This work was supported by the Research Fund of Liaocheng University (318012028) and the Natural Science Foundation of Shandong Province (ZR2020MC034).

1. Plant growth conditions and A. rhizogenes culture
<ol>
	<li>Seed sowing 
	NOTE: Wild soybean seeds were collected in Yanggu County, Liaocheng, China; seeds of S. americanum and pumpkin local variety Yinsu were purchased from a market.
	<ol>
		<li>Collect seeds of wild soybean, S. americanum, and the local variety of pumpkin, sow them in vermiculite at a depth of 1 cm, and thoroughly water them. Plant 20 seeds in 8 cm x 11 cm x 9 cm plastic boxes. Cultivate the plants in a growth chamber at 24 &#177; 2 &#176;C with a 16 h light/8 h dark cycle at approximately 70% relative humidity. 
		NOTE: Coats of wild soybean seeds must be broken before sowing. If the research question focuses on interactions between plants and microorganisms, seeds, vermiculite, plastic boxes, and water must be sterilized before use.</li>
		<li>Activation and culture of A. rhizogenes K599 
		NOTE: The A. rhizogenes K599 strain had one binary vector pRed13052 carrying a red fluorescent reporter gene DsRed2.
		<ol>
			<li>Remove the A. rhizogenes strain K599 from a -80 &#176;C freezer, and activate the bacteria on solid LB medium (with 50 mg/L kanamycin and 50 mg/L streptomycin) at 28 &#176;C for 48 h.</li>
			<li>Pick out a single clone of strain K599 and culture it in 1 mL of liquid antibiotic-containing LB medium for 12 h.</li>
			<li>Evenly spread 500 &#181;L of the bacterial suspension on solid antibiotic-containing LB medium, followed by incubation at 28 &#176;C for 24 h.</li>
		</ol>
		</li>
	</ol>
	</li>
</ol>
2. One-step A. rhizogenes-mediated hairy root transformation method
<ol>
	<li>Hypocotyl incision
	<ol>
		<li>After 7 days (define the sowing of the seeds as day 0), seedling cotyledons have just unfolded (Figure 1A), use a sterilized, sharp scalpel to cut approximately 0.5-1 cm of the hypocotyl (Figure 1B). Discard the primary root and some of the partial hypocotyl. 
		NOTE: Use the scalpel with care.</li>
	</ol>
	</li>
	<li>K599 inoculation
	<ol>
		<li>Coat the hypocotyl incision with K599 bacteria (Figure 1C).</li>
		<li>Plant the seedlings in moist vermiculite (Figure 1D).</li>
		<li>Infect 30 plants of each species via A. rhizogenes-mediated hairy root transformation. Water each plant with 5 mL of resuspended K599 bacterial suspension (OD600 = 0.5-0.6) in a quarter strength (0.25x) Gamborg B-5 basic medium (Figure 1E).</li>
		<li>Cover the pots with a highly transparent plastic bag (Figure 1F) and place them in a growth chamber.</li>
	</ol>
	</li>
</ol>
3. Hairy root production
<ol>
	<li>Grow the plants for ~12 days post inoculation, new hairy roots will be induced and generated at the incision site. After 15 days, the hairy root lengths typically reach 2-5 cm (Figure 2).</li>
	<li>To determine whether the hairy roots produced are transgenic, examine the expression of reporter genes dependent on the transformed vector in K599.
	<ol>
		<li>Detect the expression of the reporter gene DsRed2 using a chemiluminescence imaging system with green excitation light at 540 nm and emission at 600 nm (Figure 2B, Figure 2D, and Figure 2F).</li>
	</ol>
	</li>
</ol>

