We set up this protocol in the single-cell multi-omics facility of the School of Agriculture and Biology, Shanghai Jiao Tong University, and were supported by the National Natural Science Foundation of China (Grant No. 32070608), the Shanghai Pujiang Program (Grant No. 20PJ1405800), and Shanghai Jiao Tong University (Grant Nos. Agri-X20200202, 2019TPB05).

The following protocol has been optimized for A. thaliana wild-type (WT) seeds with no fluorescence and fluorescent marker lines for the following root cell types: xylem-pole pericycle cells (J0121), lateral root initial cells, lateral root cap cells (J3411), endodermis and cortex&#160;cells&#160;(J0571) (Figure 1A). All the marker lines were obtained from a commercial source (see Table of Materials), except for the lateral root initiation cell marker line, which wa...

<ol>
	<li>Zhang, T. -. Q., Chen, Y., Liu, Y., Lin, W. -. H., Wang, J. -. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-cell+transcriptome+atlas+and+chromatin+accessibility+landscape+reveal+differentiation+trajectories+in+the+rice+root.">Single-cell transcriptome atlas and chromatin accessibility landscape reveal differentiation trajectories in the rice root.</a> Nature Communications. 12 (1), 2053 (2021).</li><li>Denyer, T., 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=Spatiotemporal+developmental+trajectories+in+the+Arabidopsis+root+revealed+using+high-throughput+single-cell+RNA+sequencing.">Spatiotemporal developmental trajectories in the Arabidopsis root revealed using high-throughput single-cell RNA sequencing.</a> Developmental Cell. 48 (6), 840-852 (2019).</li><li>Liu, Q., 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=Transcriptional+landscape+of+rice+roots+at+the+single-cell+resolution.">Transcriptional landscape of rice roots at the single-cell resolution.</a> Molecular Plant. 14 (3), 384-394 (2021).</li><li>Liu, Z., 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=Global+dynamic+molecular+profiling+of+stomatal+lineage+cell+development+by+single-cell+RNA+sequencing.">Global dynamic molecular profiling of stomatal lineage cell development by single-cell RNA sequencing.</a> Molecular Plant. 13 (8), 1178-1193 (2020).</li><li>Shahan, R., 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+single-cell+Arabidopsis+root+atlas+reveals+developmental+trajectories+in+wild-type+and+cell+identity+mutants.">A single-cell Arabidopsis root atlas reveals developmental trajectories in wild-type and cell identity mutants.</a> Developmental Cell. 57 (4), 543-560 (2022).</li><li>Wendrich, J. 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C., 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=G&amp;T-seq:+Parallel+sequencing+of+single-cell+genomes+and+transcriptomes.">G&amp;T-seq: Parallel sequencing of single-cell genomes and transcriptomes.</a> Nature Methods. 12 (6), 519-522 (2015).</li><li>Angermueller, C., 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=Parallel+single-cell+sequencing+links+transcriptional+and+epigenetic+heterogeneity.">Parallel single-cell sequencing links transcriptional and epigenetic heterogeneity.</a> Nature Methods. 13 (3), 229-232 (2016).</li><li>De Rybel, B., 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+novel+aux/IAA28+signaling+cascade+activates+GATA23-dependent+specification+of+lateral+root+founder+cell+identity.">A novel aux/IAA28 signaling cascade activates GATA23-dependent specification of lateral root founder cell identity.</a> Current Biology. 20 (19), 1697-1706 (2010).</li><li>Duncombe, S. G., Barnes, W. J., Anderson, C. T. <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+delivery+and+behavior+of+cellulose+synthases+in+Arabidopsis+thaliana+using+confocal+microscopy.">Imaging the delivery and behavior of cellulose synthases in Arabidopsis thaliana using confocal microscopy.</a> Methods in Cell Biology. 160, 201-213 (2020).</li><li>Levy, S. E., Myers, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advancements+in+next-generation+sequencing.">Advancements in next-generation sequencing.</a> Annual Review of Genomics and Human Genetics. 17 (1), 95-115 (2016).</li><li>Ooi, C. 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I., Huber, W., Anders, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Moderated+estimation+of+fold+change+and+dispersion+for+RNA-seq+data+with+DESeq2.">Moderated estimation of fold change and dispersion for RNA-seq data with DESeq2.</a> Genome Biology. 15 (12), 550 (2014).</li><li>Kamiya, T., 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+MYB36+transcription+factor+orchestrates+Casparian+strip+formation.">The MYB36 transcription factor orchestrates Casparian strip formation.</a> Proceedings of the National Academy of Sciences of the United States of America. 112 (33), 10533-10538 (2015).</li><li>Zhang, Y., 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=Two+types+of+bHLH+transcription+factor+determine+the+competence+of+the+pericycle+for+lateral+root+initiation.">Two types of bHLH transcription factor determine the competence of the pericycle for lateral root initiation.</a> Nature Plants. 7 (5), 633-643 (2021).</li><li>Haecker, A., 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=Expression+dynamics+of+WOX+genes+mark+cell+fate+decisions+during+early+embryonic+patterning+in+Arabidopsis+thaliana.">Expression dynamics of WOX genes mark cell fate decisions during early embryonic patterning in Arabidopsis thaliana.</a> Development. 131 (3), 657-668 (2004).</li><li>Chen, Q., 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=Auxin+overproduction+in+shoots+cannot+rescue+auxin+deficiencies+in+Arabidopsis+roots.">Auxin overproduction in shoots cannot rescue auxin deficiencies in Arabidopsis roots.</a> Plant Cell Physiol. 55 (6), 1072-1079 (2014).</li><li>Nichterwitz, S., 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=Laser+capture+microscopy+coupled+with+Smart-seq2+for+precise+spatial+transcriptomic+profiling.">Laser capture microscopy coupled with Smart-seq2 for precise spatial transcriptomic profiling.</a> Nature Communications. 7, 12139 (2016).</li><li>Long, J., 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=Nurse+cell--derived+small+RNAs+define+paternal+epigenetic+inheritance+in+Arabidopsis.">Nurse cell--derived small RNAs define paternal epigenetic inheritance in Arabidopsis.</a> Science. 373 (6550), (2021).</li><li>Gutzat, R., 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=Arabidopsis+shoot+stem+cells+display+dynamic+transcription+and+DNA+methylation+patterns.">Arabidopsis shoot stem cells display dynamic transcription and DNA methylation patterns.</a> EMBO Journal. 39 (20), e103667 (2020).</li></ol>

