The authors thank Dr. Soucy Patricia and Betty Nunn at the University of Louisville for assistance with the confocal microscope. This work was funded by the National Science Foundation (1456884 to M.P.R.) and by a National Science Foundation Cooperative Agreement (1849213 to M.P.R.).

NOTE: See the Table of Materials for the list of materials and equipment and Table 1 for the list of solutions to be used in this protocol.
1. Preparation of plants for glass bottom dishes
<ol>
	<li>Grow the moss protonemal tissue in BCDAT agar medium in a 13 cm Petri dish under constant white light (~50 &#181;mol m-2s-1) for 7 days at 25 &#176;C in the growth chamber.</li>
	<li>Filter-sterilize the calcofluor white and...

<ol>
	<li>Anderson, C. T., Kieber, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+construction,+perception,+and+remodeling+of+plant+cell+walls.">Dynamic construction, perception, and remodeling of plant cell walls.</a> Annual Review of Plant Biology. 71, 39-69 (2020).</li><li>Vaahtera, L., Schulz, J., Hamann, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+wall+integrity+maintenance+during+plant+development+and+interaction+with+the+environment.">Cell wall integrity maintenance during plant development and interaction with the environment.</a> Naure Plants. 5 (9), 924-932 (2019).</li><li>Bao, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+cellular+function+of+ROP+GTPase+prenylation+important+for+multicellularity+in+the+moss+Physcomitrium+patens.">The cellular function of ROP GTPase prenylation important for multicellularity in the moss Physcomitrium patens.</a> Development. 149 (12), (2022).</li><li>Colin, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+the+living+plant+cell:+From+probes+to+quantification.">Imaging the living plant cell: From probes to quantification.</a> The Plant Cell. 34 (1), 247-272 (2022).</li><li>Fang, Y., Spector, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Live+cell+imaging+of+plants.">Live cell imaging of plants.</a> Cold Spring Harbor Protocols. 2010 (2), (2010).</li><li>Goh, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+live-cell+imaging+approaches+to+study+lateral+root+formation+in+Arabidopsis+thaliana.">Long-term live-cell imaging approaches to study lateral root formation in Arabidopsis thaliana.</a> Microscopy. 68 (1), 4-12 (2019).</li><li>Hamant, O., Das, P., Burian, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Time-lapse+imaging+of+developing+shoot+meristems+using+a+confocal+laser+scanning+microscope.">Time-lapse imaging of developing shoot meristems using a confocal laser scanning microscope.</a> Methods in Molecular Biology. 1992, 257-268 (2019).</li><li>Rigal, A., Doyle, S. M., Robert, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Live+cell+imaging+of+FM4-64,+a+tool+for+tracing+the+endocytic+pathways+in+Arabidopsis+root+cells.">Live cell imaging of FM4-64, a tool for tracing the endocytic pathways in Arabidopsis root cells.</a> Methods in Molecular Biology. 1242, 93-103 (2015).</li><li>Yagi, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advances+in+synthetic+fluorescent+probe+labeling+for+live-cell+imaging+in+plants.">Advances in synthetic fluorescent probe labeling for live-cell imaging in plants.</a> Plant &amp; Cell Physiology. 62 (8), 1259-1268 (2021).</li><li>Whitewoods, C. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CLAVATA+was+a+genetic+novelty+for+the+morphological+innovation+of+3D+growth+in+land+plants.">CLAVATA was a genetic novelty for the morphological innovation of 3D growth in land plants.</a> Current Biology. 28 (15), 2365-2376 (2018).</li><li>Bao, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+PSTAIRE-type+cyclin-dependent+kinase+controls+light+responses+in+land+plants.">A PSTAIRE-type cyclin-dependent kinase controls light responses in land plants.</a> Science Advances. 8 (4), 2116 (2022).</li></ol>

The authors declare no competing or financial interests.

Time-lapse 3-D reconstruction, or 4-D imaging, is a powerful tool for observing the dynamics of cellular morphology during developmental processes. In this protocol, by mixing the calcofluor white in the medium, the dynamics of 3-D cellular morphology can be observed in the moss P. patens. Using this method, we observed that the surface of cell walls in ggb mutants are torn apart during development3. Moreover, the reduced thickening of cell walls is correlated with the cell expan...

