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Recent Advances in Antibiotic-Free Markers; Novel Technologies to Enhance Safe Human Food Production in the World. Mol Biotechnol 2022:10.1007/s12033-022-00609-7. [DOI: 10.1007/s12033-022-00609-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/07/2022] [Indexed: 11/30/2022]
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Characterization of Agrobacterium-mediated co-transformation events in rice using green and red fluorescent proteins. Mol Biol Rep 2022; 49:9613-9622. [PMID: 36040546 DOI: 10.1007/s11033-022-07864-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 08/11/2022] [Indexed: 10/14/2022]
Abstract
BACKGROUND Biotechnologists seeking to develop marker-free transgenic plants have established co-transformation methods. For co-transformation using mixed Agrobacterium strains, the mix ratio of Agrobacterium strains and selection scheme may influence co-transformation frequency. This study used fluorescent GFP and RFP markers to compose different selection schemes for observation of the selective dynamics of transformed rice cells and to investigate the factors affecting co-transformation efficiency. METHODS AND RESULTS We utilized GFP and RFP markers in co-transformation and tested the combinations of an antibiotic-selectable vector (pGFP-HPT) and a single RFP vector (pRFP) and of two antibiotic-selectable vectors (pGFP-HPT and pRFP-HPT) in rice. The pGFP-HPT/pRFP combination resulted in 70.9% to 81.2% of co-transformation frequencies while lower frequencies (56.6% on average) were obtained with the pGFP-HPT/pRFP-HPT combination. Based on GFP/RFP segregation patterns, 55% of the pGFP-HPT/pRFP co-transformants contained unlinked T-DNAs and segregated single RFP progeny, which simulated the selection process of marker-free transgenic plants that carry an actual gene of interest. Transgene expression levels in the rice lines varied as revealed by RT-PCR, and tandem-linked T-DNAs were detected in co-transformants, suggesting that transgene expression might be affected by duplicated T-DNA structures. CONCLUSION Co-transformation via mixed Agrobacterium strains is feasible, and approximately 55% of the pGFP-HPT/pRFP co-transformants contained unlinked T-DNAs and segregated single RFP progeny. The pGFP-HPT/pRFP and the pGFP-HPT/pRFP-HPT vector combinations showed distinctive selective dynamics of transformed rice cells, suggesting that co-transformation efficiency depends on both vector system and selection scheme.
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Jansing J, Schiermeyer A, Schillberg S, Fischer R, Bortesi L. Genome Editing in Agriculture: Technical and Practical Considerations. Int J Mol Sci 2019; 20:E2888. [PMID: 31200517 PMCID: PMC6627516 DOI: 10.3390/ijms20122888] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 05/29/2019] [Accepted: 06/06/2019] [Indexed: 01/31/2023] Open
Abstract
The advent of precise genome-editing tools has revolutionized the way we create new plant varieties. Three groups of tools are now available, classified according to their mechanism of action: Programmable sequence-specific nucleases, base-editing enzymes, and oligonucleotides. The corresponding techniques not only lead to different outcomes, but also have implications for the public acceptance and regulatory approval of genome-edited plants. Despite the high efficiency and precision of the tools, there are still major bottlenecks in the generation of new and improved varieties, including the efficient delivery of the genome-editing reagents, the selection of desired events, and the regeneration of intact plants. In this review, we evaluate current delivery and regeneration methods, discuss their suitability for important crop species, and consider the practical aspects of applying the different genome-editing techniques in agriculture.
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Affiliation(s)
- Julia Jansing
- Aachen-Maastricht Institute for Biobased Materials (AMIBM), Maastricht University, Brightlands Chemelot Campus, Urmonderbaan 22, 6167 RD Geleen, The Netherlands.
| | - Andreas Schiermeyer
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Forckenbeckstrasse 6, 52074 Aachen, Germany.
| | - Stefan Schillberg
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Forckenbeckstrasse 6, 52074 Aachen, Germany.
| | - Rainer Fischer
- Indiana Biosciences Research Institute (IBRI), 1345 W. 16th St. Suite 300, Indianapolis, IN 46202, USA.
| | - Luisa Bortesi
- Aachen-Maastricht Institute for Biobased Materials (AMIBM), Maastricht University, Brightlands Chemelot Campus, Urmonderbaan 22, 6167 RD Geleen, The Netherlands.
