Statoliths and microfilaments in plant cells.
Microfilaments have been demonstrated in rhizoids of Chara fragilis Desvaux by labelling of actin with rhodamine-conjugated phalloidin. Each rhizoid contains thick microfilament-bundles arranged longitudinally in the basal region. In the subapical and apical regions, much thinner bundles exist which contact the statoliths and encircle them in the form of a dense envelope. In root statocytes from Lepidium sativum L. the presence of an actin network is indicated by the fact that application of cytochalasin B (25 micrograms ml-1 for 4 h) results in an approximately threefold increase in the rate of statolith (amyloplast) sedimentation relative to controls. It is concluded that in gravity-perceiving plant cells statoliths may trigger the transduction mechanism via actin filaments.
Sievers
A
A
Botanisches Institut, Universitat Bonn, Federal Republic of Germany.
Kruse
S
S
Kuo-Huang
L L
LL
Wendt
M
M
D008841:Actin Cytoskeleton / Q000187:drug effects / Q000502:physiology*; D000199:Actins / Q000502:physiology; D019607:Brassicaceae / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure*; D000460:Chlorophyta / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure*; D003571:Cytochalasin B / Q000494:pharmacology; D004721:Endoplasmic Reticulum / Q000502:physiology; D018522:Gravitropism / Q000502:physiology; D018466:Gravity Sensing / Q000187:drug effects / Q000502:physiology*; D018517:Plant Roots / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D018087:Plastids / Q000187:drug effects / Q000502:physiology*
D000199:Actins; D003571:Cytochalasin B