Actin cytoskeleton in plants: from transport networks to signaling networks

Microsc Res Tech. 1999 Oct 15;47(2):135-54. doi: 10.1002/(SICI)1097-0029(19991015)47:2<135::AID-JEMT6>3.0.CO;2-1.

Abstract

The plant actin cytoskeleton is characterized by a high diversity in regard to gene families, isoforms, and degree of polymerization. In addition to the most abundant F-actin assemblies like filaments and their bundles, G-actin obviously assembles in the form of actin oligomers composed of a few actin molecules which can be extensively cross-linked into complex dynamic meshworks. The role of the actomyosin complex as a force generating system - based on principles operating as in muscle cells - is clearly established for long-range mass transport in large algal cells and specialized cell types of higher plants. Extended F-actin networks, mainly composed of F-actin bundles, are the structural basis for this cytoplasmic streaming of high velocities On the other hand, evidence is accumulating that delicate meshworks built of short F-actin oligomers are critical for events occurring at the plasma membrane, e.g., actin interventions into activities of ion channels and hormone carriers, signaling pathways based on phospholipids, and exo- and endocytotic processes. These unique F-actin arrays, constructed by polymerization-depolymerization processes propelled via synergistic actions of actin-binding proteins such as profilin and actin depolymerizing factor (ADF)/cofilin are supposed to be engaged in diverse aspects of plant morphogenesis. Finally, rapid rearrangements of F-actin meshworks interconnecting endocellular membranes turn out to be especially important for perception-signaling purposes of plant cells, e.g., in association with guard cell movements, mechano- and gravity-sensing, plant host-pathogen interactions, and wound-healing.

Publication types

  • Review

MeSH terms

  • Actins / analysis
  • Actins / physiology*
  • Cell Polarity
  • Cell Size
  • Chloroplasts / metabolism
  • Cytoskeleton / chemistry*
  • Eukaryota / cytology
  • Immunohistochemistry
  • Intercellular Junctions / chemistry
  • Microscopy, Electron
  • Myosins / physiology
  • Plants / ultrastructure*
  • Plastids / physiology
  • Signal Transduction*
  • Wound Healing / physiology

Substances

  • Actins
  • Myosins