Work in the Montgomery lab on phytochrome responses in plants is supported by the National Science Foundation (grant no. MCB-0919100 to B.L.M.) and the Chemical Sciences, Geosciences and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy (grant no. DE FG02 91ER20021 to B.L.M.). We thank Melissa Whitaker for technical assistance during filming and critically reading the manuscript, Stephanie Costigan for experimental assistance, Dr. Louis King for assistance with developing and optimizing Fluorescence-Activated Cell Sorting protocols for Arabidopsis protoplast sorting and Dr. Melinda Frame for assistance with confocal microscopy. We thank Marlene Cameron for graphical design assistance and Karen Bird for editorial assistance.

1. Plant Growth
<ol>
 <li>Confirmed UAS-BVR X GAL4-GFP enhancer trap line isolated as described4 (For summary see Fig. 1) and wild-type or parental lines are sown on soil, i.e. ~2000 sterilized seeds per line. </li>
 <li>Plants are grown for 5 weeks on soil under white illumination of 100 &mu;molm-2s-1 at 22 &deg;C and 70% humidity.</li>
</ol>
2. Leaf Protoplast Isolation (adapted from Denecke and Vitale9)
<ol>
 <li>To isolate protoplas...

<ol>
	<li>Franklin, K. A., Quail, P. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phytochrome+functions+in+Arabidopsis+development.">Phytochrome functions in Arabidopsis development.</a> J. Exp. Bot. 61, 11-24 (2010).</li><li>Montgomery, B. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Right+place,+right+time:+Spatiotemporal+light+regulation+of+plant+growth+and+development.">Right place, right time: Spatiotemporal light regulation of plant growth and development.</a> Plant Signal Behav. 3, 1053-1060 (2008).</li><li>Laplaze, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=GAL4-GFP+enhancer+trap+lines+for+genetic+manipulation+of+lateral+root+development+in+Arabidopsis+thaliana.">GAL4-GFP enhancer trap lines for genetic manipulation of lateral root development in Arabidopsis thaliana.</a> J. Exp. Bot. 56, 2433-2442 (2005).</li><li>Costigan, S., Warnasooriya, S. N., Montgomery, B. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Root-localized+phytochrome+chromophore+synthesis+is+required+for+tissue-specific+photoregulation+of+root+elongation+and+impacts+sensitivity+to+jasmonic+acid+in+Arabidopsis+thaliana.">Root-localized phytochrome chromophore synthesis is required for tissue-specific photoregulation of root elongation and impacts sensitivity to jasmonic acid in Arabidopsis thaliana.</a> , .</li><li>Lagarias, D. M., Crepeau, M. W., Maines, M. D., Lagarias, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+photomorphogenesis+by+expression+of+mammalian+biliverdin+reductase+in+transgenic+Arabidopsis+plants.">Regulation of photomorphogenesis by expression of mammalian biliverdin reductase in transgenic Arabidopsis plants.</a> Plant Cell. , 675-688 (1997).</li><li>Montgomery, B. L., Yeh, K. C., Crepeau, M. W., Lagarias, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modification+of+distinct+aspects+of+photomorphogenesis+via+targeted+expression+of+mammalian+biliverdin+reductase+in+transgenic+Arabidopsis+plants.">Modification of distinct aspects of photomorphogenesis via targeted expression of mammalian biliverdin reductase in transgenic Arabidopsis plants.</a> Plant Physiol. 121, 629-639 (1999).</li><li>Warnasooriya, S. N., Montgomery, B. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+spatial-specific+phytochrome+responses+using+targeted+expression+of+biliverdin+reductase+in+Arabidopsis.">Detection of spatial-specific phytochrome responses using targeted expression of biliverdin reductase in Arabidopsis.</a> Plant Physiol. 149, 424-433 (2009).</li><li>Warnasooriya, S. N., Porter, K. J., Montgomery, B. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Light-dependent+anthocyanin+accumulation+and+phytochromes+in+Arabidopsis+thaliana.">Light-dependent anthocyanin accumulation and phytochromes in Arabidopsis thaliana.</a> , .</li><li>Denecke, J., Vitale, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+use+of+protoplasts+to+study+protein+synthesis+and+transport+by+the+plant+endomembrane+system.">The use of protoplasts to study protein synthesis and transport by the plant endomembrane system.</a> Methods Cell Biol. 50, 335-348 (1995).</li><li>Birnbaum, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+type-specific+expression+profiling+in+plants+via+cell+sorting+of+protoplasts+from+fluorescent+reporter+lines.">Cell type-specific expression profiling in plants via cell sorting of protoplasts from fluorescent reporter lines.</a> Nat. Methods. 2, 615-619 (2005).</li><li>Ma, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Light+control+of+Arabidopsis+development+entails+coordinated+regulation+of+genome+expression+and+cellular+pathways.">Light control of Arabidopsis development entails coordinated regulation of genome expression and cellular pathways.</a> Plant Cell. 13, 2589-2607 (2001).</li><li>Chen, M., Chory, J., Fankhauser, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Light+signal+transduction+in+higher+plants.">Light signal transduction in higher plants.</a> Annu. Rev. Genet. 38, 87-117 (2004).</li><li>Ulm, R., &amp;amp, N. a. g. y., F, . <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Signalling+and+gene+regulation+in+response+to+ultraviolet+light.">Signalling and gene regulation in response to ultraviolet light.</a> Curr. Opin. Plant Biol. 8, 477-482 (2005).</li><li>Ma, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organ-specific+expression+of+Arabidopsis+genome+during+development.">Organ-specific expression of Arabidopsis genome during development.</a> Plant Physiol. 138, 80-91 (2005).</li><li>Neff, M. M., Fankhauser, C., &amp;amp, C. h. o. r. y., J, . <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Light:+an+indicator+of+time+and+place.">Light: an indicator of time and place.</a> Genes Dev. 14, 257-271 (2000).</li><li>Birnbaum, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+gene+expression+map+of+the+Arabidopsis+root.">A gene expression map of the Arabidopsis root.</a> Science. 302, 1956-1960 (2003).</li></ol>