One-Step Hairy Root Transformation Method for Advancing Root-Related Biology

<ol>
	<li>Chilton, M. 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=Agrobacterium+rhizogenes+inserts+T-DNA+into+the+genome+of+the+host+plant+root+cells.">Agrobacterium rhizogenes inserts T-DNA into the genome of the host plant root cells.</a> Nature. 295, 432-434 (1982).</li><li>Fan, 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=A+fast,+simple,+high+efficient+and+one-step+generation+of+composite+cucumber+plants+with+transgenic+roots+by+Agrobacterium+rhizogenes-mediated+transformation.">A fast, simple, high efficient and one-step generation of composite cucumber plants with transgenic roots by Agrobacterium rhizogenes-mediated transformation.</a> Plant Cell, Tissue and Organ Culture (PCTOC). 141, 207-216 (2020).</li><li>Du, H., 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=Efficient+targeted+mutagenesis+in+soybean+by+TALENs+and+CRISPR/Cas9.">Efficient targeted mutagenesis in soybean by TALENs and CRISPR/Cas9.</a> Journal of Biotechnology. 217, 90-97 (2016).</li><li>Nguyen, D. V., 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+efficient+hairy+root+system+for+validation+of+plant+transformation+vector+and+CRISPR/Cas+construct+activities+in+cucumber+(Cucumis+sativus+L.).">An efficient hairy root system for validation of plant transformation vector and CRISPR/Cas construct activities in cucumber (Cucumis sativus L.).</a> Frontiers in Plant Science. 12, 770062 (2022).</li><li>Liu, 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=AtGCS+promoter-driven+clustered+regularly+interspaced+short+palindromic+repeats/Cas9+highly+efficiently+generates+homozygous/biallelic+mutations+in+the+transformed+roots+by+Agrobacterium+rhizogenes-mediated+transformation.">AtGCS promoter-driven clustered regularly interspaced short palindromic repeats/Cas9 highly efficiently generates homozygous/biallelic mutations in the transformed roots by Agrobacterium rhizogenes-mediated transformation.</a> Frontiers in Plant Science. 13, 952428 (2022).</li><li>Irigoyen, 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=Plant+hairy+roots+enable+high+throughput+identification+of+antimicrobials+against+Candidatus+Liberibacter+spp.">Plant hairy roots enable high throughput identification of antimicrobials against Candidatus Liberibacter spp.</a> Nature Communications. 11 (1), 5802 (2020).</li><li>Plasencia, 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=Eucalyptus+hairy+roots,+a+fast,+efficient+and+versatile+tool+to+explore+function+and+expression+of+genes+involved+in+wood+formation.">Eucalyptus hairy roots, a fast, efficient and versatile tool to explore function and expression of genes involved in wood formation.</a> Plant Biotechnology Journal. 14 (6), 1381-1393 (2016).</li><li>Gutierrez-Valdes, 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=Hairy+root+cultures-a+versatile+tool+with+multiple+applications.">Hairy root cultures-a versatile tool with multiple applications.</a> Frontiers in Plant Science. 11, 33 (2020).</li><li>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=Agrobacterium+rhizogenes+as+a+vector+for+transforming+higher+plants.+Application+in+Lotus+corniculatus+transformation.">Agrobacterium rhizogenes as a vector for transforming higher plants. Application in Lotus corniculatus transformation.</a> Methods in Molecular Biology. 49, 49-61 (1995).</li><li>Kereszt, 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=Agrobacterium+rhizogenes-mediated+transformation+of+soybean+to+study+root+biology.">Agrobacterium rhizogenes-mediated transformation of soybean to study root biology.</a> Nature Protocols. 2 (4), 948-952 (2007).</li><li>Ho-Pl&#225;garo, T., Huertas, R., Tamayo-Navarrete, M. I., Ocampo, J. A., Garc&#237;a-Garrido, 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=An+improved+method+for+Agrobacterium+rhizogenes-mediated+transformation+of+tomato+suitable+for+the+study+of+arbuscular+mycorrhizal+symbiosis.">An improved method for Agrobacterium rhizogenes-mediated transformation of tomato suitable for the study of arbuscular mycorrhizal symbiosis.</a> Plant Methods. 14, 34 (2018).</li><li>Yu, 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=Overexpression+of+phosphatidylserine+synthase+IbPSS1+affords+cellular+Na++homeostasis+and+salt+tolerance+by+activating+plasma+membrane+Na+/H++antiport+activity+in+sweet+potato+roots.">Overexpression of phosphatidylserine synthase IbPSS1 affords cellular Na+ homeostasis and salt tolerance by activating plasma membrane Na+/H+ antiport activity in sweet potato roots.</a> Horticulture Research. 7, 131 (2020).</li><li>Boisson-Dernier, 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=Agrobacterium+rhizogenes-transformed+roots+of+Medicago+truncatula+for+the+study+of+nitrogen-fixing+and+endomycorrhizal+symbiotic+associations.">Agrobacterium rhizogenes-transformed roots of Medicago truncatula for the study of nitrogen-fixing and endomycorrhizal symbiotic associations.</a> Molecular Plant-Microbe Interactions: MPMI. 14 (6), 695-700 (2001).</li><li>Fan, 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=One-step+generation+of+composite+soybean+plants+with+transgenic+roots+by+Agrobacterium+rhizogenes-mediated+transformation.">One-step generation of composite soybean plants with transgenic roots by Agrobacterium rhizogenes-mediated transformation.</a> BMC Plant Biology. 20 (1), 208 (2020).</li><li>Fan, 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=Anthocyanin,+a+novel+and+user-friendly+reporter+for+convenient,+non-destructive,+low+cost,+directly+visual+selection+of+transgenic+hairy+roots+in+the+study+of+rhizobia-legume+symbiosis.">Anthocyanin, a novel and user-friendly reporter for convenient, non-destructive, low cost, directly visual selection of transgenic hairy roots in the study of rhizobia-legume symbiosis.</a> Plant Methods. 16, 94 (2020).</li><li>Wang, X., 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=Application+of+AtMYB75+as+a+reporter+gene+in+the+study+of+symbiosis+between+tomato+and+Funneliformis+mosseae.">Application of AtMYB75 as a reporter gene in the study of symbiosis between tomato and Funneliformis mosseae.</a> Mycorrhiza. 33 (3), 181-185 (2023).</li><li>Wang, X., 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=Development+of+a+set+of+novel+binary+expression+vectors+for+plant+gene+function+analysis+and+genetic+transformation.">Development of a set of novel binary expression vectors for plant gene function analysis and genetic transformation.</a> Frontiers in Plant Science. 13, 1104905 (2023).</li><li>Li, Q. 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=Phytochrome+B+inhibits+darkness-induced+hypocotyl+adventitious+root+formation+by+stabilizing+IAA14+and+suppressing+ARF7+and+ARF19.">Phytochrome B inhibits darkness-induced hypocotyl adventitious root formation by stabilizing IAA14 and suppressing ARF7 and ARF19.</a> The Plant Journal: For Cell and Molecular Biology. 105 (6), 1689-1702 (2021).</li></ol>