Plant cell walls undergo dynamic changes during cell expansion and development1,2,3. Maintaining cell wall integrity is critical for plant cell adhesion during growth and development, as well as for the response to environmental signals. Although visualizing cell wall dynamics of living cells over a long period of time is critical to understanding how cell adhesion is maintained during development and adaptation to environmental changes, current methods for directly observing cell wall dynamics are still challenging.
Time-lapse imaging of cellular changes can provide informative developmental dynamics of an organism using a high-resolution fluorescence microscope4,5,6,7. While time-lapse 3-D imaging has a great deal of potential for studying dynamic changes of cell shape during growth and development, the technique normally requires transformation of a fluorescent protein4,5,6,7. However, for most systems, genetic transformations are either time-consuming or technically challenging. As an alternative, fluorescent dyes that attach to cellular components have long been available. The fluorescent dyes can emit fluorescent light after irradiation with light of a certain wavelength. Common examples are Edu, DAPI, PI, FM4-64, and calcofluor white8,9,10. One major drawback, however, is that these dyes can typically only be used in fixed tissue or for short experiments, in part due to the harm they cause to the cell8,9,10.
With the protocol presented here, calcofluor signals are stable when calcofluor white is mixed within the medium during time-lapse experiments in the moss P. patens. Using this method, the detachment of cells in ggb mutants using 3-D time-lapse imaging was observed over a 3 day period3 (Figure 1). This method can be applied to many other systems that contain cell walls and that can be stained by calcofluor.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>3-mm-thick red plastic light filter</td>
			<td>&#160;Mitsubishi</td>
			<td>&#160;no.102</td>
			<td></td>
		</tr>
		<tr>
			<td>27 mm diameter glass base dish&#160;</td>
			<td>Iwaki</td>
			<td>3930-035</td>
			<td></td>
		</tr>
		<tr>
			<td>Agar</td>
			<td>&#160;Sigma</td>
			<td>A6924</td>
			<td></td>
		</tr>
		<tr>
			<td>Calcofluor white&#160;</td>
			<td>&#160;Sigma</td>
			<td>18909-100ML-F</td>
			<td>Calcofluor White M2R, 1 g/L and Evans blue, 0.5 g/L</td>
		</tr>
		<tr>
			<td>Confocal microscope&#160;</td>
			<td>Nikon&#160;</td>
			<td>A1</td>
			<td>
			NIS element software; .nd2 file in NIS-elements Viewer, download from https://www.microscope.healthcare.nikon. 
			com/en_AOM/products/software/nis-elements/viewer
			</td>
		</tr>
		<tr>
			<td>Fluorescence microscope&#160;</td>
			<td>Nikon&#160;</td>
			<td>TE200&#160;</td>
			<td>Equipped with a DS-U3 camera;</td>
		</tr>
		<tr>
			<td>Gellan gum&#160;</td>
			<td>Nacali Tesque</td>
			<td>12389-96</td>
			<td></td>
		</tr>
		<tr>
			<td>Plant Growth Chambers</td>
			<td>SANYO&#160;</td>
			<td>Sanyo MLR-350H</td>
			<td></td>
		</tr>
		<tr>
			<td>Sterilized syringe 0.22 &#956;m filter</td>
			<td>Millipore</td>
			<td>SLGV033RS</td>
			<td></td>
		</tr>
	</tbody>
</table>

3-d time-lapse imaging of cell wall dynamics using calcofluor in the moss physcomitrium patens

Time-lapse imaging with fluorescence microscopy allows observation of the dynamic changes of growth and development at cellular and subcellular levels. In general, for observations over a long period, the technique requires transformation of a fluorescent protein; however, for most systems, genetic transformation is either time-consuming or technically unavailable. This manuscript presents a protocol for 3-D time-lapse imaging of cell wall dynamics over a 3 day period using calcofluor dye (which stains cellulose in the plant cell wall), developed in the moss Physcomitrium patens. The calcofluor dye signal from the cell wall is stable and can last for 1 week without obvious decay. Using this method, it has been shown that the detachment of cells in ggb mutants (in which the protein geranylgeranyltransferase-I beta subunit is knocked out) is caused by unregulated cell expansion and cell wall integrity defects. Moreover, the patterns of calcofluor staining change over time; less intensely stained regions correlate with the future cell expansion/branching sites in the wild type. This method can be applied to many other systems that contain cell walls and that can be stained by calcofluor.

This method allows the observation of cell wall dynamics during development in wild type and ggb mutants (Figure 1). The results showed that regions with less thickening of the cell wall correlate with the cell expansion/branching sites, allowing for the prediction of expansion/branching sites in the wild type (Figure 1A). The surface of the cell walls in ggb mutants was torn apart during development due to uncontrolled cell expansion<sup class...

