This work was partially supported by the Direcci&#243;n General de Asuntos del Personal Acad&#233;mico, DGAPA/PAPIIT-UNAM (grant no. IN219916 to M.L and IA205117 to M-K.A) and the Consejo Nacional de Ciencia y Tecnol&#242;gia (CONACYT grant no. 240614 to M.L.).

1. Identification, Isolation, and Cloning of P. Vulgaris NIN Promoter
<ol>
	<li>Identify the promoter sequence for the gene of interest. There are several genome databases and analysis tools available for plants such as Phytozome, Ensembl Plants, NCBI, etc. A legume promoter P. vulgaris NIN (PvNIN; Phvul.009G115800) was used in this study20.</li>
	<li>Design oligos either for Gateway or traditional restriction enzyme cloning depending on the vector system used (<strong...

<ol>
	<li>Hern&#225;ndez-Garcia, C. M., Finer, 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=Identification+and+validation+of+promoters+and+cis-actingregulatory+elements.">Identification and validation of promoters and cis-actingregulatory elements.</a> Plant Science. 217-218, 109-119 (2014).</li><li>Dhanapal, A. P., Govindaraj, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unlimited+Thirst+for+Genome+Sequencing,+Data+Interpretation,+and+Database+Usage+in+Genomic+Era:+The+Road+towards+Fast-Track+Crop+Plant+Improvement.">Unlimited Thirst for Genome Sequencing, Data Interpretation, and Database Usage in Genomic Era: The Road towards Fast-Track Crop Plant Improvement.</a> Genetics Research International. , 684321 (2015).</li><li>Nanjareddy, N., Arthikala, M. K., Blanco, L., Arellano, E. S., Lara, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protoplast+isolation,+transient+transformation+of+leaf+mesophyll+protoplasts+and+improved+Agrobacterium-mediated+leaf+disc+infiltration+of+Phaseolus+vulgaris:+Tools+for+rapid+gene+expression+analysis.">Protoplast isolation, transient transformation of leaf mesophyll protoplasts and improved Agrobacterium-mediated leaf disc infiltration of Phaseolus vulgaris: Tools for rapid gene expression analysis.</a> BMC Biotechnol. 16 (1), 53 (2016).</li><li>Pumplin, N., Zhang, X., Noar, R. D., Harrison, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polar+localization+of+a+symbiosis-specific+phosphate+transporter+is+mediated+by+a+transient+reorientation+of+secretion.">Polar localization of a symbiosis-specific phosphate transporter is mediated by a transient reorientation of secretion.</a> Proc Natl Acad Sci U S A. 109 (11), E665-E672 (2012).</li><li>Kryvoruchko, I. 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=MtSWEET11,+a+Nodule-Specific+Sucrose+Transporter+of+Medicago+truncatula.">MtSWEET11, a Nodule-Specific Sucrose Transporter of Medicago truncatula.</a> Plant Physiol. 171 (1), 554-565 (2016).</li><li>Suzaki, T., Yano, K., Ito, M., Umehara, Y., Suganuma, N., Kawaguchi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Positive+and+negative+regulation+of+cortical+cell+division+during+root+nodule+development+in+Lotus+japonicus+is+accompanied+by+auxin+response.">Positive and negative regulation of cortical cell division during root nodule development in Lotus japonicus is accompanied by auxin response.</a> Development. 139 (21), 3997-4006 (2012).</li><li>Suzaki, 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=Endoreduplication-mediated+initiation+of+symbiotic+organ+development+in+Lotus+japonicus.">Endoreduplication-mediated initiation of symbiotic organ development in Lotus japonicus.</a> Development. 141 (12), 2441-2445 (2014).</li><li>Qin, 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+high-affinity+phosphate+transporter+GmPT5+regulates+phosphate+transport+to+nodules+and+nodulation+in+soybean.">The high-affinity phosphate transporter GmPT5 regulates phosphate transport to nodules and nodulation in soybean.</a> Plant Physiol. 