The authors have no conflicts of interest to declare.

The one-step A. rhizogenes-mediated&#160;hairy root method is a simpler and more efficient method for producing composite plants than the hypocotyl-injection method. The one-step ARM method significantly improves the efficiency of hairy root transformation, shortens the time to produce hairy roots, increases the number of hairy roots, and reduces the amount of work involved. The improved transformation protocol is optimal for studies on symbioses between leguminous plants and rhizobia and between plants and arbu...

Agrobacterium rhizogenes is a gram-negative soil bacterium from the family Rhizobiaceae. A. rhizogenes can infect almost all dicotyledons, a few monocotyledons, and individual gymnosperms through wounds, producing hairy roots in infected plants. The bacterium carries the Ri (root-inducing) plasmid, and the T-DNA of the Ri plasmid carries the opine synthesis gene and rol genes (root locus genes). After the T-DNA of the Ri plasmid enters a plant cell and is integrated into a host chromosome, the expression of the rol genes induces production of hairy roots1. A plant binary expression vector carrying a target gene is transformed into A. rhizogenes, and the transformed A. rhizogenes is used to infect a plant. Transgenic roots can be induced in infected plants, producing composite plants containing transgenic roots and nontransgenic stems and buds. Generally, a composite plant can be obtained within 14-20 days. A. rhizogenes-mediated hairy root transformation is generally not limited by genotype in dicotyledonous plants2. The hairy roots produced by A. rhizogenes-infected plants are characterized by a fast growth rate, stable inheritance, and easy operation. Hairy root transformation mediated by A. rhizogenes is currently widely used to study root-related biology. Furthermore, the transformation of hairy roots can also be used to validate and optimize the target-editing efficiency of the CRISPR/Cas9 system3,4,5 and protein subcellular localization. Therefore, hairy root transformation is an important tool in research on plant gene function, metabolic engineering, and interactions between roots and rhizosphere microorganisms6,7,8.
Composite plants containing transgenic roots obtained through hairy root transformation have been widely produced in dicotyledonous plants, especially in legumes. The traditional method of injecting the hypocotyl with A. rhizogenes has been used to produce composite Lotus corniculatus9, soybeans10, tomato11, sweet potatoes12,&#160;and many other plants5,8. The hypocotyl-injection method is inefficient and is likely to cause the death of young or tiny hypocotyl plants. Therefore, the method was improved by cutting off the embryonic roots, coating the seedling incision with A. rhizogenes, and then placing the hypocotyl on sterile culture medium for rooting cultivation13. However, those steps are performed in a sterile environment, and the operation steps are relatively cumbersome. In particular, the resulting composite plants need to be transplanted, which increases the amount of work. In previous work, one-step A. rhizogenes-mediated (ARM) hairy root transformation was established in cucumber, soybean, Lotus japonicus, Medicago truncatula,&#160;and tomato2,14,15,16,17. The primary root and partial hypocotyl were removed, the incision site of the remaining hypocotyl was coated with transformed A. rhizogenes, and the seedling was then planted into moist sterile vermiculite. After 12 days of cultivation, hairy roots were produced at the incision site. The one-step ARM method is highly efficient and requires less time to produce hairy roots. Transplanting after forming hairy roots is also not necessary. Because microbial contamination can be avoided without transplantation, the one-step ARM method can be particularly useful when studying interactions between plants and microorganisms, such as symbiotic nitrogen fixation between leguminous plants and Rhizobia, and symbioses between plants and arbuscular mycorrhizal fungi. In this paper, a detailed one-step A. rhizogenes-mediated&#160;hairy root transformation protocol is provided with examples of composite plants produced in wild soybean, Solanum americanum, and pumpkin. With the protocol, researchers can smoothly perform the one-step ARM transformation.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>kanamycin</td>
			<td>Sangon Biotech (Shanghai) Co., Ltd.</td>
			<td>A506636</td>
			<td></td>
		</tr>
		<tr>
			<td>LB medium</td>
			<td>Sangon Biotech (Shanghai) Co., Ltd.</td>
			<td>B540113</td>
			<td></td>
		</tr>
		<tr>
			<td>plastic box</td>
			<td>LiaoSu</td>
			<td></td>
			<td>8 cm x 11 cm x 9 cm</td>
		</tr>
		<tr>
			<td>pumpkin</td>
			<td></td>
			<td></td>
			<td>local variety Yinsu</td>
		</tr>
		<tr>
			<td>streptomycin</td>
			<td>Sangon Biotech (Shanghai) Co., Ltd.</td>
			<td>A610494&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>Tanon-5200Multi machine</td>
			<td>Tanon Co., Ltd., China</td>
			<td>5200Multi</td>
			<td>chemiluminescence imaging system</td>
		</tr>
		<tr>
			<td>tomato</td>
			<td></td>
			<td></td>
			<td>local variety Zhongshu4</td>
		</tr>
		<tr>
			<td>wild soybean</td>
			<td></td>
			<td></td>
			<td>collected in Yanggu County, Liaocheng, China</td>
		</tr>
	</tbody>
</table>

