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Liu PY, Li G, Lin CB, Wu JJ, Jiang S, Huang FH, Wan X. Modulating DHA-Producing Schizochytrium sp. toward Astaxanthin Biosynthesis via a Seamless Genome Editing System. ACS Synth Biol 2022; 11:4171-4183. [PMID: 36454215 DOI: 10.1021/acssynbio.2c00490] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Schizochytrium sp. is commercially used for the production of docosahexaenoic acid (DHA). Some strains of Schizochytrium sp. are also known to produce low amounts of carotenoids, including astaxanthin and β-carotene. In order to enhance the production of astaxanthin in Schizochytrium sp., we established a seamless genome editing system with a dual selection marker for rapid screening of positive transformants. By using this system, we strengthened the endogenous mevalonate pathway, enhanced the supply of geranylgeranyl diphosphate and β-carotene, upregulated endogenous β-carotene hydroxylase, and introduced the algal astaxanthin pathway. The highest astaxanthin production in the engineered Schizochytrium sp. was achieved at 8.1 mg/L (307.1 μg/g dry cell weight) under shake-flask conditions, which was 2.6-fold higher than that in the start strain. Meanwhile, the percentage of DHA to total fatty acids was not obviously affected. We then eliminated the dual selection marker by using the Cre-loxP recombination system, and the engineered strain was ready for iterative editing. The developed system could be applied to seamlessly engineer DHA-producing Schizochytrium sp. toward astaxanthin and other value-added terpenoids, which broadens the application of this strain.
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Affiliation(s)
- Peng-Yang Liu
- Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Gang Li
- Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Chu-Bin Lin
- Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Jun-Jie Wu
- Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Shan Jiang
- Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Feng-Hong Huang
- Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, China.,Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430062, China.,Key Laboratory of Oilseeds processing, Ministry of Agriculture, Wuhan 430062, China
| | - Xia Wan
- Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, China.,Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430062, China.,Key Laboratory of Oilseeds processing, Ministry of Agriculture, Wuhan 430062, China
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In vitro functional genetic modification of canine adenovirus type 2 genome by CRISPR/Cas9. J Transl Med 2021; 101:1627-1636. [PMID: 34417549 DOI: 10.1038/s41374-021-00654-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 07/30/2021] [Accepted: 08/02/2021] [Indexed: 11/09/2022] Open
Abstract
Genetically modified oncolytic adenoviruses have been proposed as a vehicle for cancer therapy. However, several concerns, such as toxicity to normal cells and organs, lack of suitable cell surface receptors to allow viral entry to the desired cell type(s), and activation of both innate and adaptive immune systems in patients, restrict the successful clinical application of adenoviral-mediated cancer gene therapy. Successful virotherapy will require efficient transductional and transcriptional targeting to enhance therapeutic efficacy by ensuring targeted adenoviral infection, replication, and/or therapeutic transgene expression. Targeted modification of viral components, such as viral capsid, fiber knob, and the insertion of transgenes for expression, are prerequisites for the necessary transductional and transcriptional targeting of adenovirus. However, the conventional approach to modify the adenoviral genome is complex, time consuming, and expensive. It is dependent on the presence of unique restriction enzyme sites that may or may not be present in the target location. Clustered regularly interspaced short palindromic repeat (CRISPR) along with the RNA-guided nuclease Cas9 (CRISPR/Cas9) is one of the most powerful tools that has been adopted for precise genome editing in a variety of cells and organisms. However, the ability of the CRISPR/Cas9 system to precisely and efficiently make genetic modification, as well as introduce gene replacements, in adenoviral genomes, remains essentially unknown. Herein the ability of in vitro CRISPR/CAS9-mediated editing of the canine adenovirus type 2 (CAV2) genome to promote targeted modification of the viral genome was assessed. To demonstrate the feasibility of this goal, CRISPR/Cas9 has been used to successfully insert the RFP (red fluorescent protein) reporter construct into the CAV2 genome. Initial results demonstrated high efficiency and accuracy for in vitro CRISPR-mediated editing of the large CAV2 genome. Furthermore, this application was expanded, using multiple guide RNAs, to conduct gene replacement in the CAV2 genome by substituting a portion of the E3 gene with a construct designed to express a single chain antibody to canine PD-1. Thus, this work provides a significantly improved and efficient method for targeted editing of adenoviruses to generate altered and potentially therapeutic viral genomes in the shortest possible time.
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Shen Y, Ji R, Chai R, Yuan N, Zhang J, Jing Y, Yang M, Zhang L, Hong Y, Lin J, Zhu C. A novel fluorescence immunochromatographic assay strip for the diagnosis of schistosomiasis japonica. Parasit Vectors 2021; 14:8. [PMID: 33407752 PMCID: PMC7788720 DOI: 10.1186/s13071-020-04511-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 12/01/2020] [Indexed: 11/18/2022] Open
Abstract
Background Schistosomiasis japonica is a severe zoonosis. Domestic animals are the primary source of infection and play an important role in disease transmission. Surveillance and diagnosis play key roles in schistosomiasis control; however, current techniques for the surveillance and diagnosis of the disease have limitations. In this study, we developed a novel fluorescence immunochromatographic assay (FICA) strip to detect anti-Schistosoma japonicum antibodies in host serum. Methods A FICA strip was developed for the diagnosis of Schistosoma japonicum in domestic animals. Streptococcus protein G (SPG) and soluble egg antigen (SEA) were transferred onto a nitrocellulose (NC) membrane to form the control line (C) and the test line (T), respectively. With fluorescence activity as well as binding activity to multispecies IgG, the recombinant protein rSPG-RFP was expressed and employed as an antibody indicator in the FICA strips. Results The dual gene fusion plasmid was verified by PCR and restriction enzyme digestion. The expressed recombinant protein was 39.72 kDa in size, which was consistent with the predicted molecular weight. The western blot results showed binding activity between rSPG-RFP and IgGs from different hosts. Fluorescence microscopy also showed the fluorescence activity of the protein present. The affinity constant (Ka) values of rSPG-RFP with rabbit, donkey, mouse and goat IgG were 1.9 × 105, 4.1 × 105, 1.7 × 105 and 5.4 × 105, respectively. Moreover, based on the recombinant protein, the test strip for detecting S. japonicum in buffaloes could distinguish positive from negative serum. The lower limit of detection of the FICA strip was 1:10,000. Compared with ELISA, the FICA strips exhibited similar results in the diagnosis of infection in clinical bovine serum samples, with a kappa value of 0.9660 and P < 0.01. The cross-reactivities of the FICA strips with Haemonchus contortus and Schistosoma turkestanicum (30.15% and 91.66%, respectively) were higher than those of ELISA (26.98% and 87.5%, respectively). Conclusions Based on the rSPG-RFP protein that we developed, strip detection can be completed within 15 min. Heightened sensitivity allows the strip to accurately identify schistosome antibodies in serum. In conclusion, this method is convenient, feasible, rapid and effective for detecting S. japonicum.![]()
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Affiliation(s)
- Yuanxi Shen
- Key Laboratory of Animal Parasitology, Ministry of Agriculture of China, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Rongyi Ji
- Key Laboratory of Animal Parasitology, Ministry of Agriculture of China, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Rui Chai
- Key Laboratory of Animal Parasitology, Ministry of Agriculture of China, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Nana Yuan
- Key Laboratory of Animal Parasitology, Ministry of Agriculture of China, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Jiyue Zhang
- Key Laboratory of Animal Parasitology, Ministry of Agriculture of China, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Yi Jing
- Key Laboratory of Animal Parasitology, Ministry of Agriculture of China, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Man Yang
- Key Laboratory of Animal Parasitology, Ministry of Agriculture of China, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Lanqi Zhang
- Key Laboratory of Animal Parasitology, Ministry of Agriculture of China, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China.,University of Reading, Whiteknights, Reading, Berkshire, RG26UA, England
| | - Yang Hong
- Key Laboratory of Animal Parasitology, Ministry of Agriculture of China, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Jiaojiao Lin
- Key Laboratory of Animal Parasitology, Ministry of Agriculture of China, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Chuangang Zhu
- Key Laboratory of Animal Parasitology, Ministry of Agriculture of China, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China.