159 (4), 1634-1643 (2012).</li><li>Wang, Z., Panfeng, L., Yan, Y., Chi, Y., Fan, B., Chen, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+and+Functional+Analysis+of+a+Novel+Group+of+Legume-specific+WRKY+and+Exo70+Protein+Variants+from+Soybean.">Expression and Functional Analysis of a Novel Group of Legume-specific WRKY and Exo70 Protein Variants from Soybean.</a> Sci Rep. 6, 32090 (2016).</li><li>Montiel, 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=A+Phaseolus+vulgaris+NADPH+oxidase+gene+is+required+for+root+infection+by+Rhizobia.">A Phaseolus vulgaris NADPH oxidase gene is required for root infection by Rhizobia.</a> Plant Cell Physiol. 53 (10), 1751-1767 (2012).</li><li>Arthikala, M. K., 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=PvRbohB+negatively+regulates+Rhizophagus+irregularis+colonization+in+Phaseolus+vulgaris.">PvRbohB negatively regulates Rhizophagus irregularis colonization in Phaseolus vulgaris.</a> Plant Cell Physiol. 54 (8), 1391-1402 (2013).</li><li>Arthikala, M. K., S&#225;nchez-L&#243;pez, R., Nava, N., Santana, O., C&#225;rdenas, L., Quinto, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RbohB+a+Phaseolus+vulgaris+NADPH+oxidase+gene,+enhances+symbiosome+number,+bacteroid+size,+and+nitrogen+fixation+in+nodules+and+impairs+mycorrhizal+colonization.">RbohB a Phaseolus vulgaris NADPH oxidase gene, enhances symbiosome number, bacteroid size, and nitrogen fixation in nodules and impairs mycorrhizal colonization.</a> New Phytol. 202 (3), 886-900 (2014).</li><li>Barraza, 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=Down-regulation+of+PvTRE1+enhances+nodule+biomass+and+bacteroid+number+in+the+common+bean.">Down-regulation of PvTRE1 enhances nodule biomass and bacteroid number in the common bean.</a> New Phytol. 197 (1), 194-206 (2013).</li><li>Estrada-Navarrete, G., 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=An+autophagy-related+kinase+is+essential+for+the+symbiotic+relationship+between+Phaseolus+vulgaris+and+both+rhizobia+and+arbuscular+mycorrhizal+fungi.">An autophagy-related kinase is essential for the symbiotic relationship between Phaseolus vulgaris and both rhizobia and arbuscular mycorrhizal fungi.</a> Plant Cell. 28 (9), 2326-2341 (2016).</li><li>Nanjareddy, K., 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+Legume+TOR+Protein+Kinase+Regulates+Rhizobium+Symbiosis+and+Is+Essential+for+Infection+and+Nodule+Development.">A Legume TOR Protein Kinase Regulates Rhizobium Symbiosis and Is Essential for Infection and Nodule Development.</a> Plant Physiol. 172 (3), 2002-2020 (2016).</li><li>Fr&#252;hling, M., Schr&#246;der, G., Hohnjec, N., P&#252;hler, A., Perlick, A. M., K&#252;ster, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+promoter+of+the+Vicia+faba+L.+gene+VfEnod12+encoding+an+early+nodulin+is+active+in+cortical+cells+and+nodule+primordia+of+transgenic+hairy+roots+of+Vicia+hirsuta+as+well+as+in+the+prefixing+zone+II+of+mature+transgenic+V.+hirsuta+root+nodules.">The promoter of the Vicia faba L. gene VfEnod12 encoding an early nodulin is active in cortical cells and nodule primordia of transgenic hairy roots of Vicia hirsuta as well as in the prefixing zone II of mature transgenic V. hirsuta root nodules.</a> Plant Science. 160 (1), 67-75 (2000).</li><li>Szabados, L., Ratet, P., Grunenberg, B., de Bruijn, F. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+analysis+of+the+Sesbania+rostrata+leghemoglobin+glb3+gene+5'-upstream+region+in+transgenic+Lotus+corniculatus+and+Nicotiana+tabacum+plants.">Functional analysis of the Sesbania rostrata leghemoglobin glb3 gene 5'-upstream region in transgenic Lotus corniculatus and Nicotiana tabacum plants.</a> Plant Cell Online. 2 (10), 973-986 (1990).