an efficient and reproducible method for producing composite plants by agrobacterium rhizogenes-based hairy root transformation

Producing composite plants with transgenic roots and nontransgenic stems and buds using Agrobacterium rhizogenes-mediated hairy root transformation is a powerful tool to study root-related biology. Hairy root transformation is established in a wide range of dicotyledons and in several monocotyledon species and is almost independent of the genotype. The traditional method of hypocotyl injection with A. rhizogenes to obtain composite plants is inefficient, time-consuming, laborious, and frequently causes the death of tender and tiny hypocotyl plants. A highly efficient, one-step hairy root transformation mediated by A. rhizogenes was established previously, which eliminates the need for transplanting after producing hairy roots. In this study, a partial hypocotyl and primary root were removed, the hypocotyl incision site was coated with A. rhizogenes, and&#160;then hypocotyls were planted in sterile vermiculite. After 12 days of cultivation, the hypocotyl incision expanded and new hairy roots were induced. This article provides the detailed protocol of a one-step transformation method mediated by A. rhizogenes, with its effectiveness demonstrated by producing composite plants of wild soybean, Solanum americanum, and pumpkin.

Highly efficient one-step A. rhizogenes-mediated&#160;hairy root transformation 
Hairy roots were produced at the hypocotyl incision site 12 days after inoculation with engineered K599. Transgenic hairy roots were determined based on the expression of the reporter gene contained in the binary vector. Transgenic roots transformed with the reporter gene DsRed2 of composite wild soybean, S. americanum, and pumpkin were observed under natural (Figure 2A</s...

Watch this Scientific Journal Video about Streamlining Composite Plant Production via Agrobacterium rhizogenes-Mediated Hairy Root Transformation at JoVE.com

Author Spotlight: Streamlining Composite Plant Production via Agrobacterium rhizogenes-Mediated Hairy Root Transformation 

Here, we provide the detailed protocol of a one-step transformation method mediated by Agrobacterium tumefaciens to produce composite plants.

An Efficient and Reproducible Method for Producing Composite Plants by Agrobacterium rhizogenes-Based Hairy Root Transformation

Producing composite plants with transgenic roots and nontransgenic stems and buds using Agrobacterium rhizogenes-mediated hairy root transformation is a ...

an-efficient-reproducible-method-for-producing-composite-plants

Research

JoVE Journal

Biology

1.9K Views.  Liaocheng University. Here, we provide the detailed protocol of a one-step transformation method mediated by Agrobacterium tumefaciens to produce composite plants.

Video: Author Spotlight: Streamlining Composite Plant Production via Agrobacterium rhizogenes-Mediated Hairy Root Transformation 

Efficient Polyethylene Glycol (PEG) Mediated Transformation of the Moss Physcomitrella patens

A simple and efficient method to transform Physcomitrella pantens protoplasts is described. This method is adapted from protocols for Physocmitrella protonemal protoplast and Arabidopsis mesophyll protoplast transformation1. Due to its capacity to undergo efficient mitotic homologous recombination, Physcomitrella patens has emerged as an important model system in recent years2. This capacity allows high frequencies of gene targeting3-9, which is not seen in other model plants such as Arabidopsis. To take full advantage of this system, we need an effective and easy method to deliver DNA into moss cells. The most common ways to transform this moss are particle bombardment10 and PEG-mediated DNA uptake11. Although particle bombardment can produce a high transformation efficiency12, gene guns are not readily available to many laboratories and the protocol is difficult to standardize. On the other hand, PEG mediated transformation does not require specialized equipments, and can be performed in any laboratory with a sterile hood. Here, we show a simple and highly efficient method for transformation of moss protoplasts. This method can generate more than 120 transient transformants per microgram of DNA, which is an improvement from the most efficient protocol previously reported13. Because of its simplicity, efficiency, and reproducibility, this method can be applied to projects requiring large number of transformants as well as for routine transformation.