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4
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Fan Y, Wang X, Li H, Liu S, Jin L, Lyu Y, Shi M, Liu S, Yang X, Lyu S. 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. PLANT METHODS 2020; 16:94. [PMID: 32647533 PMCID: PMC7339386 DOI: 10.1186/s13007-020-00638-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 07/03/2020] [Indexed: 05/05/2023]
Abstract
BACKGROUND Agrobacterium rhizogenes-mediated hairy root transformation provides a powerful tool for investigating the functions of plant genes involved in rhizobia-legume symbiosis. However, in the traditional identification methods of transgenic hairy roots based on reporter genes, an expensive chemical substrate or equipment is required. RESULTS Here, we report a novel, low cost, and robust reporter for convenient, non-destructive, and directly visual selection of transgenic hairy roots by naked eye, which can be used in the study of rhizobia-legume symbiosis. The reporter gene AtMyb75 in Arabidopsis, encoding an R2R3 type MYB transcription factor, was ectopically expressed in hairy roots-mediated by A. rhizogenes, which induced purple/red colored anthocyanin accumulation in crop species like soybean (Glycine max (L.) Merr.) and two model legume species, Lotus japonicas and Medicago truncatula. Transgenic hairy roots of legumes containing anthocyanin can establish effective symbiosis with rhizobia. We also demonstrated the reliability of AtMyb75 as a reporter gene by CRISPR/Cas9-targeted mutagenesis of the soybean resistance to nodulation Rfg1 gene in the soybean PI377578 (Nod-) inoculated with Sinorhizobium fredii USDA193. Without exception, mature nitrogen-fixation nodules, were formed on purple transgenic hairy roots containing anthocyanin. CONCLUSIONS Anthocyanin is a reliable, user-friendly, convenient, non-destructive, low cost, directly visual reporter for studying symbiotic nitrogen-fixing nodule development and could be widely applied in broad leguminous plants.
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Affiliation(s)
- Yinglun Fan
- College of Agriculture, Liaocheng University, Liaocheng, 252000 China
| | - Xiuyuan Wang
- College of Agriculture, Liaocheng University, Liaocheng, 252000 China
| | - Haiyun Li
- College of Agriculture, Liaocheng University, Liaocheng, 252000 China
| | - Shuang Liu
- College of Agriculture, Liaocheng University, Liaocheng, 252000 China
| | - Liangshen Jin
- College of Agriculture, Liaocheng University, Liaocheng, 252000 China
| | - Yanyan Lyu
- College of Agriculture, Liaocheng University, Liaocheng, 252000 China
| | - Mengdi Shi
- College of Agriculture, Liaocheng University, Liaocheng, 252000 China
| | - Sirui Liu
- College of Agriculture, Liaocheng University, Liaocheng, 252000 China
| | - Xinyue Yang
- College of Agriculture, Liaocheng University, Liaocheng, 252000 China
| | - Shanhua Lyu
- College of Agriculture, Liaocheng University, Liaocheng, 252000 China
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5
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Young JK, Gasior SL, Jones S, Wang L, Navarro P, Vickroy B, Barrangou R. The repurposing of type I-E CRISPR-Cascade for gene activation in plants. Commun Biol 2019; 2:383. [PMID: 31646186 PMCID: PMC6802105 DOI: 10.1038/s42003-019-0637-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 09/27/2019] [Indexed: 02/07/2023] Open
Abstract
CRISPR-Cas systems are robust and facile tools for manipulating the genome, epigenome and transcriptome of eukaryotic organisms. Most groups use class 2 effectors, such as Cas9 and Cas12a, however, other CRISPR-Cas systems may provide unique opportunities for genome engineering. Indeed, the multi-subunit composition of class 1 systems offers to expand the number of domains and functionalities that may be recruited to a genomic target. Here we report DNA targeting in Zea mays using a class 1 type I-E CRISPR-Cas system from S. thermophilus. First, we engineer its Cascade complex to modulate gene expression by tethering a plant transcriptional activation domain to 3 different subunits. Next, using an immunofluorescent assay, we confirm Cascade cellular complex formation and observe enhanced gene activation when multiple subunits tagged with the transcriptional activator are combined. Finally, we examine Cascade mediated gene activation at chromosomal DNA targets by reprogramming Zea mays cells to change color.
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Affiliation(s)
- Joshua K. Young
- Department of Molecular Engineering, Corteva Agriscience™, Johnston, IA 50131 USA
| | - Stephen L. Gasior
- Department of Molecular Engineering, Corteva Agriscience™, Johnston, IA 50131 USA
| | - Spencer Jones
- Department of Molecular Engineering, Corteva Agriscience™, Johnston, IA 50131 USA
| | - Lijuan Wang
- Department of Molecular Engineering, Corteva Agriscience™, Johnston, IA 50131 USA
| | - Pedro Navarro
- Department of Molecular Engineering, Corteva Agriscience™, Johnston, IA 50131 USA
| | - Becca Vickroy
- Department of Molecular Engineering, Corteva Agriscience™, Johnston, IA 50131 USA
| | - Rodolphe Barrangou
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC 27695 USA
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Laufer M, Mohammad H, Christ DS, Riedel D, Maiss E, Varrelmann M, Liebe S. Fluorescent labelling of Beet necrotic yellow vein virus and Beet soil-borne mosaic virus for co- and superinfection experiments in Nicotiana benthamiana. J Gen Virol 2018; 99:1321-1330. [PMID: 30058995 DOI: 10.1099/jgv.0.001122] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024] Open
Abstract
Infectious full-length clones of Beet necrotic yellow vein virus (BNYVV) and Beet soil-borne mosaic virus (BSBMV), both genus Benyvirus, were used for fluorescent labelling with the objective to study their interaction in coinfection and superinfection experiments. Fluorescent labelling was achieved by replacing a part of the RNA2 encoded coat protein read-through domain with either GFP or mRFP fluorescent marker proteins. This resulted in a translational fusion comprising the coat and the fluorescent protein. The labelled viruses were infectious and moved systemically in Nicotiana benthamiana, producing wild-type-like symptoms. Virus particles could be observed by electron microscopy, demonstrating that the viral read-through domain is dispensable for particle formation. Coinfection experiments revealed a spatial separation of differentially labelled populations of both identical and different Benyvirus species after N. benthamiana agro-inoculation. Identical observations were obtained when Tobacco rattle virus (TRV) was differentially labelled and used for coinfection. In contrast, coinfections of BSBMV with Potato virus X (PVX) or TRV resulted in many co-infected cells lacking spatial separation. Micro-projectile co-bombardment of N. benthamiana leaves revealed that two differently labelled populations of the same virus co-infected only a few cells before starting to separate. In superinfection experiments with N. benthamiana, BSBMV and BNYVV were unable to establish a secondary infection in plants that were previously infected with BNYVV or BSBMV. Taken together, this is the first work to describe the interaction between two economically important Benyviruses using fluorescence-labelled full-length clones.