The Smart-seq2-based protocol can generate reliable sequencing libraries from several hundreds of cells8. The quality of the starting material is essential for the accuracy of the transcriptome analysis. FACS is a powerful tool for preparing cells of interest, but this procedure, especially the protoplasting step, must be optimized for plant applications. Laser capture microdissection (LCM) or manual dissected cells can also be used as input25,2...

Cells are the fundamental unit of all living organisms and perform structural and physiological functions. Although the cells in multicellular organisms show apparent synchronicity, cells of different types and individual cells present differences in their transcriptomes during development and environmental responses. High-throughput single-cell RNA sequencing (scRNA-seq) provides unprecedented power for understanding cellular heterogeneity. Applying scRNA-seq in plant sciences has contributed to successfully constructing a plant cell atlas1, has been used to identify rare cellular taxa in plant tissues2, has provided insight into the composition of cell types in plant tissues, and has been used to identify cellular identity and important functions employed during plant development and differentiation. In addition, it is possible to infer spatiotemporal developmental trajectories in plant tissues1,2,3 to discover new marker genes4 and study the functions of important transcription factors5 using scRNA-seq in order to reveal the evolutionary conservation of the same cell type in different plants3. Abiotic stresses are among the most important environmental influences on plant growth and development. By exploring the changes in the composition of cell types in plant tissues under different treatment conditions through single-cell transcriptome sequencing, one can also resolve the abiotic stress response mechanism6.
The potential for resolving transcriptional heterogeneity between cell types using scRNA sequencing depends on the cell isolation method and sequencing platform. Fluorescence-activated cell sorting (FACS) is a widely used technique for isolating a subpopulation of cells for scRNA-seq based on light scattering and the fluorescence properties of the cells. The development of fluorescent marker lines by transgenic technology has greatly improved the efficiency of cell isolation by FACS7. Conducting scRNA-seq using Smart-seq28 further enhances the ability to dissect the cellular heterogeneity. The Smart-seq2 method has good sensitivity for gene detection and can detect genes even with a low transcript input9. In addition to bulk cell type collection, modern cell sorters provide a single-cell index sorting format, allowing transcriptome analysis at single-cell resolution using Smart-seq210 or other multiplexed RNA-seq methods, such as CEL-seq211. Single-cell or cell-type sorting can be potentially used for many other downstream applications, such as parallel multi-omics studies12,13. Presented here is a robust and versatile protocol for isolating plant cell types, such as xylem-pole pericycle cells, lateral root cap cells, lateral root initial cells, cortex cells, and endodermal cells from the roots of Arabidopsis thaliana marker cell lines by FACS. The protocol further involves constructing the Smart-seq2 library for downstream transcriptome analysis.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>0.22 &#181;m strainer</td>