Efficient Polyethylene Glycol PEG Mediated Transformation of the Moss Physcomitrella patens

A simple and efficient method to transform Physcomitrella pantens protoplasts is described. This method is adapted from protocols for Physocmitrella protonemal protoplast and Arabidopsis mesophyll protoplast transformation1.

A simple and efficient method to transform Physcomitrella pantens protoplasts is described. This method is adapted from protocols for Physocmitrella ...

Generation of Composite Plants in Medicago truncatula used for Nodulation Assays

Similar to Agrobacterium tumerfaciens, Agrobacterium rhizogenes can transfer foreign DNAs into plant cells based on the autonomous root-inducing (Ri) plasmid. A. rhizogenes can cause hairy root formation on plant tissues and form composite plants after transformation. On these composite plants, some of the regenerated roots are transgenic, carrying the wild type T-DNA and the engineered binary vector; while the shoots are still non-transgenic, serving to provide energy and growth support. These hairy root composite plants will not produce transgenic seeds, but there are a number of important features that make these composite plants very useful in plant research. First, with a broad host range,A. rhizogenes can transform many plant species, especially dicots, allowing genetic engineering in a variety of species. Second, A. rhizogenes infect tissues and explants directly; no tissue cultures prior to transformation is necessary to obtain composite plants, making them ideal for transforming recalcitrant plant species. Moreover, transgenic root tissues can be generated in a matter of weeks. For Medicago truncatula, we can obtain transgenic roots in as short as three weeks, faster than normal floral dip Arabidopsis transformation. Overall, the hairy root composite plant technology is a versatile and useful tool to study gene functions and root related-phenotypes. Here we demonstrate how hairy root composite plants can be used to study plant-rhizobium interactions and nodulation in the difficult-to-transform species M. truncatula.

Generation of Composite Plants in Medicago truncatula used for Nodulation Assays

We demonstrate how hairy root composite plants can be used to study plant-rhizobium interactions and nodulation in the difficult-to-transform species Medicago truncatula.

Similar to Agrobacterium tumerfaciens, Agrobacterium rhizogenes can transfer foreign DNAs into plant cells based on the autonomous root-inducing (Ri) ...

Efficient Agroinfiltration of Plants for High-level Transient Expression of Recombinant Proteins

Mammalian cell culture is the major platform for commercial production of human vaccines and therapeutic proteins. However, it cannot meet the increasing worldwide demand for pharmaceuticals due to its limited scalability and high cost. Plants have shown to be one of the most promising alternative pharmaceutical production platforms that are robust, scalable, low-cost and safe. The recent development of virus-based vectors has allowed rapid and high-level transient expression of recombinant proteins in plants. To further optimize the utility of the transient expression system, we demonstrate a simple, efficient and scalable methodology to introduce target-gene containing Agrobacterium into plant tissue in this study. Our results indicate that agroinfiltration with both syringe and vacuum methods have resulted in the efficient introduction of Agrobacterium into leaves and robust production of two fluorescent proteins; GFP and DsRed. Furthermore, we demonstrate the unique advantages offered by both methods. Syringe infiltration is simple and does not need expensive equipment. It also allows the flexibility to either infiltrate the entire leave with one target gene, or to introduce genes of multiple targets on one leaf. Thus, it can be used for laboratory scale expression of recombinant proteins as well as for comparing different proteins or vectors for yield or expression kinetics. The simplicity of syringe infiltration also suggests its utility in high school and college education for the subject of biotechnology. In contrast, vacuum infiltration is more robust and can be scaled-up for commercial manufacture of pharmaceutical proteins. It also offers the advantage of being able to agroinfiltrate plant species that are not amenable for syringe infiltration such as lettuce and Arabidopsis. Overall, the combination of syringe and vacuum agroinfiltration provides researchers and educators a simple, efficient, and robust methodology for transient protein expression. It will greatly facilitate the development of pharmaceutical proteins and promote science education.

Plants offer a novel system for the production of pharmaceutical proteins on a commercial scale that is more scalable, cost-efficient and safe than current expression paradigms. In this study, we report a simple and convenient, yet scalable approach to introduce target-gene containing Agrobacterium tumefaciens into plants for protein transient expression.