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Affiliation(s)
- Marlene Laufer
- 1Department of Phytopathology, Institute of Sugar Beet Research, 37079 Göttingen, Germany
| | - Hamza Mohammad
- 2Department of Phytomedicine, Plant Virology, Institute of Horticultural Production Systems, Leibniz University, 30419 Hannover, Germany
| | - Daniela S Christ
- 1Department of Phytopathology, Institute of Sugar Beet Research, 37079 Göttingen, Germany
| | - Dietmar Riedel
- 3Laboratory of Electron Microscopy, Max-Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Edgar Maiss
- 2Department of Phytomedicine, Plant Virology, Institute of Horticultural Production Systems, Leibniz University, 30419 Hannover, Germany
| | - Mark Varrelmann
- 1Department of Phytopathology, Institute of Sugar Beet Research, 37079 Göttingen, Germany
| | - Sebastian Liebe
- 1Department of Phytopathology, Institute of Sugar Beet Research, 37079 Göttingen, Germany
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Abstract
The use of transgenics in fish is a relatively recent development for advancing understanding of genetic mechanisms and developmental processes, improving aquaculture, and for pharmaceutical discovery. Transgenic fish have also been applied in ecotoxicology where they have the potential to provide more advanced and integrated systems for assessing health impacts of chemicals. The zebrafish (Daniorerio) is the most popular fish for transgenic models, for reasons including their high fecundity, transparency of their embryos, rapid organogenesis and availability of extensive genetic resources. The most commonly used technique for producing transgenic zebrafish is via microinjection of transgenes into fertilized eggs. Transposon and meganuclease have become the most reliable methods for insertion of the genetic construct in the production of stable transgenic fish lines. The GAL4-UAS system, where GAL4 is placed under the control of a desired promoter and UAS is fused with a fluorescent marker, has greatly enhanced model development for studies in ecotoxicology. Transgenic fish have been developed to study for the effects of heavy metal toxicity (via heat-shock protein genes), oxidative stress (via an electrophile-responsive element), for various organic chemicals acting through the aryl hydrocarbon receptor, thyroid and glucocorticoid response pathways, and estrogenicity. These models vary in their sensitivity with only very few able to detect responses for environmentally relevant exposures. Nevertheless, the potential of these systems for analyses of chemical effects in real time and across multiple targets in intact organisms is considerable. Here we illustrate the techniques used for generating transgenic zebrafish and assess progress in the development and application of transgenic fish (principally zebrafish) for studies in environmental toxicology. We further provide a viewpoint on future development opportunities.
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Affiliation(s)
- Okhyun Lee
- Biosciences, College of Life & Environmental Sciences, University of Exeter , Exeter, Devon , UK
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Liu D, Leib K, Zhao P, Kogel KH, Langen G. Phylogenetic analysis of barley WRKY proteins and characterization of HvWRKY1 and -2 as repressors of the pathogen-inducible gene HvGER4c. Mol Genet Genomics 2014; 289:1331-45. [PMID: 25138194 DOI: 10.1007/s00438-014-0893-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Accepted: 07/26/2014] [Indexed: 11/25/2022]
Abstract
The WRKY transcription factors belong to an evolutionarily conserved superprotein family predominantly present in the plant kingdom. WRKY proteins of barley are not yet fully annotated and most of them are not functionally characterized. We performed a genome-wide identification of WRKY members based on the recently accessible barley draft genome sequence and full-length cDNA datasets. As a result, 34 novel putative proteins have been identified which extend the existing list for barley WRKYs to 94. Phylogenetic analysis of the WRKY domains allowed ranking into three groups (I, II, III), with an expansion in group III in monocots. Two members of subgroup IIa, the wound and pathogen-inducible HvWRKY1 and HvWRKY2, are known as negative defense regulators. Here, we demonstrate that both transcription factors repress the activity of the powdery mildew-induced promoter of HvGER4c, a germin-like defense-related protein. The repression did not require the negative defense regulator MLO nor was it affected by the presence of the R protein MLA12. Moreover, the expression of the Arabidopsis ortholog AtWRKY40 in barley compromised basal resistance to powdery mildew, providing evidence for functional conservation of sequence-related WRKY proteins across monocots and dicots.
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Affiliation(s)
- Dilin Liu
- Research Centre for BioSystems, Land Use, and Nutrition (IFZ Giessen), Institute of Phytopathology and Applied Zoology, Justus Liebig University Giessen, 35392, Giessen, Germany
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Mann DGJ, Abercrombie LL, Rudis MR, Millwood RJ, Dunlap JR, Stewart CN. Very bright orange fluorescent plants: endoplasmic reticulum targeting of orange fluorescent proteins as visual reporters in transgenic plants. BMC Biotechnol 2012; 12:17. [PMID: 22554231 PMCID: PMC3443454 DOI: 10.1186/1472-6750-12-17] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 04/25/2012] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND The expression of fluorescent protein (FP) genes as real-time visual markers, both transiently and stably, has revolutionized plant biotechnology. A palette of colors of FPs is now available for use, but the diversity has generally been underutilized in plant biotechnology. Because of the green and far-red autofluorescent properties of many plant tissues and the FPs themselves, red and orange FPs (RFPs, and OFPs, respectfully) appear to be the colors with maximum utility in plant biotechnology. Within the color palette OFPs have emerged as the brightest FP markers in the visible spectra. This study compares several native, near-native and modified OFPs for their "brightness" and fluorescence, therefore, their usability as marker genes in transgenic plant tissues. RESULTS The OFPs DsRed2, tdTomato, mOrange and pporRFP were all expressed under the control of the CaMV 35S promoter in agroinfiltration-mediated transient assays in Nicotiana benthamiana. Each of these, as well as endoplasmic reticulum (ER)-targeted versions, were stably expressed in transgenic Nicotiana tabacum and Arabidopsis thaliana. Congruent results were observed between transient and stable assays. Our results demonstrated that there are several adequate OFP genes available for plant transformation, including the new pporRFP, an unaltered tetramer from the hard coral Porites porites. When the tandem dimer tdTomato and the monomeric mOrange were targeted to the ER, dramatic, ca. 3-fold, increase in plant fluorescence was observed. CONCLUSIONS From our empirical data, and a search of the literature, it appears that tdTomato-ER and mOrange-ER are the two highest fluorescing FPs available as reporters for transgenic plants. The pporRFP is a brightly fluorescing tetramer, but all tetramer FPs are far less bright than the ER-targeted monomers we report here.
