Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis-2

Tion. Yellow broken lines indicate parental cell wall. Effect of BA treatment on MFs in cytokinetic BY-2 cells. BY-GF11 cells were treated with DMSO or 1 μM BA for 1 h. Representative images of a single optical section at the mid-plane (mid-plane) and maximum intensity projection (projection) are presented. Time-lapse images of FM4-64-labelled cell plate expansion in BA-treated cells. Time 0 min represents chromosomal separation. Yellow broken lines indicate parental cell wall. Effect of BA treatment on the duration between chromosomal separation and complete fusion of a cell plate and parental cell wall. Note that the duration times in BA-treated cells were longer than those in control cells, and were independent of cell size. The data were obtained from 12 independent experiments of each condition. Scale bars indicate 10 μm.<p><b>Copyright information:</b></p><p>Taken from "Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis"</p><p>http://www.biomedcentral.com/1471-2229/8/80</p><p>BMC Plant Biology 2008;8():80-80.</p><p>Published online 17 Jul 2008</p><p>PMCID:PMC2490694.</p><p></p

Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis-0

11 cell. Green and red indicate GFP-ABD2 and FM4-64 fluorescence, respectively. Asterisks indicate actin microfilament twin peaks that appeared at metaphase []. We defined 0 min as the end of metaphase in this figure. Scale bar indicates 25 μm.Changes in GFP-ABD2 and FM4-64 fluorescence intensities around the division plane. Intensities were time-sequentially measured along the division plane at a width of 9 μm, shown as the boxed region in (A). Data in (B) are mean values ± SE of four independent experiments. Kymographs obtained by drawing a line across a cell plate from metaphase to late telophase, as shown by the yellow arrow in (A). Yellow broken lines indicate changes in MF localization during cell plate development. One representative experiment of four independent experiments is shown.<p><b>Copyright information:</b></p><p>Taken from "Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis"</p><p>http://www.biomedcentral.com/1471-2229/8/80</p><p>BMC Plant Biology 2008;8():80-80.</p><p>Published online 17 Jul 2008</p><p>PMCID:PMC2490694.</p><p></p

Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis-5

Copic images presented in this figure were focused at the tangential surface of the cell plate. CP represents the cell plate. Interaction of endosomes with the edge of a cell plate. Magnified and time-sequential images of the boxed region in (C) are shown. To facilitate endosome visualization, images are presented in pseudo-color. Movement of an endosome (yellow arrowheads) towards the cell plate (0–4 sec) and merger with the edge (5 sec). Movement of endosomes stained with FM4-64 around a cell plate in control (C), BA-treated (D) and BDM-treated (E) cells. Images at 0, 15 and 30 sec are colored in red, green, and blue, respectively, and projected together. Scale bars indicate 10 μm.Tracking of endosomal movement in control (F), BA-treated (G) and BDM-treated (H) cells. Confocal sections were taken at 1-sec intervals for 30 sec, and the endosomes were tracked by ImageJ software (see Methods). Frequency histograms of endosome velocity over a 30 sec period. Data were obtained from 599 (I), 488 (J), 382 (K) endosomes from 10 control (I), 18 BA-treated (J), and 15 BDM-treated (K) cells, respectively. Dual observations of MFs (L) and moving endosomes (M and N). To facilitate endosome visualization, images are presented in pseudo-color as in (B). MF structures around the cell plate edge (L) and endosome movement (N, yellow arrowheads) were observed simultaneously. To facilitate visualization of the movement, maximum intensity projections of the time-sequential images are presented (M). Note the movement of an endosome towards the cell plate along the MFs. CP represents the cell plate. Scale bar indicates 5 μm.<p><b>Copyright information:</b></p><p>Taken from "Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis"</p><p>http://www.biomedcentral.com/1471-2229/8/80</p><p>BMC Plant Biology 2008;8():80-80.</p><p>Published online 17 Jul 2008</p><p>PMCID:PMC2490694.</p><p></p

Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis-6

Ntrol cell. ER accumulated around the edge of the expanding cell plate before completion of cytokinesis (yellow arrowheads). Projection image of ER at late telophase in a control cell. Time-lapse images of GFP-labeled ER and FM4-64-labeled cell plate in a BA-pretreated cell. Accumulation of ER in the phragmoplast was inhibited (yellow arrows) compared with the control cell shown in (A). Projection image of ER at late telophase in a BA-treated cell. Changes in GFP and FM4-64 fluorescence intensities around the division plane. Intensities were time-sequentially measured in the division plane at a width of 9 μm, as shown in the boxed region of (A) and (C). Data in (E) are mean values ± SEs of four independent experiments.<p><b>Copyright information:</b></p><p>Taken from "Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis"</p><p>http://www.biomedcentral.com/1471-2229/8/80</p><p>BMC Plant Biology 2008;8():80-80.</p><p>Published online 17 Jul 2008</p><p>PMCID:PMC2490694.</p><p></p

Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis-8

, respectively. Intensity profiles of GFP-ABD2 and FM4-64 along the line segment PQ in (A).Cross-sections of GFP-ABD2 (C) and FM4-64 (D) along the line segment PQ in (A). Merged images of (C) and (D). Single optical section of a BY-GF11 cell at late-telophase. Green and red indicate GFP-ABD2 and FM4-64 fluorescence, respectively. Intensity profiles of GFP-ABD2 and FM4-64 along the line segment RS in (F). and Cross sections of GFP-ABD2 (H) and FM4-64 (I) along the line segment RS in (F). Merged images of (H) and (I). Optical sections, which were used for reconstruction of a cross-section, were taken at 0.5 μm intervals. Scale bars indicate 10 μm.<p><b>Copyright information:</b></p><p>Taken from "Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis"</p><p>http://www.biomedcentral.com/1471-2229/8/80</p><p>BMC Plant Biology 2008;8():80-80.</p><p>Published online 17 Jul 2008</p><p>PMCID:PMC2490694.</p><p></p

Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis-7

11 cell. Green and red indicate GFP-ABD2 and FM4-64 fluorescence, respectively. Asterisks indicate actin microfilament twin peaks that appeared at metaphase []. We defined 0 min as the end of metaphase in this figure. Scale bar indicates 25 μm.Changes in GFP-ABD2 and FM4-64 fluorescence intensities around the division plane. Intensities were time-sequentially measured along the division plane at a width of 9 μm, shown as the boxed region in (A). Data in (B) are mean values ± SE of four independent experiments. Kymographs obtained by drawing a line across a cell plate from metaphase to late telophase, as shown by the yellow arrow in (A). Yellow broken lines indicate changes in MF localization during cell plate development. One representative experiment of four independent experiments is shown.<p><b>Copyright information:</b></p><p>Taken from "Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis"</p><p>http://www.biomedcentral.com/1471-2229/8/80</p><p>BMC Plant Biology 2008;8():80-80.</p><p>Published online 17 Jul 2008</p><p>PMCID:PMC2490694.</p><p></p

Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis-3

Ircle) cells. Time 0 min represents the initiation of cell plate formation. Values are arithmetic means ± SE from 12 independent experiments. The continuous and broken lines represent the regression curves for cell plate diameter of control and BA-treated cells, respectively, calculated from model equation 1 (A) or 2 (B). In model equation 1, the expansion rate is constant (A). In model equation 2, the expanding rate undergoes time-dependent changes (B). When the control data was applied to model equation 2, became underspecified and was consequently assumed to be invariant at 1.81. Comparison of -values in chi-square goodness of fit tests. The -value indicates the probability that an observed difference between the measured and predicted values by model equations 1 or 2 occurred by chance alone. If the -value is less than the significant level at 0.05, we cannot accept that there are no differences between the measured and predicted values. Note that the data fit model equation 2 (B) much better than model equation 1 (A). Simulation of changes in the effects of BA treatment on expansion rate calculated at 1 min intervals. The values are arithmetic means ± SE from 12 independent calculation results of . The 12 parameter sets and were the same as calculated in (B). Significance was determined using Student's t-test. -value *< 0.05. **<p><b>Copyright information:</b></p><p>Taken from "Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis"</p><p>http://www.biomedcentral.com/1471-2229/8/80</p><p>BMC Plant Biology 2008;8():80-80.</p><p>Published online 17 Jul 2008</p><p>PMCID:PMC2490694.</p><p></p

Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis-1

, respectively. Intensity profiles of GFP-ABD2 and FM4-64 along the line segment PQ in (A).Cross-sections of GFP-ABD2 (C) and FM4-64 (D) along the line segment PQ in (A). Merged images of (C) and (D). Single optical section of a BY-GF11 cell at late-telophase. Green and red indicate GFP-ABD2 and FM4-64 fluorescence, respectively. Intensity profiles of GFP-ABD2 and FM4-64 along the line segment RS in (F). and Cross sections of GFP-ABD2 (H) and FM4-64 (I) along the line segment RS in (F). Merged images of (H) and (I). Optical sections, which were used for reconstruction of a cross-section, were taken at 0.5 μm intervals. Scale bars indicate 10 μm.<p><b>Copyright information:</b></p><p>Taken from "Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis"</p><p>http://www.biomedcentral.com/1471-2229/8/80</p><p>BMC Plant Biology 2008;8():80-80.</p><p>Published online 17 Jul 2008</p><p>PMCID:PMC2490694.</p><p></p

A Theoretical Model of Jigsaw-Puzzle Pattern Formation by Plant Leaf Epidermal Cells

<div><p>Plant leaf epidermal cells exhibit a jigsaw puzzle–like pattern that is generated by interdigitation of the cell wall during leaf development. The contribution of two ROP GTPases, ROP2 and ROP6, to the cytoskeletal dynamics that regulate epidermal cell wall interdigitation has already been examined; however, how interactions between these molecules result in pattern formation remains to be elucidated. Here, we propose a simple interface equation model that incorporates both the cell wall remodeling activity of ROP GTPases and the diffusible signaling molecules by which they are regulated. This model successfully reproduces pattern formation observed <i>in vivo</i>, and explains the counterintuitive experimental results of decreased cellulose production and increased thickness. Our model also reproduces the dynamics of three-way cell wall junctions. Therefore, this model provides a possible mechanism for cell wall interdigitation formation <i>in vivo</i>.</p></div

A three-way junction became a forced cytoplasmic protrusion and may affect downstream molecular pathways.

<p>(a) Maximum intensity projection of GFP-tubulin in cotyledon leaf epidermal cells. White arrows and red arrowheads indicate pavement interdigitation and a three-way junction, respectively. Scale bar = 10 μm. (b, c) A representative circle with a radius of 5 μm centered at an interdigitation point (b) and a three-way junction point. (c) Red points indicate GFP-tubulin intensity peaks detected as anticlinal cortical microtubules. (d) Density of anticlinal cortical microtubules in interdigitation and three-way junction areas. Data are mean values from 134 and 161 independent regions, respectively. A statistically significant difference is observed using the Mann–Whitney U-test (p = 4.366e−8). (e) Relative strength of ROP2 (cyan) and ROP6 (magenta) activities in a numerical simulation. The three-way junction region functioned as a forced cytoplasmic protrusion at which the ROP2 pathway was expected to be dominant. ROP2 activity was monitored by the distribution of cortical microtubules.</p