Protoplasma

, Volume 185, Issue 3, pp 152–165

F-actin redistributions at the division site in livingTradescantia stomatal complexes as revealed by microinjection of rhodamine-phalloidin

Authors

  • A. L. Cleary
    • Plant Cell Biology Group, Research School of Biological SciencesThe Australian National University
Article

DOI: 10.1007/BF01272855

Cite this article as:
Cleary, A.L. Protoplasma (1995) 185: 152. doi:10.1007/BF01272855

Summary

Microinjection of rhodamine-phalloidin into living cells of isolatedTradescantia leaf epidermis and visualisation by confocal microscopy has extended previous results on the distribution of actin in mitotic cells of higher plants and revealed new aspects of actin arrays in stomatal cells and their initials. Divisions in the stomatal guard mother cells and unspecialised epidermal cells are symmetrical. Asymmetrical divisions occur in guard mother precursor cells and subsidiary mother cells. Each asymmetrical division is preceded by migration of the nucleus and the subsequent accumulation of thick bundles of anticlinally oriented actin filaments localised to the area of the anticlinal wall closest to the polarised nucleus. During prophase, in all cell types, a subset of cortical actin filaments coaligns to form a band, which, like the preprophase band of microtubules, accurately delineates the site of insertion of the future cell wall. Following the breakdown of the nuclear envelope, F-actin in these bands disassembles but persists elsewhere in the cell cortex. Thus, cortical F-actin marks the division site throughout mitosis, firstly as an appropriately positioned band and then by its localised depletion from the same region of the cell cortex. This sequence has been detected in all classes of division inTradescantia leaf epidermis, irrespective of whether the division is asymmetrical or symmetrical, or whether the cell is vacuolate or densely cytoplasmic. Taken together with earlier observations on stamen hair cells and root tip cells it may therefore be a general cytoskeletal feature of division in cells of higher plants.

Keywords

Actin-depleted zoneActin bandDivision sitePlant actinSubsidiary mother cellTradescantia

Abbreviations

GMC

guard mother cell

MT

microtubule

PPB

preprophase band

Rh

rhodamine

SMC

subsidiary mother cell

Copyright information

© Springer-Verlag 1995