Gene expression profiling through microarrays (1) has indicated that more than 30% of the genes in Arabidopsis seedlings are light regulated11 and (2) has identified a vast group of genes encoding light signal transduction proteins involved in the phytochrome signaling cascade12, 13. Such experiments suggest that light induces rapid and long-term changes in gene expression. Each pool of phytochromes may control only a subset of developmental and adaptive responses. Moreover, it is likely that downst...

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Anti-BVR antibody</td>
<td>&nbsp;</td>
<td>QED Bioscience Inc.</td>
<td>56257-100</td>
<td>&nbsp;</td>
<tr>
<td>Cellulase &#x201C;Onozuka&#x201D; R-10</td>
<td>&nbsp;</td>
<td>SERVA Electrophoresis GmbH, Crescent Chemical Company</td>
<td>MSPC 0930</td>
<td>&nbsp;</td>
<tr>
<td>Gamborg&#x2019;s B5 basal salt mixture</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>G5768</td>
<td>&nbsp;</td>
<tr>
<td>Macerozyme R-10</td>
<td>&nbsp;</td>
<td>SERVA Electrophoresis GmbH, Crescent Chemical Company</td>
<td>PTC 001</td>
<td>&nbsp;</td>
<tr>
<td>MES, low moisture content</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>M3671</td>
<td>&nbsp;</td>
<tr>
<td>Murashige and Skoog salts</td>
<td>&nbsp;</td>
<td>Caisson Laboratories</td>
<td>74904</td>
<td>&nbsp;</td>
<tr>
<td>Phytablend</td>
<td>&nbsp;</td>
<td>Caisson Laboratories</td>
<td>28302</td>
<td>&nbsp;</td>
<tr>
<td>RNeasy Plant Minikit</td>
<td>&nbsp;</td>
<td>Qiagen</td>
<td>16419</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

investigating tissue- and organ-specific phytochrome responses using facs-assisted cell-type specific expression profiling in arabidopsis thaliana