			<td>Sorfa&#160;</td>
			<td>622110</td>
			<td></td>
		</tr>
		<tr>
			<td>Agar</td>
			<td>Yeasen</td>
			<td>70101ES76</td>
			<td></td>
		</tr>
		<tr>
			<td>Agilent fragment analyzer</td>
			<td>Aglient</td>
			<td>Aglient 5200</td>
			<td></td>
		</tr>
		<tr>
			<td>Agilent high-sensitivity DNA kit</td>
			<td>Aglient</td>
			<td>DNF-474-0500</td>
			<td></td>
		</tr>
		<tr>
			<td>Ampure XP beads</td>
			<td>BECKMAN</td>
			<td>A63881</td>
			<td></td>
		</tr>
		<tr>
			<td>Betaine</td>
			<td>yuanye</td>
			<td>S18046-100g</td>
			<td></td>
		</tr>
		<tr>
			<td>Bleach</td>
			<td>Mr Muscle</td>
			<td>FnBn83BK</td>
			<td>20% (v/v) bleach</td>
		</tr>
		<tr>
			<td>BSA</td>
			<td>sigma</td>
			<td>9048-46-8</td>
			<td></td>
		</tr>
		<tr>
			<td>CaCl2</td>
			<td>yuanye</td>
			<td>S24109-500g</td>
			<td></td>
		</tr>
		<tr>
			<td>Cellulase R10</td>
			<td>Yakult (Japan)</td>
			<td>9012-54-8</td>
			<td></td>
		</tr>
		<tr>
			<td>Cellulase RS</td>
			<td>Yakult (Japan)</td>
			<td>9012-54-8</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge tube (1.5 mL)</td>
			<td>Eppendolf</td>
			<td>30121589</td>
			<td></td>
		</tr>
		<tr>
			<td>DNase, RNase, DNA and RNA Away Surface Decontaminants</td>
			<td>Beyotime</td>
			<td>R0127</td>
			<td></td>
		</tr>
		<tr>
			<td>dNTPs (10 mM)</td>
			<td>NEB</td>
			<td>N0447S</td>
			<td></td>
		</tr>
		<tr>
			<td>DTT (0.1 M)</td>
			<td> 
			invitrogen</td>
			<td>18090050</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Sinopharm Chemical Reagent Co., Ltd</td>
			<td>100092680</td>
			<td></td>
		</tr>
		<tr>
			<td>FACS</td>
			<td>BD FACS Melody</td>
			<td>BD-65745</td>
			<td></td>
		</tr>
		<tr>
			<td>FACS</td>
			<td>Sony</td>
			<td>SH800S</td>
			<td></td>
		</tr>
		<tr>
			<td>Filter tip&#160; (1000 &#181;L)</td>
			<td>Thermo Scientific</td>
			<td>TF112-1000-Q</td>
			<td></td>
		</tr>
		<tr>
			<td>Filter tip&#160; (200 &#181;L)</td>
			<td>Thermo Scientific</td>
			<td>TF140-200-Q</td>
			<td></td>
		</tr>
		<tr>
			<td>Filter tip (10 &#181;L)</td>
			<td>Thermo Scientific</td>
			<td>TF104-10-Q</td>
			<td></td>
		</tr>
		<tr>
			<td>Filter tip (100 &#181;L)</td>
			<td>Thermo Scientific</td>
			<td>TF113-100-Q</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluorescent microscope</td>
			<td>Nikon</td>
			<td>Eclipse Ni-E</td>
			<td></td>
		</tr>
		<tr>
			<td>Four-Dimensional Rotating Mixer</td>
			<td>Kylin -Bell</td>
			<td>BE-1100</td>
			<td></td>
		</tr>
		<tr>
			<td>Hemicellulase</td>
			<td>sigma</td>
			<td>9025-56-3</td>
			<td></td>
		</tr>
		<tr>
			<td>IS PCR primer</td>
			<td></td>
			<td></td>
			<td>5&#39;-AAGCAGTGGTATCAACGCAGAG 
			T-3&#39;</td>
		</tr>
		<tr>
			<td>KAPA HiFi HotStart ReadyMix(2X)</td>
			<td>Roche&#160;</td>
			<td>7958935001</td>
			<td></td>
		</tr>
		<tr>
			<td>KCl</td>
			<td>Sinopharm Chemical Reagent Co., Ltd</td>
			<td>7447-40-7</td>
			<td></td>
		</tr>
		<tr>