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Affiliation(s)
- David GJ Mann
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Laura L Abercrombie
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Mary R Rudis
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
| | - Reggie J Millwood
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
| | - John R Dunlap
- Division of Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - C Neal Stewart
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
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10
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Mann DGJ, Lafayette PR, Abercrombie LL, King ZR, Mazarei M, Halter MC, Poovaiah CR, Baxter H, Shen H, Dixon RA, Parrott WA, Neal Stewart C. Gateway-compatible vectors for high-throughput gene functional analysis in switchgrass (Panicum virgatum L.) and other monocot species. PLANT BIOTECHNOLOGY JOURNAL 2012; 10:226-36. [PMID: 21955653 DOI: 10.1111/j.1467-7652.2011.00658.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Switchgrass (Panicum virgatum L.) is a C4 perennial grass and has been identified as a potential bioenergy crop for cellulosic ethanol because of its rapid growth rate, nutrient use efficiency and widespread distribution throughout North America. The improvement of bioenergy feedstocks is needed to make cellulosic ethanol economically feasible, and genetic engineering of switchgrass is a promising approach towards this goal. A crucial component of creating transgenic switchgrass is having the capability of transforming the explants with DNA sequences of interest using vector constructs. However, there are limited options with the monocot plant vectors currently available. With this in mind, a versatile set of Gateway-compatible destination vectors (termed pANIC) was constructed to be used in monocot plants for transgenic crop improvement. The pANIC vectors can be used for transgene overexpression or RNAi-mediated gene suppression. The pANIC vector set includes vectors that can be utilized for particle bombardment or Agrobacterium-mediated transformation. All the vectors contain (i) a Gateway cassette for overexpression or silencing of the target sequence, (ii) a plant selection cassette and (iii) a visual reporter cassette. The pANIC vector set was functionally validated in switchgrass and rice and allows for high-throughput screening of sequences of interest in other monocot species as well.
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Affiliation(s)
- David G J Mann
- Department of Plant Sciences, The University of Tennessee, Knoxville, TN, USA.
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11
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Lin MH, Gresshoff PM, Indrasumunar A, Ferguson BJ. pHairyRed: a novel binary vector containing the DsRed2 reporter gene for visual selection of transgenic hairy roots. MOLECULAR PLANT 2011; 4:537-45. [PMID: 21324970 DOI: 10.1093/mp/ssq084] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We developed a new plant transformation vector, pHairyRed, for enabling high throughput, non-destructive selection of Agrobacterium rhizogenes-mediated 'hairy-root' transformation. pHairyRed allows easy in planta visualization of transgenic tissue with minimal disturbance to the plant. The DsRed2 reporter gene, encoding a red fluorescent protein, was cloned to yield pHairyRed (harbouring a multiple cloning site), which was used with the highly efficient K599 A. rhizogenes strain to infect soybean (Glycine max L. Merrill) plants. DsRed2 fluorescence was easily detected in planta for the duration of a 5-week study with negligible levels of background autofluorescence. This enabled visual selection of transformed roots and subsequent excission of non-transformed roots. pHairyRed-transformed roots nodulated normally when inoculated with Bradyrhizobium japonicum. Within the nodule, DsRed2 fluorescence was plant-specific, being absent in the bacteroid-dominated nodule infected zone. To test the reliability of pHairyRed as a high-fidelity binary vector reporter system, the gene encoding the soybean Nod factor receptor, GmNFR1α, was cloned into the vector for use in a complementation study with a non-nodulating nfr1α mutant of soybean. Complementation was achieved and, without exception, DsRed2 fluorescence was detected in all hairy roots that successfully formed nodules (100%, n = 34). We anticipate broad application of this reporter system for the further analysis of root-related events in soybean and related legumes.
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Affiliation(s)
- Meng-Han Lin
- Australian Research Council Centre of Excellence for Integrative Legume Research, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia
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12
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Hong H, Yang Y, Cai W. Imaging gene expression in live cells and tissues. Cold Spring Harb Protoc 2011; 2011:pdb.top103. [PMID: 21460057 DOI: 10.1101/pdb.top103] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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13
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Eichmann R, Bischof M, Weis C, Shaw J, Lacomme C, Schweizer P, Duchkov D, Hensel G, Kumlehn J, Hückelhoven R. BAX INHIBITOR-1 is required for full susceptibility of barley to powdery mildew. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2010; 23:1217-27. [PMID: 20687811 DOI: 10.1094/mpmi-23-9-1217] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
BAX INHIBITOR-1 (BI-1) is one of the few proteins known to have cross-kingdom conserved functions in negative control of programmed cell death. Additionally, barley BI-1 (HvBI-1) suppresses defense responses and basal resistance to the powdery mildew fungus Blumeria graminis f. sp. hordei and enhances resistance to cell death-provoking fungi when overexpressed in barley. Downregulation of HvBI-1 by transient-induced gene silencing or virus-induced gene silencing limited susceptibility to B. graminis f. sp. hordei, suggesting that HvBI-1 is a susceptibility factor toward powdery mildew. Transient silencing of BI-1 did not limit supersusceptibility induced by overexpression of MLO. Transgenic barley plants harboring an HvBI-1 RNA interference (RNAi) construct displayed lower levels of HvBI-1 transcripts and were less susceptible to powdery mildew than wild-type plants. At the cellular level, HvBI-1 RNAi plants had enhanced resistance to penetration by B. graminis f. sp. hordei. These data support a function of BI-1 in modulating cell-wall-associated defense and in establishing full compatibility of B. graminis f. sp. hordei with barley.
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Affiliation(s)
- Ruth Eichmann
- Lehrstuhl für Phytopathologie, Technische Universität München, Emil-Ramann-Strasse 2, D-85350 Freising-Weihenstephan, Germany.
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14
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Jung S, Choi JH, Hong C, Lee H, Park YK, Shin JH, Park JW, Park SH. A new reporter vector system based on flow-cytometry to detect promoter activity. Immune Netw 2009; 9:243-7. [PMID: 20157611 PMCID: PMC2816957 DOI: 10.4110/in.2009.9.6.243] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2009] [Revised: 11/27/2009] [Accepted: 12/09/2009] [Indexed: 12/01/2022] Open
Abstract
In this study, we report the development of a new dual reporter vector system for the analysis of promoter activity. This system employs green fluorescence emitting protein, EGFP, as a reporter, and uses red fluorescence emitting protein, DsRed, as a transfection control in a single vector. The expression of those two proteins can be readily detected via flow cytometry in a single analysis, with no need for any further manipulation after transfection. As this system allows for the simultaneous detection of both the control and reporter proteins in the same cells, only transfected cells which express the control protein, DsRed, can be subjected to promoter activity analysis, via the gating out of all un-transfected cells. This results in a dramatic increase in the promoter activity detection sensitivity. This novel reporter vector system should prove to be a simple and efficient method for the analysis of promoter activity.
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Affiliation(s)
- Sundo Jung
- School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea
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15
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Schultheiss H, Preuss J, Pircher T, Eichmann R, Hückelhoven R. Barley RIC171 interacts with RACB in planta and supports entry of the powdery mildew fungus. Cell Microbiol 2008; 10:1815-26. [PMID: 18466344 DOI: 10.1111/j.1462-5822.2008.01167.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
RHO-like GTPases of plants (ROPs, also called RACs) are involved in plant development and interaction with the environment. The barley ROP protein RACB is involved in susceptibility to the fungal pathogen Blumeria graminis f.sp. hordei (Bgh). By screening barley sequence databases for potential protein interactors of plant RHO-like proteins, we identified a ROP-interactive CRIB (CDC42/RAC interactive binding) motif containing protein of 171 amino acids (RIC171). The protein interacted with constitutively activated RACB in a targeted yeast two-hybrid assay. By use of split yellow fluorescing protein fusions, we demonstrated that RIC171 interacts with constitutively activated (CA) RACB-G15V but not with dominant negative RACB-T20N in planta. Transient overexpression of RIC171, similar to overexpression of CA RACB-G15V, rendered epidermal cells more susceptible to penetration by Bgh. In contrast, expression of a 46-amino-acid RIC171-CRIB peptide, which was sufficient to interact with CA RACB-G15V, had a dominant negative effect and reduced susceptibility to Bgh. A red fluorescing DsRED-RIC171 fusion protein colocalized with green fluorescing GFP-RACB-G15V at the cell periphery. Coexpression with CA RACB-G15V but not with RACB-T20N increased peripheral localization of DsRED-RIC171. Additionally, DsRED-RIC171 accumulated at sites of fungal attack, suggesting enhanced ROP activity at sites of attempted fungal penetration.
