peroxisomes were also observed in the hypocotyl. These findings indicate that the shape, size, number and movement of peroxisomes in living cells are dynamic and changeable rather than uniform.
Mano
Shoji
S
Department of Cell Biology, National Institute for Basic Biology, Okazaki, 444-8585, Japan.
Nakamori
Chihiro
C
Hayashi
Makoto
M
Kato
Akira
A
Kondo
Maki
M
Nishimura
Mikio
M
D008841:Actin Cytoskeleton / Q000378:metabolism; D000199:Actins / Q000037:antagonists & inhibitors; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D002478:Cells, Cultured; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D018613:Microscopy, Confocal; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D000074437:Peroxisomal Targeting Signal 2 Receptor; D000074435:Peroxisome-Targeting Signal 1 Receptor; D020675:Peroxisomes / Q000378:metabolism* / Q000648:ultrastructure; D018514:Plant Structures / Q000378:metabolism; D030821:Plants, Genetically Modified; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000166:cytology; D050257:Tubulin Modulators
D000199:Actins; D008164:Luminescent Proteins; D000074437:Peroxisomal Targeting Signal 2 Receptor; D000074435:Peroxisome-Targeting Signal 1 Receptor; D018160:Receptors, Cytoplasmic and Nuclear; D011993:Recombinant Fusion Proteins; D050257:Tubulin Modulators; D049452:Green Fluorescent Proteins