</li><li>Madsen, L. H., Tirichine, L., Jurkiewicz, A., Sullivan, J. T., Heckmann, A. B., Bek, A. S., Ronson, C. W., James, E. K., Stougaard, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+molecular+network+governing+nodule+organogenesis+and+infection+in+the+model+legume+Lotus+japonicus.">The molecular network governing nodule organogenesis and infection in the model legume Lotus japonicus.</a> Nat Commun. 12, 1-10 (2010).</li><li>Montiel, J., Arthikala, M. K., Quinto, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phaseolus+vulgaris+RbohB+functions+in+lateral+root+development.">Phaseolus vulgaris RbohB functions in lateral root development.</a> Plant Signal Behav. 8 (1), 1-3 (2013).</li><li>Nanjareddy, K., Arthikala, M. K., G&#243;mez, B. M., Blanco, L., Lara, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differentially+expressed+genes+in+mycorrhized+and+nodulated+roots+of+common+bean+are+associated+with+defense,+cell+wall+architecture,+N+metabolism,+and+P+metabolism.">Differentially expressed genes in mycorrhized and nodulated roots of common bean are associated with defense, cell wall architecture, N metabolism, and P metabolism.</a> PLoS ONE. 12 (8), e0182328 (2017).</li><li>Karimi, M., Inz&#233;, D., Depicker, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gateway+vectors+for+Agrobacterium-mediated+plant+transformation.">Gateway vectors for Agrobacterium-mediated plant transformation.</a> Trends Plant Sci. 7 (5), 193-195 (2002).</li><li>Broughton, W. J., Dilworth, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Control+of+leghemoglobin+synthesis+in+snake+beans.">Control of leghemoglobin synthesis in snake beans.</a> Biochem J. 125 (4), 1075-1080 (1971).</li><li>Jefferson, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assaying+chimeric+genes+in+plants,+the+GUS+gene+fusion+system.">Assaying chimeric genes in plants, the GUS gene fusion system.</a> Plant Mol Biol Rep. 5 (4), 387-405 (1987).</li><li>Cho, H. J., Farrand, S. K., Noel, G. R., Widholm, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-efficiency+induction+of+soybean+hairy+roots+and+propagation+of+the+soybean+cyst+nematode.">High-efficiency induction of soybean hairy roots and propagation of the soybean cyst nematode.</a> Planta. 210 (2), 195-204 (2000).</li><li>Deng, Y., Mao, G., Stutz, W., Yu, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+Composite+Plants+in+Medicago+truncatula+used+for+Nodulation+Assays.">Generation of Composite Plants in Medicago truncatula used for Nodulation Assays.</a> J. Vis. Exp. (49), e2633 (2011).</li><li>Kumagai, H., Kouchi, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gene+silencing+by+expression+of+hairpin+RNA+in+Lotus+japonicus+roots+and+root+nodules.">Gene silencing by expression of hairpin RNA in Lotus japonicus roots and root nodules.</a> Mol Plant Microbe Interact. 16 (8), 663-668 (2003).</li><li>Okamoto, S., Yoro, E., Suzaki, T., Kawaguchi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hairy+Root+Transformation+in+Lotus+japonicus.">Hairy Root Transformation in Lotus japonicus.</a> Bio-protocol. 3 (12), e795 (2013).</li><li>Jacobs, T. B., Martin, G. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-throughput+CRISPR+Vector+Construction+and+Characterization+of+DNA+Modifications+by+Generation+of+Tomato+Hairy+Roots.">High-throughput CRISPR Vector Construction and Characterization of DNA Modifications by Generation of Tomato Hairy Roots.</a> J. Vis. Exp. (110), e53843 (2016).</li><li>Estrada-Navarrete, G., 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=Agrobacterium+rhizogenes-transformation+of+the+Phaseolus+spp.:+a+tool+for+functional+genomics.">Agrobacterium rhizogenes-transformation of the Phaseolus spp.: a tool for functional genomics.</a> Mol Plant Microbe Interact. 19 (12), 1385-1393 (2006).</li></ol>