Watch this Scientific Journal Video about 3-D Time-Lapse Imaging of Cell Wall Dynamics Using Calcofluor in the Moss Physcomitrium patens at JoVE.com

3-D Time-Lapse Imaging of Cell Wall Dynamics Using Calcofluor in the Moss Physcomitrium patens

This manuscript presents a detailed protocol to image the 3-D cell wall dynamics of living moss tissue, allowing the visualization of the detachment of cell walls in ggb mutants and thickening cell wall patterns in the wild type during development over a long period.

3-D Time-Lapse Imaging of Cell Wall Dynamics Using Calcofluor in the Moss Physcomitrium patens

Time-lapse imaging with fluorescence microscopy allows observation of the dynamic changes of growth and development at cellular and subcellular levels. In ...

Time-lapse imaging with fluorescence microscopy allows observation of the dynamic changes of growth and development at cellular and subcellular levels. This simple protocol for 3D time-lapse imaging can directly study cell wall dynamics over a long period. This protocol uses calcofluor dye to mark the dynamics of cell wall thickness, and therefore does not require a transformation of a fluorescent protein.The calcofluor signals are stable and can last for more than a week. This method may be applied to many other systems with simple structures containing cell walls and can be stained by calcofluor such as in flowering plants. In this protocol, the calcofluor signals are stable when this dye is mixed within the medium during the whole process of time-lapse imaging.To begin, disperse the seven day old moss tissue into a 1.5 milliliter micro tube containing 20 microliters of sterilized water. For the wild type use forceps to separate the protonemata. For the ggb mutant, separate the protonemata using AP-1000 pipette.Add 10 microliters of the sterilized calcofluor-white into the microtube and leave the tube upright in the hood for two minutes for staining. Immediately after staining, mix the plants with 200 microliters of cooled BCDATG containing BCDAT medium by pipetting five times with a P1000 pipette and transfer the mixture into a 27 millimeter glass base dish. Ensure that the 200 microliters of BCDATG with samples is evenly distributed on the surface of the 27 millimeter glass bottom dish to produce a thin layer of film so that the samples are within the objective working distance during imaging.After solidifying for two minutes at room temperature, cover the thin layer with three milliliters of cooled BCDATG and let it set for 10 minutes to solidify again. On the bottom of the dish draw nine lines each in parallel and perpendicular directions and mark the rows with characters from A to H, and the columns with numbers from one to eight. Use upper, lower, right, middle, and left to mark the positions within each square.For example, if a plant is in a square in the second row, in the sixth column and is positioned in the upper left part of the square, then this plant is given the name of b6 upper left. Place the glass bottom dish under white light for one to two days before being subjected to time-lapse imaging every day, for up to three days. To reconstruct the 3D images open the ND2 file and click volume.Reconstruct the cell wall at day zero, day one, day three, and day four. After taking each image, put the glass based dish back into the grow chamber. Dynamic changes in cross walls were shown by calcofluor-white staining in wild type, and ggb mutants.For ggb mutants, white dashed lines below each image indicate the broken surface cell wall in the expanding cells and orange lines indicate the cells beneath the cell wall surface in ggb. The differences in calcofluor-white signal can be detected on the surface positions of the cells and less densely stained regions indicated cell expansion in ggb mutants or newly branching sites in the wild type. For wild type pre culture, the plants in weak red light from the above for five days is required to induce the phototropic responses of protonemata so that the plants can be attached to the bottom of dishes and the plants can be emerged within the objective upworking distance during imaging because calcofluor-white can be used with other dye such as microsphere.Additional information about the cell expansion can also be studied. Dynamics of plant cell wall is critical for efficient doing growth and development as well as for response to environmental signal. This protocol allows for direct of the division of changes in cell wall signals and integrating.

3-d-time-lapse-imaging-cell-wall-dynamics-using-calcofluor-moss

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JoVE Journal

Developmental Biology

1.3K visualizações.  University of Louisville. A imagem de lapso de tempo com microscopia de fluorescência permite a observação das mudanças dinâmicas de crescimento e desenvolvimento nos níveis celular e subcelular. Este protocolo simples para imagens de lapso de tempo 3D pode estudar diretamente a dinâmica da parede celular durante um longo período. Este protocolo utiliza corante calcofluor para marcar a dinâmica da espessura da parede celular e, portanto, não requer uma transformação de uma proteína fluorescente.Os ...