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Affiliation(s)
- Holger Schultheiss
- Lehrstuhl für Phytopathologie, Technische Universität München, Freising, Germany
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16
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Zaltsman A, Yi BY, Krichevsky A, Gafni Y, Citovsky V. Yeast-plant coupled vector system for identification of nuclear proteins. PLANT PHYSIOLOGY 2007; 145:1264-71. [PMID: 17704231 PMCID: PMC2151716 DOI: 10.1104/pp.107.105973] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Nuclear proteins are involved in many critical biological processes within plant cells and, therefore, are in the focus of studies that usually begin with demonstrating that the protein of interest indeed exhibits nuclear localization. Thus, studies of plant nuclear proteins would be facilitated by a convenient experimental system for identification of proteins that are actively imported into the cell nucleus and visualization of their nuclear accumulation in vivo. To this end, we developed a system of vectors that allows screening for cDNAs coding for nuclear proteins in a simple genetic assay in yeast cells, and verification of nuclear accumulation in planta following one-step transfer and autofluorescent tagging of the identified clones into a multiple cloning site-compatible and reading frame-compatible plant expression vector. In a recommended third experimental step, the plant expression cassette containing the identified clone can be transferred, also by a one-step cloning, into a binary multigene expression vector for transient or stable coexpression with any other proteins.
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Affiliation(s)
- Adi Zaltsman
- Department of Biochemistry and Cell Biology, State University of New York, Stony Brook, New York 11794-5215, USA
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17
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Ghazala W, Varrelmann M. Tobacco rattle virus 29K movement protein is the elicitor of extreme and hypersensitive-like resistance in two cultivars of Solanum tuberosum. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2007; 20:1396-405. [PMID: 17977151 DOI: 10.1094/mpmi-20-11-1396] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Leaf infection experiments were used to analyze the host responses of Solanum tuberosum cultivars known to be resistant or susceptible to natural, nematode-mediated infection of tubers and necrosis induction ("spraing") by Tobacco rattle virus (TRV) isolate PpK20 (TRV-PpK20). Extreme and hypersensitive-like resistance (ER and HR-like, respectively) as well as spreading veinal necrosis and systemic infection were observed. Agroinfection of leaves with a DsRed-expressing TRV cDNA clone revealed ER to function on the single-cell level, inhibiting virus replication and possessing the potential to initiate a cell death response. HR-like necrosis was characterized by initial virus replication and cell-to-cell movement before the onset of necrosis. Transient agroexpression and Potato virus X (PVX)-mediated expression assays demonstrated that the 29K-PpK20 movement protein (MP) can elicit ER and HR-like cell-death. A TRV isolate, PpO85M, known to overcome the resistance to spraing in plants that are resistant to TRV-PpK20 encoded a variant 29K protein which did not elicit HR in PpK20-HR plants. Our results show that the TRV MP is the elicitor of both ER and HR-like cell-death, that no other TRV-encoded proteins or RNA replication are required for its elicitor activity, and that the host reactions are likely to be controlled by single dominant resistance genes.
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Affiliation(s)
- Walid Ghazala
- University of Göttingen, Department of Crop Sciences, Section Plant Virology, Grisebachstr. 6, 37077 Göttingen, Germany
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18
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Hofius D, Maier AT, Dietrich C, Jungkunz I, Börnke F, Maiss E, Sonnewald U. Capsid protein-mediated recruitment of host DnaJ-like proteins is required for Potato virus Y infection in tobacco plants. J Virol 2007; 81:11870-80. [PMID: 17715215 PMCID: PMC2168797 DOI: 10.1128/jvi.01525-07] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2007] [Accepted: 08/15/2007] [Indexed: 11/20/2022] Open
Abstract
The capsid protein (CP) of potyviruses is required for various steps during plant infection, such as virion assembly, cell-to-cell movement, and long-distance transport. This suggests a series of compatible interactions with putative host factors which, however, are largely unknown. By using the yeast two-hybrid system the CP from Potato virus Y (PVY) was found to interact with a novel subset of DnaJ-like proteins from tobacco, designated NtCPIPs. Mutational analysis identified the CP core region, previously shown to be essential for virion formation and plasmodesmal trafficking, as the interacting domain. The ability of NtCPIP1 and NtCPIP2a to associate with PVY CP could be confirmed in vitro and was additionally verified in planta by bimolecular fluorescence complementation. The biological significance of the interaction was assayed by PVY infection of agroinfiltrated leaves and transgenic tobacco plants that expressed either full-length or J-domain-deficient variants of NtCPIPs. Transient expression of truncated dominant-interfering NtCPIP2a but not of the functional protein resulted in strongly reduced accumulation of PVY in the inoculated leaf. Consistently, stable overexpression of J-domain-deficient variants of NtCPIP1 and NtCPIP2a dramatically increased the virus resistance of various transgenic lines, indicating a critical role of functional NtCPIPs during PVY infection. The negative effect of impaired NtCPIP function on viral pathogenicity seemed to be the consequence of delayed cell-to-cell movement, as visualized by microprojectile bombardment with green fluorescent protein-tagged PVY. Therefore, we propose that NtCPIPs act as important susceptibility factors during PVY infection, possibly by recruiting heat shock protein 70 chaperones for viral assembly and/or cellular spread.
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Affiliation(s)
- Daniel Hofius
- Copenhagen Biocenter, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark.
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19
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Ajjawi I, Rodriguez Milla MA, Cushman J, Shintani DK. Thiamin pyrophosphokinase is required for thiamin cofactor activation in Arabidopsis. PLANT MOLECULAR BIOLOGY 2007; 65:151-62. [PMID: 17611796 DOI: 10.1007/s11103-007-9205-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2006] [Accepted: 06/24/2007] [Indexed: 05/08/2023]
Abstract
Thiamin pyrophosphate (TPP) is an essential enzyme cofactor required for the viability of all organisms. Whether derived from exogenous sources or through de novo synthesis, thiamin must be pyrophosphorylated for cofactor activation. The enzyme thiamin pyrophosphokinase (TPK) catalyzes the conversion of free thiamin to TPP in plants and other eukaryotic organisms and is central to thiamin cofactor activation. While TPK activity has been observed in a number of plant species, the corresponding gene/protein has until now not been identified or characterized for its role in thiamin metabolism. Here we report the functional identification of two Arabidopsis TPK genes, AtTPK1 and AtTPK2 and the enzymatic characterization of the corresponding proteins. AtTPK1 and AtTPK2 are biochemically redundant cytosolic proteins that are similarly expressed throughout different plant tissues. The essential nature of TPKs in plant metabolism is reflected in the observation that while single gene knockouts of either AtTPK1 or AtTPK2 were viable, the double mutant possessed a seedling lethal phenotype. HPLC analysis revealed the double mutant is nearly devoid of TPP and instead accumulates the precursor of the TPK reaction, free thiamin. These results suggest that TPK activity provides the sole mechanism by which exogenous and de novo derived thiamin is converted to the enzyme cofactor TPP.