Mammalian cell culture is the major platform for commercial production of human vaccines and therapeutic proteins. However, it cannot meet the increasing ...

An In Vitro Model for Studying Cellular Transformation by Kaposi Sarcoma Herpesvirus

Kaposi sarcoma (KS) is an unusual tumor composed of proliferating spindle cells that is initiated by infection of endothelial cells (EC) with KSHV, and develops most often in the setting of immunosuppression. Despite decades of research, optimal treatment of KS remains poorly defined and clinical outcomes are especially unfavorable in resource-limited settings. KS lesions are driven by pathological angiogenesis, chronic inflammation, and oncogenesis, and various in vitro cell culture models have been developed to study these processes. KS arises from KSHV-infected cells of endothelial origin, so EC-lineage cells provide the most appropriate in vitro surrogates of the spindle cell precursor. However, because EC have a limited in vitro lifespan, and as the oncogenic mechanisms employed by KSHV are less efficient than those of other tumorigenic viruses, it has been difficult to assess the processes of transformation in primary or telomerase-immortalized EC. Therefore, a novel EC-based culture model was developed that readily supports transformation following infection with KSHV. Ectopic expression of the E6 and E7 genes of human papillomavirus type 16 allows for extended culture of age- and passage-matched mock- and KSHV-infected EC and supports the development of a truly transformed (i.e., tumorigenic) phenotype in infected cell cultures. This tractable and highly reproducible model of KS has facilitated the discovery of several essential signaling pathways with high potential for translation into clinical settings.

An In Vitro Model for Studying Cellular Transformation by Kaposi Sarcoma Herpesvirus

Kaposi sarcoma (KS) is a tumor induced by infection with the oncogenic virus human herpesvirus-8/KS herpesvirus (HHV-8/KSHV). The endothelial cell culture model described here is uniquely suited for studying the mechanisms by which KSHV transforms host cells.

Kaposi sarcoma (KS) is an unusual tumor composed of proliferating spindle cells that is initiated by infection of endothelial cells (EC) with KSHV, and ...

An Efficient and Flexible Cell Aggregation Method for 3D Spheroid Production

Monolayer cell culture does not adequately model the in vivo behavior of tissues, which involves complex cell-cell and cell-matrix interactions. Three-dimensional (3D) cell culture techniques are a recent innovation developed to address the shortcomings of adherent cell culture. While several techniques for generating tissue analogues in vitro have been developed, these methods are frequently complex, expensive to establish, require specialized equipment, and are generally limited by compatibility with only certain cell types. Here, we describe a rapid and flexible protocol for aggregating cells into multicellular 3D spheroids of consistent size that is compatible with growth of a variety of tumor and normal cell lines. We utilize varying concentrations of serum and methyl cellulose (MC) to promote anchorage-independent spheroid generation and prevent the formation of cell monolayers in a highly reproducible manner. Optimal conditions for individual cell lines can be achieved by adjusting MC or serum concentrations in the spheroid formation medium. The 3D spheroids generated can be collected for use in a wide range of applications, including cell signaling or gene expression studies, candidate drug screening, or in the study of cellular processes such as tumor cell invasion and migration. The protocol is also readily adapted to generate clonal spheroids from single cells, and can be adapted to assess anchorage-independent growth and anoikis-resistance. Overall, our protocol provides an easily modifiable method for generating and utilizing 3D cell spheroids in order to recapitulate the 3D microenvironment of tissues and model the in vivo growth of normal and tumor cells.

Here, we describe a rapid and flexible protocol for the formation of 3D cell spheroids through cell aggregation. This is easily adapted to multiple cell types and is suitable for use in a variety of applications including cell migration, invasion, or anoikis assays, and for imaging and quantifying cell-matrix interactions.

Monolayer cell culture does not adequately model the in vivo behavior of tissues, which involves complex cell-cell and cell-matrix interactions. ...

An Efficient In Vitro Transposition Method by a Transcriptionally Regulated Sleeping Beauty System Packaged into an Integration Defective Lentiviral Vector

The Sleeping Beauty (SB) transposon is a non-viral integrating system with proven efficacy for gene transfer and functional genomics. To optimize the SB transposon machinery, a transcriptionally regulated hyperactive transposase (SB100X) and T2-based transposon are employed. Typically, the transposase and transposon are provided transiently by plasmid transfection and SB100X expression is driven by a constitutive promoter. Here, we describe an efficient method to deliver the SB components to human cells that are resistant to several physical and chemical transfection methods, to control SB100X expression and stably integrate a gene of interest (GOI) through a &#34;cut and paste&#34; SB mechanism. The expression of hyperactive transposase is tightly controlled by the Tet-ON system, widely used to control gene expression since 1992. The gene of interest is flanked by inverted repeats (IR) of the T2 transposon. Both SB components are packaged in integration defective lentiviral vectors transiently produced in HEK293T cells. Human cells, either cell lines or primary cells from human tissue, are in vitro transiently transduced with viral vectors. Upon addition of doxycycline (dox, tetracycline analog) into the culture medium, a fine-tuning of transposase expression is measured and results in a long-lasting integration of the gene of interest in the genome of the treated cells. This method is efficient and applicable to the cell line (e.g., HeLa cells) and primary cells (e.g., human primary keratinocytes), and thus represents a valuable tool for genetic engineering and therapeutic gene transfer.