			<td>Macerozyme R10</td>
			<td>Yakult (Japan)</td>
			<td>9032-75-1</td>
			<td></td>
		</tr>
		<tr>
			<td>Magnetic separation stand</td>
			<td>invitrogen</td>
			<td>12321D</td>
			<td></td>
		</tr>
		<tr>
			<td>Mannitol</td>
			<td>aladdin</td>
			<td>69-65-8</td>
			<td></td>
		</tr>
		<tr>
			<td>MES</td>
			<td>aladdin</td>
			<td>145224948</td>
			<td></td>
		</tr>
		<tr>
			<td>MgCl2&#160;</td>
			<td>yuanye</td>
			<td>R21455-500ml</td>
			<td></td>
		</tr>
		<tr>
			<td>Microcentrifuges</td>
			<td>Eppendorf</td>
			<td>Centrifuge 5425</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro-mini-centrifuge</td>
			<td>Titan</td>
			<td>Timi-10k</td>
			<td></td>
		</tr>
		<tr>
			<td>MS</td>
			<td>Phytotech</td>
			<td>M519</td>
			<td></td>
		</tr>
		<tr>
			<td>Nextera XT DNA Library Preparation Kit</td>
			<td>illumina</td>
			<td>FC-131-1024</td>
			<td></td>
		</tr>
		<tr>
			<td>oligo-dT30VN primer</td>
			<td></td>
			<td></td>
			<td>5&#39;-AAGCAGTGGTATCAACGCAGAG 
			TACTTTTTTTTTTTTTTTTTTTTTTT 
			TTTTTTTTTTVN-3&#39;</td>
		</tr>
		<tr>
			<td>PCR instrument</td>
			<td>Thermal cycler</td>
			<td>A24811</td>
			<td></td>
		</tr>
		<tr>
			<td>Pectolyase</td>
			<td>Yakult (Japan)</td>
			<td>9033-35-6</td>
			<td></td>
		</tr>
		<tr>
			<td>Plant marker lines</td>
			<td>Nottingham Arabidopsis Stock Centre (NASC)</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Qubit 1x dsDNA HS Assay Kit</td>
			<td>invitrogen</td>
			<td>Q33231</td>
			<td></td>
		</tr>
		<tr>
			<td>Qubit 2.0 fluorometer</td>
			<td>invitrogen</td>
			<td>Q32866</td>
			<td></td>
		</tr>
		<tr>
			<td>RNase inhibitor&#160;</td>
			<td>Thermo Scientific</td>
			<td>EO0382</td>
			<td></td>
		</tr>
		<tr>
			<td>RNase-free water</td>
			<td>invitrogen</td>
			<td>10977023</td>
			<td></td>
		</tr>
		<tr>
			<td>Solution A</td>
			<td></td>
			<td></td>
			<td>400 mM mannitol, 0.05 % BSA , 20 mM MES (pH5.7), 10 mM CaCl2, 20 mM KCl</td>
		</tr>
		<tr>
			<td>Solution B</td>
			<td></td>
			<td></td>
			<td>1 % (w/v)cellulase R10, 1 % (w/v) cellulase RS, 1 %&#160; (w/v)hemicellulase, 0.5 %&#160; (w/v)pectolyase and 1 %&#160; (w/v) Macerozyme R10 of in a fresh aliquot of solution A</td>
		</tr>
		<tr>
			<td>Sterile pestle</td>
			<td>BIOTREAT</td>
			<td>453463</td>
			<td></td>
		</tr>
		<tr>
			<td>Strainer (40 &#181;m )</td>
			<td>Sorfa&#160;</td>
			<td>251100</td>
			<td></td>
		</tr>
		<tr>
			<td>Superscript enzyme (200 U/&#181;L)</td>
			<td>invitrogen</td>
			<td>18090050</td>
			<td></td>
		</tr>
		<tr>
			<td>SuperScript VI buffer (5x)</td>
			<td>invitrogen</td>
			<td>18090050</td>
			<td></td>
		</tr>
		<tr>
			<td>T0est tube (5 mL)</td>
			<td>BD Falcon</td>
			<td>352052</td>
			<td></td>
		</tr>
		<tr>
			<td>Thin-walled PCR tubes with caps (0.5 mL)</td>
			<td>AXYGEN</td>
			<td>PCR-05-C</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Sangon Biotech</td>
			<td>A600198-0500</td>
			<td></td>
		</tr>
		<tr>
			<td>TSO primer</td>
			<td></td>
			<td></td>
			<td>5&#39;-AAGCAGTGGTATCAACGCAGAG 
			TACATrGrG+G-3&#39;</td>
		</tr>
		<tr>
			<td>Vortex</td>
			<td>Titan</td>
			<td>VM-T2</td>
			<td></td>
		</tr>
	</tbody>
</table>