Light mediates an array of developmental and adaptive processes throughout the life cycle of a plant. Plants utilize light-absorbing molecules called photoreceptors to sense and adapt to light. The red/far-red light-absorbing phytochrome photoreceptors have been studied extensively. Phytochromes exist as a family of proteins with distinct and overlapping functions in all higher plant systems in which they have been studied1. Phytochrome-mediated light responses, which range from seed germination through flowering and senescence, are often localized to specific plant tissues or organs2. Despite the discovery and elucidation of individual and redundant phytochrome functions through mutational analyses, conclusive reports on distinct sites of photoperception and the molecular mechanisms of localized pools of phytochromes that mediate spatial-specific phytochrome responses are limited. We designed experiments based on the hypotheses that specific sites of phytochrome photoperception regulate tissue- and organ-specific aspects of photomorphogenesis, and that localized phytochrome pools engage distinct subsets of downstream target genes in cell-to-cell signaling. We developed a biochemical approach to selectively reduce functional phytochromes in an organ- or tissue-specific manner within transgenic plants. Our studies are based on a bipartite enhancer-trap approach that results in transactivation of the expression of a gene under control of the Upstream Activation Sequence (UAS) element by the transcriptional activator GAL43. The biliverdin reductase (BVR) gene under the control of the UAS is silently maintained in the absence of GAL4 transactivation in the UAS-BVR parent4. Genetic crosses between a UAS-BVR transgenic line and a GAL4-GFP enhancer trap line result in specific expression of the BVR gene in cells marked by GFP expression4. BVR accumulation in Arabidopsis plants results in phytochrome chromophore deficiency in planta5-7. Thus, transgenic plants that we have produced exhibit GAL4-dependent activation of the BVR gene, resulting in the biochemical inactivation of phytochrome, as well as GAL4-dependent GFP expression. Photobiological and molecular genetic analyses of BVR transgenic lines are yielding insight into tissue- and organ-specific phytochrome-mediated responses that have been associated with corresponding sites of photoperception4, 7, 8. Fluorescence Activated Cell Sorting (FACS) of GFP-positive, enhancer-trap-induced BVR-expressing plant protoplasts coupled with cell-type-specific gene expression profiling through microarray analysis is being used to identify putative downstream target genes involved in mediating spatial-specific phytochrome responses. This research is expanding our understanding of sites of light perception, the mechanisms through which various tissues or organs cooperate in light-regulated plant growth and development, and advancing the molecular dissection of complex phytochrome-mediated cell-to-cell signaling cascades.

Watch this Scientific Journal Video about Investigating Tissue- and Organ-specific Phytochrome Responses using FACS-assisted Cell-type Specific Expression Profiling in Arabidopsis thaliana at JoVE.com

Investigating Tissue- and Organ-specific Phytochrome Responses using FACS-assisted Cell-type Specific Expression Profiling in Arabidopsis thaliana

The molecular basis of spatial-specific phytochrome responses is being investigated using transgenic plants that exhibit tissue- and organ-specific phytochrome deficiencies. The isolation of specific cells exhibiting induced phytochrome chromophore depletion by Fluorescence-Activated Cell Sorting followed by microarray analyses is being utilized to identify genes involved in spatial-specific phytochrome responses.

Investigating Tissue- and Organ-specific Phytochrome Responses using FACS-assisted Cell-type Specific Expression Profiling in Arabidopsis thaliana

Light mediates an array of developmental and adaptive processes throughout the life cycle of a plant. Plants utilize light-absorbing molecules called ...

investigating-tissue-organ-specific-phytochrome-responses-using-facs

Research

JoVE Journal

Biology

15.7K visualizações.  Michigan State University (MSU). A base molecular do espaço-respostas específicas fitocromo está sendo investigado o uso de plantas transgênicas que apresentam tecidos e órgãos específicos deficiências fitocromo. O isolamento de células específicas exibindo esgotamento cromóforo fitocromo induzida por fluorescência-Activated Celular classificação seguido por análises de microarray está sendo utilizada para identificar genes envolvidos em respostas espaciais específicos fitocromo.

Vídeo: Investigating Tissue- and Organ-specific Phytochrome Responses using FACS-assisted Cell-type Specific Expression Profiling in Arabidopsis thaliana