An Efficient In Vitro Transposition Method by a Transcriptionally Regulated Sleeping Beauty System Packaged into an Integration Defective Lentiviral Vector

This protocol describes a method to achieve stable integration of a gene of interest into the human genome by the transcriptionally regulated Sleeping Beauty system. Preparation of the integration of defective lentiviral vectors, the in vitro transduction of human cells, and the molecular assay on transduced cells are reported.

The Sleeping Beauty (SB) transposon is a non-viral integrating system with proven efficacy for gene transfer and functional genomics. To optimize the SB ...

Agrobacterium-Mediated Immature Embryo Transformation of Recalcitrant Maize Inbred Lines Using Morphogenic Genes

Demonstrated here is a detailed protocol for Agrobacterium-mediated genetic transformation of maize inbred lines using morphogenic genes Baby boom (Bbm) and Wuschel2 (Wus2). Bbm is regulated by the maize phospholipid transferase gene (Pltp) promoter, and Wus2 is under the control of a maize auxin-inducible (Axig1) promoter. An Agrobacterium strain carrying these morphogenic genes on transfer DNA (T-DNA) and extra copies of Agrobacterium virulence (vir) genes are used to infect maize immature embryo explants. Somatic embryos form on the scutella of infected embryos and can be selected by herbicide resistance and germinated into plants. A heat-activated cre/loxP recombination system built into the DNA construct allows for removal of morphogenic genes from the maize genome during an early stage of the transformation process. Transformation frequencies of approximately 14%, 4%, and 4% (numbers of independent transgenic events per 100 infected embryos) can be achieved for W22, B73, and Mo17, respectively, using this protocol.

Agrobacterium-Mediated Immature Embryo Transformation of Recalcitrant Maize Inbred Lines Using Morphogenic Genes

Plant morphogenic genes can be used to improve genetic transformation of recalcitrant genotypes. Described here is an Agrobacterium-mediated genetic transformation (QuickCorn) protocol for three important public maize inbred lines.

Demonstrated here is a detailed protocol for Agrobacterium-mediated genetic transformation of maize inbred lines using morphogenic genes Baby boom (Bbm) ...

Agrobacterium-Mediated Genetic Transformation, Transgenic Production, and Its Application for the Study of Male Reproductive Development in Rice

Male sterility is an important agronomic trait for hybrid seed production that is usually characterized by functional defects in male reproductive organs/gametes. Recent advances in CRISPR-Cas9 genome editing technology allow for high editing efficacy and timesaving knockout mutations of endogenous candidate genes at specific sites. Additionally, Agrobacterium-mediated genetic transformation of rice is also a key method for gene modification, which has been widely adopted by many public and private laboratories. In this study, we applied CRISPR-Cas9 genome editing tools and successfully generated three male sterile mutant lines by targeted genome editing of OsABCG15 in a japonica cultivar. We used a modified Agrobacterium-mediated rice transformation method that could provide excellent means of genetic emasculation for hybrid seed production in rice. Transgenic plants can be obtained within 2&#8211;3 months and homozygous transformants were screened by genotyping using PCR amplification and Sanger sequencing. Basic phenotypic characterization of the male sterile homozygous line was performed by microscopic observation of the rice male reproductive organs, pollen viability analysis by iodine potassium iodide (I2-KI) staining semi-thin cross-sectioning of developing anthers.

Agrobacterium-Mediated Genetic Transformation, Transgenic Production, and Its Application for the Study of Male Reproductive Development in Rice

This work describes the use of CRISPR-Cas9 genome editing technology to knockout endogenous gene OsABCG15 followed by a modified Agrobacterium-mediated transformation protocol to produce a stable male-sterile line in rice.

Male sterility is an important agronomic trait for hybrid seed production that is usually characterized by functional defects in male reproductive ...