During functional analysis of genes, the study of gene expression patterns plays a crucial role in understanding the spatial and temporal regulation of the genes in vivo. A well-known method to study gene expression patterns is to clone the gene promoter region of interest, upstream to reporter genes such as fluorescent marker genes (GFP, RFP, etc.) or &#946;-glucuronidase. Herein, we have selected a promoter region of the root nodule symbiosis (RNS) specific gene, NIN, to study the spatio-temporal expr...

Promoters are important molecular biological tools which play a crucial role in understanding the regulation of the expression of genes of interest. Promoters are DNA sequences located upstream of the translation initiation codon of gene sequences and they carry the central regulatory information of genes; therefore, their correct annotation and characterization are vital to understanding gene function. Depending on the expression patterns, plant promoters are classified as constitutive, tissue-specific, or development-stage-specific and inducible1. Advances in transcriptomic technologies, improvements in computer modeling, and the availability of increasing numbers of genome sequences for different plant species have facilitated the large-scale prediction of promoter sequences2.
On the other hand, it is also critical to establish promoter evaluation tools and genetic transformation techniques that are fast, efficient, and reproducible. Unlike the other model plants, the functional characterization of common bean legume (P. vulgaris) genes is impeded chiefly due to the recalcitrant nature of Phaseolus sp. for stable genetic transformation. Transient transformation systems serve as an alternative for rapid gene functional characterization studies3. In legume symbiosis research, the interaction between the legume host plant and rhizobial bacterium is one of the most tractable model systems for the functional analysis of nodule-specific genes and promoter studies. So far, several legume promoters related to these symbioses have been characterized, viz., Medicago truncatula PT44, SWEET115, Lotus japonicus Cyclops, UBQ6, VAG17, Glycine max PT58, Exo70J9, P. vulgaris RbohB10,11,12, TRE113, PI3K14, TOR15, etc.Cis elements directly influence gene regulation. The transcription factor ENBP1A binds to a Cis regulatory region (&#8722;692 bp) of early nodulin VfENOD12, and this facilitates the expression of a reporter gene in nodule primordia of Vicia faba16. Replacement of Cis regulatory regions (&#8722;161 to &#8722;48 bp) of the nodule-specific promoter leghemoglobin GLB3 with the heterologous truncated promoters &#948;-p35S and &#948;-pNOS, resulted in a loss of nodule specificity and reduced promoter activity17.
Previous reports show that the transcription factor NIN is required for the initiation of rhizobial infection in the root hair cells and is also essential for nodule organogenesis in L. japonicus18. In the present study, we describe a protocol for identification, isolation, cloning, and characterization of nodule-specific promoter in the common bean hairy roots. To achieve this, we selected a rhizobial symbiosis-specific NIN promoter of P. vulgaris and cloned in a transcriptional fusion to the chimeric reporter GUS-enhanced::GFP. Further, this protocol describes a rapid and versatile system of genetic transformation in the P. vulgaris using A. rhizogenes induced hairy roots. This system generates hairy roots in less than 2 weeks after transformation. Finally, we assessed the spatiotemporal expression of NIN promoter in rhizobia colonized root nodules by GUS staining.
The procedure described here may be useful not only for the study of nodulation and mycorrhization11 of legume plants, but also for the study of promoter expression patterns in roots19. Moreover, this protocol is easy to use in non-specialized laboratories.