isolation and transcriptome analysis of plant cell types

In multicellular organisms, developmental programming and environmental responses can be highly divergent in different cell types or even within cells, which is known as cellular heterogeneity. In recent years, single-cell and cell-type isolation combined with next-generation sequencing (NGS) techniques have become important tools for studying biological processes at single-cell resolution. However, isolating plant cells is relatively more difficult due to the presence of plant cell walls, which limits the application of single-cell approaches in plants. This protocol describes a robust procedure for fluorescence-activated cell sorting (FACS)-based single-cell and cell-type isolation with plant cells, which is suitable for downstream multi-omics analysis and other studies. Using Arabidopsis root fluorescent marker lines, we demonstrate how particular cell types, such as xylem-pole pericycle cells, lateral root initial cells, lateral root cap cells, cortex cells, and endodermal cells, are isolated. Furthermore, an effective downstream transcriptome analysis method using Smart-seq2 is also provided. The cell isolation method and transcriptome analysis techniques can be adapted to other cell types and plant species and have broad application potential in plant science.

Protoplast isolation 
This protocol is effective for the protoplast sorting of fluorescent A. thaliana root marker lines. These markers lines have been developed by the fusion of fluorescent proteins with genes expressed specifically in target cell types, or using enhancer trap lines (Figure 1). Numerous tissues and organs have been dissected into cell types expressing specific fluorescent markers in model plants and crops.
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Isolation and Transcriptome Analysis of Plant Cell Types

The feasibility and effectiveness of high-throughput scRNA-seq methods herald a single-cell era in plant research. Presented here is a robust and complete procedure for isolating specific Arabidopsis thaliana root cell types and subsequent transcriptome library construction and analysis.

In multicellular organisms, developmental programming and environmental responses can be highly divergent in different cell types or even within cells, ...