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Affiliation(s)
- Imad Ajjawi
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557, USA
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20
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Dietrich C, Miller J, McKenzie G, Palkovics L, Balázs E, Palukaitis P, Maiss E. No recombination detected in artificial potyvirus mixed infections and between potyvirus derived transgenes and heterologous challenging potyviruses. ENVIRONMENTAL BIOSAFETY RESEARCH 2007; 6:207-18. [PMID: 18001687 DOI: 10.1051/ebr:2007042] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Risk-assessment studies of virus-resistant transgenic plants (VRTPs) focussing on recombination of a plant virus with a transgenic sequence of a different virus should include a comparison of recombination frequencies between viruses in double-infected non-transgenic plants with those observed in singly infected transgenic plants to estimate recombination incidence in VRTPs. In this study, the occurrence of recombination events was investigated in non-transgenic plants double-infected with two different potyviruses, as well as in potyviral genomes in singly infected transgenic plants expressing potyvirus sequences. Different potyviruses, namely Potato virus A (PVA), Tobacco vein mottling virus (TVMV), two strains of Potato virus Y (PVY-O, PVY-H) and two strains of Plum pox virus (PPV-NAT, PPV-SK68), were used in three combinations for double infection of a common host. Furthermore, transgenic plants expressing either potyviral coat protein (CP), helicase (CI) or polymerase (NIb) coding sequences (PPV-NAT-CP, PVY-CI, PVY-NIb) were singly-infected with a heterologous potyvirus, which was not targeted by the respective transgenic resistance. To identify recombinant potyviral sequences, a sensitive RT-PCR was developed to detect up to one recombinant molecule out of 10(6) parental molecules. In 304 mixed infected non-transgenic plants, 92 mixed and 164 single infected transgenic plants screened for recombinant sequences no recombinant potyviral sequence was found. These results indicate that recombination events between different potyviruses in mixed infections and between a potyvirus infecting a potyvirus-resistant transgenic plant are likely to be very infrequent.
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Affiliation(s)
- Christof Dietrich
- German Collection of Microorganisms and Cell Cultures, Plant Virus Division, Inhoffenstrasse 7b, 38124 Braunschweig, Germany
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21
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Bukovinszki A, Götz R, Johansen E, Maiss E, Balázs E. The role of the coat protein region in symptom formation on Physalis floridana varies between PVY strains. Virus Res 2007; 127:122-5. [PMID: 17482305 DOI: 10.1016/j.virusres.2007.03.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2007] [Revised: 03/22/2007] [Accepted: 03/23/2007] [Indexed: 10/23/2022]
Abstract
The Potato virus Y (PVY) cDNA full-length clone created by Jakab et al. [Jakab, G., Droz, E., Brigneti, G., Baulcombe, D., Malnoë, P., 1997. Infectious in vivo and in vitro transcripts from a full-length cDNA clone of PVY-N605, a Swiss necrotic isolate of potato virus Y. J. Gen. Virol. 78, 3141-3145] was stabilized by inserting three introns into putatively toxic genes. Using this clone, hybrid viruses were constructed by in vitro recombination. The PVY-N/NTN and PVY-N/O chimeras carried the 3' end of NIb, the whole CP and 3'UTR region of PVY(NTN) and PVY(O), respectively, in a PVY(N) genetic background. The clones proved to be stable after several passages by re-sequencing the exchanged region. Both hybrid viruses showed reduced infectivity in particle bombardment experiments, but they were suitable for further mechanical plant inoculation. In five of the six host plant species, inoculated with the two chimeras and three parental strains, the chimeras produced similar symptoms to those of PVY(N). By contrast, Physalis floridana reacted with different pattern of symptoms. In this species, the symptoms caused by the N/O hybrid were similar to those of the 3'NIb-CP-donating PVY(O) strain, and not to those of the background (PVY(N)). The results suggest that symptom determinants may be different even between strains of the same virus species in a particular host.
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22
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Anand A, Krichevsky A, Schornack S, Lahaye T, Tzfira T, Tang Y, Citovsky V, Mysore KS. Arabidopsis VIRE2 INTERACTING PROTEIN2 is required for Agrobacterium T-DNA integration in plants. THE PLANT CELL 2007; 19:1695-708. [PMID: 17496122 PMCID: PMC1913729 DOI: 10.1105/tpc.106.042903] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2006] [Revised: 02/04/2007] [Accepted: 04/27/2007] [Indexed: 05/15/2023]
Abstract
Agrobacterium tumefaciens-mediated genetic transformation is an efficient tool for genetic engineering of plants. VirE2 is a single-stranded DNA binding Agrobacterium protein that is transported into the plant cell and presumably protects the T-DNA from degradation. Using a yeast two-hybrid system, we identified Arabidopsis thaliana VIRE2-INTERACTING PROTEIN2 (VIP2) with a NOT domain that is conserved in both plants and animals. Furthermore, we provide evidence supporting VIP2 interaction with VIP1, a basic domain/leucine zipper motif-containing protein required for nuclear import and integration of T-DNA. Virus-induced gene silencing of VIP2 in Nicotiana benthamiana and characterization of the Arabidopsis vip2 mutant (At vip2) demonstrate that VIP2 is required for Agrobacterium-mediated stable transformation but not for transient transformation. Assays based upon a promoter-trap vector and quantification of T-DNA integration further confirmed VIP2 involvement in T-DNA integration. Interestingly, VIP2 transcripts were induced to a greater extent over prolonged periods after infection with a T-DNA transfer-competent Agrobacterium strain compared with the transfer-deficient Agrobacterium strain. Transcriptome analyses of At vip2 suggest that VIP2 is likely a transcriptional regulator, and the recalcitrancy to transformation in At vip2 is probably due to the combination of muted gene expression response upon Agrobacterium infection and repression of histone genes resulting in decreased T-DNA integration events.
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Affiliation(s)
- Ajith Anand
- Plant Biology Division, Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401, USA
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23
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Nishizawa K, Kita Y, Kitayama M, Ishimoto M. A red fluorescent protein, DsRed2, as a visual reporter for transient expression and stable transformation in soybean. PLANT CELL REPORTS 2006; 25:1355-61. [PMID: 16841215 DOI: 10.1007/s00299-006-0210-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2006] [Revised: 06/21/2006] [Accepted: 06/26/2006] [Indexed: 05/10/2023]
Abstract
Fluorescent proteins such as green fluorescent protein (GFP) from Aequorea victoria are often used as markers for transient expression and stable transformation in plants, given that their detection does not require a substrate and they can be monitored in a nondestructive manner. We have now evaluated the red fluorescent protein DsRed2 (a mutant form of DsRed from Discosoma sp.) for its suitability as a visual marker in combination with antibiotic selection for genetic transformation of soybean [Glycine max (L.) Merrill]. Transient and stable expression of DsRed2 in somatic embryos was readily detected by fluorescence microscopy, allowing easy confirmation of gene introduction. We obtained several fertile transgenic lines, including homozygous lines, that grew and produced seeds in an apparently normal manner. The red fluorescence of DsRed2 was detected by fluorescence microscopy without background fluorescence in both leaves and seeds of the transgenic plants. Furthermore, in contrast to seeds expressing GFP, those expressing DsRed2 were readily identifiable even under white light by the color conferred by the transgene product. The protein composition of seeds was not affected by the introduction of DsRed2, with the exception of the accumulation of DsRed2 itself, which was detectable as an additional band on electrophoresis. These results indicate that DsRed2 is a suitable reporter (even more suitable than GFP) for genetic transformation of soybean.