<table border="0" cellpadding="0" cellspacing="0" width="1125">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Primers for qRT-PCR assay</td>
			<td style="width:253px;"></td>
			<td style="width:460px;"></td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">pNIN Forward</td>
			<td>CACC ATA GCT CCC CAA AAT GGT AT</td>
			<td style="width:460px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">pNIN Reverse</td>
			<td style="width:253px;">CAT CTT CCT TCC ACT AAC TAA C</td>
			<td style="width:460px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">M13 Forward</td>
			<td>GTA AAA CGA CGG CCA G</td>
			<td style="width:460px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">M13 Reverse</td>
			<td>CAG GAA ACA GCT ATG AC</td>
			<td style="width:460px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Name</td>
			<td style="width:253px;">Company</td>
			<td style="width:460px;">Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">REAGENTS</td>
			<td style="width:253px;"></td>
			<td style="width:460px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">pENTR/D-TOPO Cloning Kit</td>
			<td style="width:253px;">Invitrogen</td>
			<td style="width:460px;">K243520</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Gateway LR Clonase II Enzyme Mix&#160;</td>
			<td style="width:253px;">Invitrogen</td>
			<td style="width:460px;">11791100</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;">pBGWFS7.0&#160;</td>
			<td style="width:253px;">Plant systems biology</td>
			<td style="width:460px;">https://gateway.psb.ugent.be/vector/show/pBGWFS7/search/index/</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Platinum Taq DNA Polymerase</td>
			<td style="width:253px;">ThermoFisher Scientific</td>
			<td style="width:460px;">10966018</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">DNeasy Plant Mini Kit</td>
			<td style="width:253px;">Qiagen</td>
			<td>69104</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">PureLink Quick Gel Extraction Kit</td>
			<td style="width:253px;">ThermoFisher Scientific</td>
			<td style="width:460px;">K210012</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Platinum Pfx DNA Polymerase</td>
			<td style="width:253px;">Invitrogen</td>
			<td style="width:460px;">11708013</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:245px;">Certified Molecular Biology Agarose</td>
			<td style="width:253px;">Bio-Rad</td>
			<td>1613102</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:245px;">One Shot TOP10 Chemically Competent E. coli</td>
			<td style="width:253px;">Invitrogen</td>
			<td style="width:460px;">C404006</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Nacl</td>
			<td style="width:253px;">Sigma-Aldrich</td>
			<td style="width:460px;">S7653</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Tryptone</td>
			<td style="width:253px;">Sigma-Aldrich</td>
			<td style="width:460px;">T7293-250G</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Yeast extract</td>
			<td style="width:253px;">Sigma-Aldrich</td>
			<td style="width:460px;">Y1625-250G</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Bacteriological agar</td>
			<td style="width:253px;">Sigma-Aldrich</td>
			<td style="width:460px;">A5306-1KG</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Kanamycin sulfate</td>
			<td style="width:253px;">Sigma-Aldrich</td>
			<td style="width:460px;">60615-25G</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Spectinomycin sulfate</td>
			<td style="width:253px;">Sigma-Aldrich</td>
			<td>PHR1441</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Ethyl alcohol</td>
			<td style="width:253px;">Sigma-Aldrich</td>
			<td>E7023</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Bacteriological peptone</td>
			<td style="width:253px;">Sigma-Aldrich</td>
			<td style="width:460px;">P0556</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Calcium chloride</td>
			<td style="width:253px;">Sigma-Aldrich</td>
			<td style="width:460px;">C1016</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Nalidixic acid</td>
			<td style="width:253px;">Sigma-Aldrich</td>
			<td style="width:460px;">N8878</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Magnesium sulfate</td>
			<td style="width:253px;">Sigma-Aldrich</td>
			<td style="width:460px;">M7506</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Gel loading solution</td>
			<td style="width:253px;">Sigma-Aldrich</td>
			<td style="width:460px;">G7654</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Name</td>
			<td style="width:253px;">Company</td>
			<td style="width:460px;">Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">EQUIPMENT</td>
			<td style="width:253px;"></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Thermocycler</td>
			<td style="width:253px;">Veriti Thermal Cycler</td>
			<td style="width:460px;">4375786</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Centrifuge</td>
			<td style="width:253px;">Sigma</td>
			<td style="width:460px;">Sigma 1-14K</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Gel documentation unit</td>
			<td style="width:253px;">Carestream&#160;</td>
			<td style="width:460px;">Gel Logic 212 PRO</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:245px;">MaxQ SHKE6000 6000 Shaking Incubator - 115VAC</td>
			<td style="width:253px;">Thermo scientific</td>
			<td style="width:460px;">EW-51708-70</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Plant growth chamber</td>
			<td style="width:253px;">MRC</td>
			<td>PGI-550RH&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Horizantal laminarair flow cabinate</td>
			<td style="width:253px;">Lumistell</td>
			<td style="width:460px;">LH-120</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Fluorescent microscope</td>
			<td style="width:253px;">Leica&#160;</td>
			<td style="width:460px;">DM4500 B</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Petridish</td>
			<td style="width:253px;">sym laboratorios</td>
			<td style="width:460px;">90X15</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Scalpel Blade&#160;</td>
			<td style="width:253px;">Fisher scientific</td>
			<td style="width:460px;">53223</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:245px;">Falcon 15mL Conical Centrifuge Tubes</td>
			<td style="width:253px;">Fisher scientific</td>
			<td style="width:460px;">14-959-53A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">22 mL glass tubes</td>
			<td style="width:253px;">Thomas scientific</td>
			<td style="width:460px;">45048-16150</td>
			<td></td>
		</tr>
	</tbody>
</table>

plant promoter analysis: identification and characterization of root nodule specific promoter in the common bean

