Organization of cortical microfilaments in dividing root cells

Abstract

In order to assess the possible role of microfilaments (Mfs) in events preceding plant cell division, actin was localized in root cells of Allium cepa and Tradescantia vivginiana by immunofluorescence microscopy. The distribution of Mfs was compared to that of microtubules (Mts) by means of dual localizations employing both antiactin and antitubulin. Cycling interphase cells contain Mfs that extend into all regions of the cytoplasm in random fashion. Prior to the rearrangement of the cortical Mt array into the initial broad preprophase band (PPB), the number of Mfs in the cytoplasm decreases, while a new population appears in the cortex. The cortical Mfs, which usually occupy the entire cell surface, are aligned parallel to the cortical Mts. When the initial PPB appears, these Mfs still cover the cortex or are arranged as a broad band encompassing the PPB. As the PPB narrows, the Mfs are also confined to an increasingly restricted zone usually wider than the PPB. When the PPB reaches its narrowest, densest configuration, aligned Mfs are excluded from the band proper, while others appear in flanking regions of the cortex. From prometaphase through anaphase, cortical Mfs are largely restricted to the ends of the cell overlying the spindle poles; they also tend to become more randomly oriented. Little or no actin is present in the spindle. During telophase, the two zones of aligned cortical Mfs over the ends of the cell gradually disappear and are replaced by new interphase networks. These changes provide additional data on the possible control of PPB organization by actin, and in addition indicate that the cortex may be the origin of the actin that aggregates at the spindle poles during cytochalasin treatment.1992 Wiley-Liss, Inc.

Effect of n-butanol and cold pretreatment on the cytoskeleton and the ultrastructure of maize microspores when cultured in vitro

“…Although literature data suggests that different arrays of microtubules are main factors involved in the establishment of division plane and cell plate (Rasmussen et al 2013), it is proven that depolymerization of actin filaments during cell division alters division symmetry in vegetative cells (Liu and Palevitz 1992;Eleftheriou and Palevitz 1992) and even in microspores, inducing embryogenesis (Gervais et al 2000). To sum up literature data, it can be said that cooperation of microtubule and actin arrays during thelophase and cytokinesis is necessary for the formation of normal cell walls.…”

The maize actin‐depolymerizing factor, ZmADF3, redistributes to the growing tip of elongating root hairs and can be induced to translocate into the nucleus with actin

“…The root tips, including the apical zone and the zone of root hair initiation, of 3-4 day maize seedlings were fixed for 90 min in 3% formaldehyde, 0.05% glutaraldehyde, 1% glycerol, 2% dimethyl sulphoxide (DMSO) in PME buffer (50 mM Pipes, pH 6.8, 2 mM MgCI 2, 5 mM EGTA) (Liu and Palevitz, 1992). After rinsing in PME buffer the material was digested for 60 rain at 27°C in a solution of 1% cellulase Onozuka RS (Yakult Pharmaceutical Co., Takarazuka,…”

Deletion of nudC, a nuclear migration gene of Aspergillus nidulans, causes morphological and cell wall abnormalities and is lethal.

“…Slides were photographed by using a Zeiss Axioplan microscope with a 10OX Neofluar objective and Tmax 400 (Kodak) or Super HGV 400 (Fuji) films. DAPI and actin staining were as previously described (Liu and Palevitz, 1992), using 0.5 ,Lg/ml DAPI. Chitin was stained with the same procedure as for DAPI staining except that 1 mg/ml Calcofluor White M2R (Sigma, St. Louis, MO) was used in the mounting buffer instead of DAPI.…”