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Affiliation(s)
- Keito Nishizawa
- National Agricultural Research Center for Hokkaido Region, Toyohira, Sapporo, Hokkaido, 062-8555, Japan
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24
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Li J, Krichevsky A, Vaidya M, Tzfira T, Citovsky V. Uncoupling of the functions of the Arabidopsis VIP1 protein in transient and stable plant genetic transformation by Agrobacterium. Proc Natl Acad Sci U S A 2005; 102:5733-8. [PMID: 15824315 PMCID: PMC556277 DOI: 10.1073/pnas.0404118102] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2004] [Indexed: 11/18/2022] Open
Abstract
Agrobacterium-mediated genetic transformation of plants, a unique example of transkingdom DNA transfer, requires the presence of several proteins encoded by the host cell. One such cellular factor is VIP1, an Arabidopsis protein proposed to interact with and facilitate import of the bacterial DNA-protein transport (T) complexes into the plant cell nucleus. Thus, VIP1 is required for transient expression of the bacterial DNA, an early step in the transformation process. However, the role of VIP1 in subsequent transformation events leading to the stable expression of bacterial DNA was unexplored. Here, we used reverse genetics to dissect VIP1 functionally and demonstrate its involvement in the stable genetic transformation of Arabidopsis plants by Agrobacterium. Our data indicate that the ability of VIP1 to interact with the VirE2 protein component of the T-complex and localize to the cell nucleus is sufficient for transient genetic transformation, whereas its ability to form homomultimers and interact with the host cell H2A histone in planta is required for tumorigenesis and, by implication, stable genetic transformation.
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Affiliation(s)
- Jianxiong Li
- Department of Biochemistry and Cell Biology, State University of New York, Stony Brook, NY 11794-5215, USA
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25
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Lacroix B, Vaidya M, Tzfira T, Citovsky V. The VirE3 protein of Agrobacterium mimics a host cell function required for plant genetic transformation. EMBO J 2005; 24:428-37. [PMID: 15616576 PMCID: PMC545813 DOI: 10.1038/sj.emboj.7600524] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2004] [Accepted: 11/26/2004] [Indexed: 11/08/2022] Open
Abstract
To genetically transform plants, Agrobacterium exports its transferred DNA (T-DNA) and several virulence (Vir) proteins into the host cell. Among these proteins, VirE3 is the only one whose biological function is completely unknown. Here, we demonstrate that VirE3 is transferred from Agrobacterium to the plant cell and then imported into its nucleus via the karyopherin alpha-dependent pathway. In addition to binding plant karyopherin alpha, VirE3 interacts with VirE2, a major bacterial protein that directly associates with the T-DNA and facilitates its nuclear import. The VirE2 nuclear import in turn is mediated by a plant protein, VIP1. Our data indicate that VirE3 can mimic this VIP1 function, acting as an 'adapter' molecule between VirE2 and karyopherin alpha and 'piggy-backing' VirE2 into the host cell nucleus. As VIP1 is not an abundant protein, representing one of the limiting factors for transformation, Agrobacterium may have evolved to produce and export to the host cells its own virulence protein that at least partially complements the cellular VIP1 function necessary for the T-DNA nuclear import and subsequent expression within the infected cell.
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Affiliation(s)
- Benoît Lacroix
- Department of Biochemistry and Cell Biology, State University of New York, Stony Brook, NY, USA
| | - Manjusha Vaidya
- Department of Biochemistry and Cell Biology, State University of New York, Stony Brook, NY, USA
| | - Tzvi Tzfira
- Department of Biochemistry and Cell Biology, State University of New York, Stony Brook, NY, USA
| | - Vitaly Citovsky
- Department of Biochemistry and Cell Biology, State University of New York, Stony Brook, NY, USA
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26
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Opalski KS, Schultheiss H, Kogel KH, Hückelhoven R. The receptor-like MLO protein and the RAC/ROP family G-protein RACB modulate actin reorganization in barley attacked by the biotrophic powdery mildew fungus Blumeria graminis f.sp. hordei. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2005; 41:291-303. [PMID: 15634205 DOI: 10.1111/j.1365-313x.2004.02292.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Cytoskeleton remodelling is a crucial process in determining the polarity of dividing and growing plant cells, as well as during interactions with the environment. Nothing is currently known about the proteins, which regulate actin remodelling during interactions with invading pathogens. The biotrophic powdery mildew fungus Blumeria graminis f.sp. hordei (Bgh) invades susceptible barley (Hordeum vulgare L.) by penetrating epidermal cells, which remain intact during fungal development. In contrast, resistant host plants prevent infection by inhibiting penetration through apoplastic mechanisms, which require focusing defence reactions on the site of attack. We stained actin filaments in a susceptible Mlo-genotype and a near-isogenic race-non-specifically resistant barley mlo5-mutant genotype using fluorescence-labelled phalloidin after chemical fixation. This revealed that the actin cytoskeleton is differentially reorganized in susceptible and resistant hosts challenged by Bgh. Actin filaments were polarized towards the sites of attempted penetration in the resistant host, whereas when susceptible hosts were penetrated, a more subtle reorganization took place around fungal haustoria. Strong actin filament focusing towards sites of fungal attack was closely associated with successful prevention of penetration. Actin focusing was less frequent and seemingly delayed in susceptible wild-type barley expressing the susceptibility factor MLO. Additionally, single cell overexpression of a constitutively activated RAC/ROP G-protein, CA RACB, another potential host susceptibility factor and hypothetical actin cytoskeleton regulator, partly inhibited actin reorganization when under attack from Bgh, whereas knockdown of RACB promoted actin focusing. We conclude that RACB and, potentially, MLO are host proteins involved in the modulation of actin reorganization and cell polarity in the interaction of barley with Bgh.
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Affiliation(s)
- Krystina S Opalski
- Institute of Phytopathology and Applied Zoology, Justus-Liebig-University Giessen, Heinrich-Buff Ring 26-32, D-35392 Giessen, Germany
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27
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Eichmann R, Schultheiss H, Kogel KH, Hückelhoven R. The barley apoptosis suppressor homologue BAX inhibitor-1 compromises nonhost penetration resistance of barley to the inappropriate pathogen Blumeria graminis f. sp. tritici. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2004; 17:484-90. [PMID: 15141952 DOI: 10.1094/mpmi.2004.17.5.484] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
BAX inhibitor-1 (BI-1) proteins have been characterized as suppressors of programmed cell death in mammals and plants. The barley BI-1 is a suppressor of nonspecific background resistance and mlo-mediated penetration resistance to the biotrophic fungal pathogen Blumeria graminis f. sp. hordei when overexpressed in epidermal cells of barley. We report here that BI-1 expression is also slightly up-regulated during interaction with the inappropriate wheat pathogen Blumeria graminis f. sp. tritici. Significantly, overexpression of BI-1 in single epidermal cells of barley by microprojectile-mediated transformation rendered cells susceptible to penetration by inappropriate B. graminis f. sp. tritici. The degree of transgene-induced accessibility to B. graminis f. sp. tritici was thereby similar to the effect achieved by overexpression of the defense suppressor gene Mlo and could not be further enhanced by double expression of both BI-1 and Mlo. Confocal laser scanning microscopy was used to locate a functional green fluorescing GFP:BI-1 fusion protein in endomembranes and the nuclear envelope of barley epidermal cells. Together, enhanced expression of barley BI-1 suppresses penetration resistance to B. graminis f. sp. tritici, linking barley nonhost resistance with cell death regulation.