Transcriptome analysis on single cell or cell types can detect the subtle difference of gene expression being masked by heterogeneity, which is a powerful tool to uncover the elaborate intracellular regulatory mechanisms. Fluorescence activated cell sorting followed by RN-seq analysis can be performed on either single cell or bulk cell type mode with high transcript detection sensitivity and compatibility with other multi-omic approaches. First-time users of this protocol need to pay attention to some steps in the protoplast sorting and RNA-seq library preparation.Along with Jun Zhang, Dr.Rongrong Xie, a post-doc at our laboratory, will help in demonstrating the procedure. To begin, put the Arabidopsis thaliana wild type and fluorescent marker line seeds in 20%bleach and incubate using a rotating incubator at room temperature for 15 minutes to sterilize the seeds. While working on a sterile bench, rinse the seeds three to five times in double distilled water.Plate the wild type and reporter line seeds on half-strength MS medium with 0.8%weight per volume agar. Stratify the plants for two days at four degrees Celsius. Then grow them vertically for five days at 23 degrees Celsius under 16-hour light and 18-hour dark cycles.Gently thaw the protoplasting solutions referred to as solution A and solution B on ice prior to the experiment. Cut off the roots from the plants using a clean blade or scissors and chop the roots into approximately 0.5 centimeter pieces. Submerge the chopped roots in 1.5 milliliters of solution B followed by gentle rotation at room temperature for 1.5 to 2 hours.Filter the resulting root protoplasts through a 40 micron strainer mesh and rinse the mesh with one to two milliliters of solution A.Centrifuge the combined filtrates at 300 G for five minutes at four degrees Celsius. Discard the supernatant using a pipette, resuspend the cell pellet in 500 to 600 microliters of solution A, and place it on ice immediately. For cell sorting, transfer the resuspended cell solution to a new five milliliter test tube.Fill the sheath fluid tank and check the waste tank. Then switch on the fluorescence-activated cell sorting or FACS machine. Carry out the instrument setup and auto-calibration steps on the sorter.Select the fluorescence channels and use a wild type plant with no fluorescence as a baseline control. Adjust the sorting gate based on the fluorescence intensity and forward scatter and side scatter singlets. After adding 500 microliters of solution A into a 1.5 milliliter collection tube, start sorting and collect 2, 000 to 3, 000 cells per tube.After sorting, immediately place the samples on ice. Centrifuge the collection tube containing the cells at 300 G and four degrees Celsius for five minutes and remove the supernatant with a pipette. Take two microliters of sorted cells and check for fluorescence using a fluorescence microscope.Store the sorted cells at minus 80 degrees Celsius if not used immediately. For single cell index sorting, place the 96-well plate with membrane into the adapter. Calibrate the position of the plate so that the droplet falls in the center hole of the plate.Remove the membrane from the 96-well plate and place the 96-well plate into the adapter. Select single cell sorting mode when sorting. Enter the target number of sorted cells as one and start sorting.Before beginning the experiment, clean the bench with a surface decontaminant and 75%ethanol. Use all equipment only for sequencing library preparation. After adding one microliter of freshly prepared mixture A into the sorted sample, grind it with a sterile pestle.Using RNAse free water, make up the volume to 14 microliters. Then transfer each sample into 0.2 milliliter thin walled PCR tube. Then prepare mixture B.Add 4.4 microliters in mixture B to each PCR tube containing samples and mix by gentle pipetting.Incubate the samples at 72 degrees Celsius for three minutes. After incubation, immediately put the samples on ice to hybridize the oligo dT to the poly-A tail. Prepare the reverse transcription reaction mixture or mixture C in a 21.6 microliters of it to each tube containing the samples.Subject the samples to reverse transcription reaction in a common PCR instrument per the reverse transcription program. Add 40.8 microliters of the freshly prepared pre-amplification reaction mixture or mixture D to the reverse transcription reaction product and run the pre-amplification program. The amplification cycle can be determined by quantitative PCR when the reaction just enters the exponential phase.To purify the pre-amplification reaction products, transfer the pre-amplified products from a PCR tube to a 1.5 milliliter tube. Add 48 microliters of AMPure XP beads into each sample and gently mixed by pipetting before incubation. Place the 1.5 milliliter tubes containing the samples and beads on a magnetic separation stand for five minutes.Carefully discard the supernatant from the samples without disturbing the beads. After resuspending them in 200 microliters of 80%ethanol, place them on the magnetic separation stand for another three minutes. After discarding the ethanol containing supernatant, air dry the samples in a tube for 10 minutes.Resuspend the beads in 20 microliters of nuclease free water and incubate at room temperature for five minutes. Then place them on the magnetic separation stand for five minutes. Using a pipette, transfer 18 microliters of the supernatant from each tube into a new 1.5 milliliter centrifuge tube.Finally, follow the steps described in the text to characterize the pre-library, followed by library construction, purification, and quantification. The fluorescent Arabidopsis thaliana markers lines were developed by fusing fluorescent proteins with genes expressed specifically in target cell types or by using enhancer trap lines. The fluorescence-specific marked protoplasts were successfully sorted based on the fluorescence intensity and forward scatter and side scatter singlets.The sorted cells were visualized using brightfield and fluorescence imaging. The representative results of the RNA-sequencing library of about 2, 000 xylem pole pericycle cells, lateral root primordial cells, endodermis or cortex cells, and lateral root cap cells are shown. A small sized library with primer or adapter dimer peaks could still be sequenced after size selection.A library with an abnormal size distribution indicated unsuccessful library preparation. The gene expression patterns were analyzed. The genes enriched in any of the four root cell types were clustered and depicted in a heat map showing the specificity of gene expressions among different cell types.High quality and purity of target cells through correct gating and sorting and prevention of RNA degradation are key to successful library construction. For RNA-seq in the single cell mode, several methods integrated with the unique molecular identifier have been reported recently which significantly improved the performance.

isolation-and-transcriptome-analysis-of-plant-cell-types

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Biology

1.2K Views.  Shanghai Jiao Tong University. L'analisi del trascrittoma su singole cellule o tipi di cellule può rilevare la sottile differenza di espressione genica mascherata dall'eterogeneità, che è un potente strumento per scoprire gli elaborati meccanismi di regolazione intracellulare. La selezione delle cellule attivate dalla fluorescenza seguita dall'analisi RN-seq può essere eseguita in modalità singola cella o bulk cell type con elevata sensibilità di rilevamento della trascrizione e compatibilità con altri approcci mult...