An Easy and Flexible Inoculation Method for Accurately Assessing Powdery Mildew-Infection Phenotypes of Arabidopsis and Other Plants

Reducing crop losses due to fungal diseases requires improved understanding of the mechanisms governing plant immunity and fungal pathogenesis, which in turn requires accurate determination of disease phenotypes of plants upon infection with a particular fungal pathogen. However, accurate disease phenotyping with unculturable biotrophic fungal pathogens such as powdery mildew is not easy to achieve and can be a rate-limiting step of a research project. Here, we have developed a safe, efficient, and easy-to-operate disease phenotyping system using the Arabidopsis-powdery mildew interaction as an example. This system mainly consists of three components: (i) a wooden inoculation box fitted with a removable lid mounted with a stainless steel or nylon mesh of ~50 &#181;m pores for inoculating a flat of plants with fungal spores, (ii) a transparent plastic chamber with a small front opening for minimizing spore escape while conducting inoculation inside, and (iii) a spore-dislodging and distribution method for even and effective inoculation. The protocols described here include the steps and parameters for making the inoculation box and the plastic chamber at a low cost, and a video demonstration of how to use the system to enable even inoculation with powdery mildew spores, thereby improving accuracy and reproducibility of disease phenotyping.

We present a protocol for constructing a simple spore-distribution system consisting of an inoculation box with a ~50 &#181;m mesh and a transparent plastic chamber. This can be used to evenly inoculate plants with powdery mildew spores, thereby enabling accurate and reproducible assessment of disease phenotypes of plants under study.

Reducing crop losses due to fungal diseases requires improved understanding of the mechanisms governing plant immunity and fungal pathogenesis, which in ...

A Simple Protocol for Mapping the Plant Root System Architecture Traits

Comprehensive knowledge of plant root system architecture (RSA) development is critical for improving nutrient use efficiency and increasing crop cultivar tolerance to environmental challenges. An experimental protocol is presented for setting up the hydroponic system, plantlet growth, RSA spreading, and imaging. The approach used a magenta box-based hydroponic system containing polypropylene mesh supported by polycarbonate wedges. Experimental settings are exemplified by assessing the RSA of the plantlets under varying nutrient (phosphate [Pi]) supply. The system was established to examine the RSA of Arabidopsis, but it is readily adaptable to study other plants like Medicago sativa (Alfalfa). Arabidopsis thaliana (Col-0) plantlets are used in this investigation as an example to understand the plant RSA. Seeds are surface sterilized by treating ethanol and diluted commercial bleach, and kept at 4 &#176;C for stratification. The seeds are germinated and grown on a liquid half-MS medium on a polypropylene mesh supported by polycarbonate wedges. The plantlets are grown under standard growth conditions for the desired number days, gently picked out from the mesh, and submersed in water-containing agar plates. Each root system of the plantlets is spread gently on the water-filled plate with the help of a round art brush. These Petri plates are photographed or scanned at high resolution to document the RSA traits. The root traits, such as primary root, lateral roots, and branching zone, are measured using the freely available ImageJ software. This study provides techniques for measuring plant root characteristics in controlled environmental settings. We discuss how to (1) grow the plantlets, and collect and spread root samples, (2) obtain pictures of spread RSA samples, (3) capture the images, and (4) use image analysis software to quantify root attributes. The advantage of the present method is the versatile, easy, and efficient measurement of the RSA traits.

We use simple laboratory tools to examine the root system architecture (RSA) of Arabidopsis and Medicago. The plantlets are grown hydroponically over mesh and spread using an art brush to reveal the RSA. Images are taken using scanning or a high-resolution camera, then analyzed with ImageJ to map traits.

Comprehensive knowledge of plant root system architecture (RSA) development is critical for improving nutrient use efficiency and increasing crop cultivar ...

An Efficient and Reproducible Method for Producing Composite Plants by Agrobacterium rhizogenes-Based Hairy Root Transformation

Podsumowanie

Przeglądaj więcej filmów

Rozdziały w tym wideo

Efficient Polyethylene Glycol (PEG) Mediated Transformation of the Moss Physcomitrella patens

Generation of Composite Plants in Medicago truncatula used for Nodulation Assays

Efficient Agroinfiltration of Plants for High-level Transient Expression of Recombinant Proteins

An In Vitro Model for Studying Cellular Transformation by Kaposi Sarcoma Herpesvirus

An Efficient and Flexible Cell Aggregation Method for 3D Spheroid Production

An Efficient In Vitro Transposition Method by a Transcriptionally Regulated Sleeping Beauty System Packaged into an Integration Defective Lentiviral Vector

Agrobacterium-Mediated Immature Embryo Transformation of Recalcitrant Maize Inbred Lines Using Morphogenic Genes

Agrobacterium-Mediated Genetic Transformation, Transgenic Production, and Its Application for the Study of Male Reproductive Development in Rice

An Easy and Flexible Inoculation Method for Accurately Assessing Powdery Mildew-Infection Phenotypes of Arabidopsis and Other Plants

A Simple Protocol for Mapping the Plant Root System Architecture Traits