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Affiliation(s)
- Ruth Eichmann
- Interdisciplinary Research Centre for Environmental Sciences, Institute of Phytopathology and Applied Zoology, Justus-Liebig-University Giessen, Heinrich-Buff Ring 26-32, D-35392 Giessen, Germany
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Schultheiss H, Dechert C, Kogel KH, Hückelhoven R. Functional analysis of barley RAC/ROP G-protein family members in susceptibility to the powdery mildew fungus. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2003; 36:589-601. [PMID: 14617061 DOI: 10.1046/j.1365-313x.2003.01905.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Small monomeric G-proteins of the plant ras (rat sarcome oncogene product) related C3 botulinum toxin substrate (RAC)/Rho of plants (ROP) family are molecular switches in signal transduction of many cellular processes. RAC/ROPs regulate hormone effects, subcellular gradients of Ca2+, the organisation of the actin cytoskeleton and the production of reactive oxygen intermediates. Therefore, we followed a genetic bottom-up strategy to study the role of these proteins during the interaction of barley (Hordeum vulgare L.) with the fungal biotrophic pathogen Blumeria graminis f.sp. hordei (Bgh). We identified six barley RAC/ROP proteins and studied their gene expression. Five out of six Rac/Rop genes were expressed constitutively in the leaf epidermis, which is the site of interaction with Bgh. None of the genes showed enhancement of mRNA abundance after inoculation with Bgh. After microprojectile mediated transformation of single barley epidermal cells with constitutively activated mutant RAC/ROP proteins, we found an RAC/ROP-specific enhancement of pathogen accessibility, tagging HvRACB, HvRAC3 and HvROP6 as host proteins potentially involved in the establishment of susceptibility to Bgh. Confocal laser scanning microscopy (CLSM) of green fluorescent protein (GFP):HvRAC/ROP-transformed cells revealed varying strengths of plasma membrane association of barley RAC/ROPs. The C-terminal CAAX motif for presumable prenylation or the C-terminal hypervariable region (HVR), respectively, were required for membrane association of the RAC/ROPs. Proper intracellular localisation was essential for HvRACB and HvRAC3 function. Together, our data support the view that different paths of host signal transduction via RAC/ROP G-proteins are involved in processes supporting parasitic entry into epidermal host cells.
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Affiliation(s)
- Holger Schultheiss
- Institute of Phytopathology and Applied Zoology, Justus-Liebig-University Giessen, Heinrich-Buff Ring 26-32, D-35392 Giessen, Germany
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Dietrich C, Maiss E. Fluorescent labelling reveals spatial separation of potyvirus populations in mixed infected Nicotiana benthamiana plants. J Gen Virol 2003; 84:2871-2876. [PMID: 13679622 DOI: 10.1099/vir.0.19245-0] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The distribution of potyviruses in mixed infected Nicotiana benthamiana plants was investigated by using green and red fluorescent proteins (GFP, DsRed). Full-length cDNA clones of Plum pox virus (PPV-NAT-AgfpS; PPV-NAT-red), Tobacco vein mottling virus (TVMV-gfp; TVMV-red) and Clover yellow vein virus (ClYVV-GFP) expressing fluorescent proteins, referred to here as labelled viruses, were used to characterize the distribution of different potyviral populations (e.g. TVMV-gfp/PPV-NAT-red), as well as populations of identical, but differently labelled potyviruses (e.g. PPV-NAT-AgfpS/PPV-NAT-red) or in mixed infections of potyviruses with labelled Potato virus X (PVX). Plants infected by any of the PVX/potyvirus combinations exhibited synergistic symptoms and large numbers of cells were doubly infected. In contrast, co-infections of differently labelled potyvirus populations appeared non-synergistic and remained predominantly separate in the infected plants, independent of whether different viruses or identical but differently labelled viruses were co-infecting. Contact of differently labelled virus populations that exhibited spatial separation was restricted to a small number of cells at the border of different fluorescent cell clusters.
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Affiliation(s)
- Christof Dietrich
- Institute of Plant Diseases and Plant Protection, University of Hannover, Herrenhäuser Str. 2, 30419 Hannover, Germany
| | - Edgar Maiss
- Institute of Plant Diseases and Plant Protection, University of Hannover, Herrenhäuser Str. 2, 30419 Hannover, Germany
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Mikkelsen L, Sarrocco S, Lübeck M, Jensen DF. Expression of the red fluorescent protein DsRed-Express in filamentous ascomycete fungi. FEMS Microbiol Lett 2003; 223:135-9. [PMID: 12799012 DOI: 10.1016/s0378-1097(03)00355-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The recently reported red fluorescent protein DsRed from the reef coral Discosoma sp. represents a new marker that has been codon-optimized for high expression in mammalian cells. To facilitate expression of DsRed in ascomycete fungi, we used the clone pDsRed-Express (Clontech) for constructing a plasmid vector, pPgpd-DsRed, containing the constitutive Aspergillus nidulans glyceraldehyde 3-phosphate (gpd) promoter. This vector was used for co-transformation of Penicillium paxilli, Trichoderma harzianum and Trichoderma virens (syn. Gliocladium virens) together with either pAN7-1 or gGFP, both containing a gene for hygromycin resistance for transformant selection. In addition, gGFP contains a green fluorescent protein (GFP) gene for expression in Ascomycetes. Expression of DsRed-Express was obtained in all three fungi, indicating that DsRed can be used as a highly effective vital marker in Ascomycetes. Dual marked transformants expressed both DsRed-Express and GFP in the same mycelium and were used for non-quantitative comparison of the intensity of the fluorescence using confocal laser scanning microscopy.
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Affiliation(s)
- Lisbeth Mikkelsen
- Section of Plant Pathology, Department of Plant Biology, The Royal Veterinary and Agricultural University, 40 Thorvaldsensvej, DK-1871 C, Frederiksberg, Denmark.
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Goodin MM, Dietzgen RG, Schichnes D, Ruzin S, Jackson AO. pGD vectors: versatile tools for the expression of green and red fluorescent protein fusions in agroinfiltrated plant leaves. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2002; 31:375-83. [PMID: 12164816 DOI: 10.1046/j.1365-313x.2002.01360.x] [Citation(s) in RCA: 296] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We have constructed a matched set of binary vectors designated pGD, pGDG and pGDR for the expression and co-localization of native proteins and GFP or DsRed fusions in large numbers of plant cells. The utility of these vectors following agroinfiltration into leaves has been demonstrated with four genes from Sonchus yellow net virus, a plant nucleorhabdovirus, and with a nucleolar marker protein. Of the three SYNV proteins tested, sc4 gave identical localization patterns at the cell wall and nucleus when fused to GFP or DsRed. However, some differences in expression patterns were observed depending on whether DsRed or GFP was the fusion partner. In this regard, the DsRed:P fusion showed a similar pattern of localization to GFP:P, but localized foci appeared in the nucleus and near the periphery of the nucleus. Nevertheless, the viral nucleocapsid protein, expressed as a GFP:N fusion, co-localized with DsRed:P in a subnuclear locale in agreement with our previous observations (Goodin et al., 2001). This locale appears to be distinct from the nucleolus as indicated by co-expression of the N protein, DsRed:P and a nucleolar marker AtFib1 fused to GFP. The SYNV M protein, which is believed to be particularly prone to oligomerization, was detectable only as a GFP fusion. Our results indicate that agroinfiltration with bacteria containing the pGD vectors is extremely useful for transient expression of several proteins in a high proportion of the cells of Nicotiana benthamiana leaves. The GFP and DsRed elements incorporated into the pGD system should greatly increase the ease of visualizing co-localization and interactions of proteins in a variety of experimental dicotyledonous hosts.
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Affiliation(s)
- Michael M Goodin
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
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