The upstream sequences of gene coding sequences are termed as promoter sequences. Studying the expression patterns of promoters are very significant in understanding the gene regulation and spatiotemporal expression patterns of target genes. On the other hand, it is also critical to establish promoter evaluation tools and genetic transformation techniques that are fast, efficient, and reproducible. In this study, we investigated the spatiotemporal expression pattern of the rhizobial symbiosis-specific nodule inception (NIN) promoter of Phaseolus vulgaris in the transgenic hairy roots. Using plant genome databases and analysis tools we identified, isolated, and cloned the P. vulgaris NIN promoter in a transcriptional fusion to the chimeric reporter &#946;-glucuronidase (GUS) GUS-enhanced::GFP. Further, this protocol describes a rapid and versatile system of genetic transformation in the P. vulgaris using Agrobacterium rhizogenes induced hairy roots. This system generates &#8805;2 cm hairy roots at 10 to 12 days after transformation. Next, we assessed the spatiotemporal expression of NIN promoter in Rhizobium inoculated hairy roots at periodic intervals of post-inoculation. Our results depicted by GUS activity show that the NIN promoter was active during the process of nodulation. Together, the present protocol demonstrates how to identify, isolate, clone, and characterize a plant promoter in the common bean hairy roots. Moreover, this protocol is easy to use in non-specialized laboratories.

The objective of this study was to assess the spatiotemporal expression pattern of nodule-specific P. vulgaris NIN. To do this, a 700 bp region upstream of the translation initiation codon of the NIN gene was selected and a set of oligos was designed as depicted in Figure 1A. Using a high-fidelity polymerase, the NIN promoter fragment was amplified, isolated (Figure 1B), and cloned into the destination binary ve...

Watch this Scientific Journal Video about Plant Promoter Analysis: Identification and Characterization of Root Nodule Specific Promoter in the Common Bean at JoVE.com

Plant Promoter Analysis: Identification and Characterization of Root Nodule Specific Promoter in the Common Bean

Promoter expression analyses are crucial to improving the understanding of gene regulation and the spatiotemporal expression of target genes. Herein we present a protocol to identify, isolate, and clone a plant promoter. Further, we describe the characterization of the nodule-specific promoter in the common bean hairy roots.

The upstream sequences of gene coding sequences are termed as promoter sequences. Studying the expression patterns of promoters are very significant in ...

