Dynamic apico-basal enrichment of the F-actin during cytokinesis in Arabidopsis cells embedded in their tissues

Abstract

Cell division is a tightly regulated mechanism, notably in tissues where malfunctions can lead to tumour formation or developmental defects. This is particularly true in land plants, where cells cannot relocate and therefore cytokinesis determines tissue topology. In plants, cell division is executed in radically different manners than in animals, with the appearance of new structures and the disappearance of ancestral mechanisms. Whilst F-actin and microtubules closely co-exist, recent studies mainly focused on the involvement of microtubules in this key process. Here, we used a root tracking system to image the spatio-temporal dynamics of both F-actin reporters and cell division markers in dividing cells embedded in their tissues. In addition to the F-actin accumulation at the phragmoplast, we observed and quantified a dynamic apico-basal enrichment of F-actin from the prophase/metaphase transition until the end of the cytokinesis.

Tools for studying the cytoskeleton during plant cell division

“…It does not inhibit the formation of the PPB in BY-2 cells, but inhibits the narrowing process that defines the precise CDZ [17]. This result is consistent with the absence of AFs in the PPB in Arabidopsis roots [18]. In Physcomitrium patens, in which the division site is defined by active spindle-positioning mechanisms, latrunculin-A abolishes basal spindle motility [19].…”

Stabilization of F-Actin Cytoskeleton by Paclitaxel Improves the Blastocyst Developmental Competence through P38 MAPK Activity in Porcine Embryos

“…Interestingly, the functional effects of 10 nM paclitaxel as a microtubule stabilization agent improved the expression of F-actin at the joint sites of cleaving blastomeres. Enrichment of F-actin enhances the stability of spindle formation during cytokinesis and plays a vital role in chromosome segregation during the cell cycle [ 42 ]. The results shown in Figure 3 K confirmed that 10 nM paclitaxel treatment maintained spindle microtubule bundle length at the blastocyst stage.…”

Plant cell division from the perspective of polarity

“…MFs are initially localized at the PPB and later excluded from the Actin depleted zone (ADZ), which overlaps with the CDZ; nonetheless, as MFs require MTs for PPB localization, but not vice versa, these dynamic actin rearrangements have been assigned secondary importance for division plane determination (Palevitz, 1987;Liu and Palevitz, 1992;Rasmussen et al, 2013;Smertenko et al, 2017). In another polarized actin rearrangement coinciding with, and potentially regulating CDZ and division plane establishment, MFs are enriched at the apical and basal poles of anticlinally dividing root meristem cells (Collings et al, 2005;Lebecq et al, 2022). Additionally, numerous observations of division orientation defects resulting from interference with MFs in different tissues (i.a.…”