Hairy roots are used to obtain transformed roots in Phaseolus with a reporter construct. The resulting transgenic roots are used to examine the expression of the reporter gene. Promoter expression studies are crucial to understand the spatiotemporal expression patterns of genes.Today we are going to demonstrate the methodologies for hairy root induction and to study promoter expression patterns in transgenic hairy roots under root nodule symbiotic conditions in Phaseolus. Estrada-Navarrete and colleagues have previously established Agrobacterium rhizogenes induced hairy root system in Phaseolus. The current method will help accelerate the duration of hairy root induction and thereby improving the versatility of the system.Demonstrating the procedures will be my colleague Manoj-Kumar Arthikala and undergraduate students Alma Leticia and Brenda Mariana from my lab. To begin with, search the NIN gene sequence in Phaseolus vulgaris genome database from Phytozome, and select the required length of sequence upstream to ATG. Design the oligonucleotides following the appropriate promoter sequence analysis.Freshly prepared Phaseolus genomic DNA will serve as the template to PCR amplify the promoter sequence. Prepare the PCR master mix with high-fidelity Taq polymerase and standard PCR components, along with the prior-designed oligonucleotides. Aliquot the master mix into 2 mL PCR tubes, and perform the promoter fragment amplification in a thermocycler and with a suitable program.Separate the PCR product electrophoretically on a 1.2%agarose gel. Visualize the NIN fragment amplified at 700 base pairs under UV transillumination. Excise, elute, and clone the fragment into the Gateway entry vector pENTR/D-TOPO vector following the standard instructions.Transform two microliters of the reaction mix into competent E.coli cells at 42 degrees Celsius for 50 seconds, and plate the transformed E.coli on LB supplemented with 50 milligrams per liter kanamycin. Grow the plated cells at 37 degrees Celsius overnight. Perform a PCR reaction for plasmids isolated from randomly selected E.coli colonies using M13 oligonucleotides.The fragment at 1024 base pairs should indicate positive clones. Perform the LR reaction between the positive entry clone and destination binary vector. Transform two microliters of reaction mix into E.coli, and select the colonies on 100 milligrams per liter of spectinomycin at 37 degrees Celsius.Amplify the plasmids with NIN-specific oligonucleotides. The positive clone should amplify at 700 base pairs. Sequence and verify the correctness of the clone fragment.Mobilize the NIN promoter construct into electrocompetent K599 Agrobacterium rhizogenes cells. And once again, confirm the clone with promoter-specific oligonucleotides. Sulfur sterilize Phaseolus vulgaris seeds and germinate on sterile, wet filter papers for two days in dark at 28 degrees Celsius.Spread 150 microliters of Agrobacterium rhizogenes cells with NIN construct and control vector on LB plates with spectinomycin selection. Grow the culture overnight at 28 degrees Celsius. Decoat Phaseolus seedlings, and scrape out Agrobacterium rhizogenes cells with a bent, 200-microliters tip from the plate.And resuspend into Eppendorf Tube with one mL sterile, distilled water. Collect Agrobacterium rhizogenes cells into a three mL syringe, and place Phaseolus seedlings into previously prepared tube setup. Slightly prick the hypocotyls of germinated seeds with the needle tip, simultaneously injecting the Agrobacterium rhizogenes cells.Care should be taken that the needle do not pass through the hypocotyl. Maintain the injected seedlings in a growth chamber at 28 degrees Celsius with 16 hours light and eight hour dark photoperiod. Callus on the wounded hypocotyls should be visible by five to seven days.After two weeks, remove the primary root by cutting the stem two centimeters below the hairy roots, and transplant them into pots containing sterile vermiculite. Simultaneously, inoculate the plants with one ml Rhizobium tropici to induce nodulation. Make sure to dilute the Rhizobium culture to 6 at OD 600.Maintain the plants in a growth chamber at 28 degrees Celsius, 16 hours light, and eight hours dark photoperiod, and irrigate with B and D solution. To study spatiotemporal expression patterns of NIN promoter, sampling is done at different time points. Take out the plants without damaging the roots, and wash the roots without any specks of vermiculite.Randomly select the roots from NIN and control plants, and proceed to GUS histochemical staining by incubating the samples in GUS assay buffer at 37 degrees Celsius for 16 hours in dark. Observe the GUS-stained roots under stereo and compound microscope. This picture shows the Rhizobium-induced NIN promoter expression in the primary roots.NIN promoter expression could also be seen in Rhizobium-infected root hair cells. Further, the GUS expression can be documented at different stages of root nodule development. No GUS expression was seen in vector control roots.After watching this video, you should have a good understanding of designing your promoter constructs and studying the promoter expression patterns in transgenic hairy roots of Phaseolus. This system could be further extended to study the promoter expression patterns under other symbiotic and pathogen interactions in Phaseolus and also other eudicots.

plant-promoter-analysis-identification-characterization-root-nodule

Research

JoVE Journal

Biology

11.6K Views.  Escuela Nacional de Estudios Superiores Unidad León- Universidad Nacional Autónoma de México (UNAM). Hairy roots are used to obtain transformed roots in Phaseolus with a reporter construct. The resulting transgenic roots are used to examine the expression of the reporter gene. Promoter expression studies are crucial to understand the spatiotemporal expression patterns of genes.Today we are going to demonstrate the methodologies for hairy root induction and to study promoter expression patterns in transgenic hairy roots under root nodule symbiotic conditions in Phaseolus. Estrada-Navar...