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Dutt M, Zambon FT, Erpen L, Soriano L, Grosser J. Embryo-specific expression of a visual reporter gene as a selection system for citrus transformation. PLoS One 2018; 13:e0190413. [PMID: 29293649 PMCID: PMC5749800 DOI: 10.1371/journal.pone.0190413] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 12/14/2017] [Indexed: 01/18/2023] Open
Abstract
The embryo-specific Dc3 gene promoter driving the VvMybA1 anthocyanin regulatory gene was used to develop a visual selection system for the genetic transformation of citrus. Agrobacterium-mediated transformation of cell suspension cultures resulted in the production of purple transgenic somatic embryos that could be easily separated from the green non-transgenic embryos. The somatic embryos produced phenotypically normal plants devoid of any visual purple coloration. These results were also confirmed using protoplast transformation. There was minimal gene expression in unstressed one-year-old transgenic lines. Cold and drought stress did not have any effect on gene expression, while exogenous ABA and NaCl application resulted in a minor change in gene expression in several transgenic lines. When gas exchange was measured in intact leaves, the transgenic lines were similar to controls under the same environment. Our results provide conclusive evidence for the utilization of a plant-derived, embryo-specific visual reporter system for the genetic transformation of citrus. Such a system could aid in the development of an all-plant, consumer-friendly GM citrus tree.
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Affiliation(s)
- Manjul Dutt
- Citrus Research and Education Center, University of Florida, Lake Alfred, Florida, United States of America
- * E-mail:
| | - Flavia T. Zambon
- Citrus Research and Education Center, University of Florida, Lake Alfred, Florida, United States of America
| | - Lígia Erpen
- Citrus Research and Education Center, University of Florida, Lake Alfred, Florida, United States of America
- Universidade de São Paulo, Escola Superior de Agricultura Luiz de Queiroz, Piracicaba, São Paulo, Brazil
| | - Leonardo Soriano
- Universidade de São Paulo, Escola Superior de Agricultura Luiz de Queiroz, Piracicaba, São Paulo, Brazil
| | - Jude Grosser
- Citrus Research and Education Center, University of Florida, Lake Alfred, Florida, United States of America
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Ahmed MMS, Bian S, Wang M, Zhao J, Zhang B, Liu Q, Zhang C, Tang S, Gu M, Yu H. RNAi-mediated resistance to rice black-streaked dwarf virus in transgenic rice. Transgenic Res 2016; 26:197-207. [PMID: 27900537 DOI: 10.1007/s11248-016-9999-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 11/13/2016] [Indexed: 10/20/2022]
Abstract
Rice black-streaked dwarf virus (RBSDV), a member of the genus Fijivirus in the family Reoviridae, causes significant economic losses in rice production in China and many other Asian countries. Development of resistant varieties by using conventional breeding methods is limited, as germplasm with high level of resistance to RBSDV have not yet been found. One of the most promising methods to confer resistance against RBSDV is the use of RNA interference (RNAi) technology. RBSDV non-structural protein P7-2, encoded by S7-2 gene, is a potential F-box protein and involved in the plant-virus interaction through the ubiquitination pathway. P8, encoded by S8 gene, is the minor core protein that possesses potent active transcriptional repression activity. In this study, we transformed rice calli using a mini-twin T-DNA vector harboring RNAi constructs of the RBSDV genes S7-2 or S8, and obtained plants harboring the target gene constructs and the selectable marker gene, hygromycin phosphotransferase (HPT). From the offspring of these transgenic plants, we obtained selectable marker (HPT gene)-free plants. Homozygous T5 transgenic lines which harbored either S7-2-RNAi or S8-RNAi exhibited high level resistance against RBSDV under field infection pressure from indigenous viruliferous small brown planthoppers. Thus, our results showed that RNA interference with the expression of S7-2 or S8 genes seemed an effective way to induce high level resistance in rice against RBSD disease.
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Affiliation(s)
- Mohamed M S Ahmed
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, 225009, China.,Department of Crop Protection, Faculty of Agriculture, University of Khartoum, 13314, Khartoum North, Sudan
| | - Shiquan Bian
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, 225009, China
| | - Muyue Wang
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, 225009, China
| | - Jing Zhao
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, 225009, China
| | - Bingwei Zhang
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, 225009, China
| | - Qiaoquan Liu
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, 225009, China
| | - Changquan Zhang
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, 225009, China
| | - Shuzhu Tang
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, 225009, China
| | - Minghong Gu
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, 225009, China
| | - Hengxiu Yu
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, 225009, China.
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HAMZEH S, MOTALLEBI M, ZAMANI MR. Efficient seed-specifically regulated autoexcision of marker gene (nptII) with inducible expression of interest gene in transgenic Nicotiana tabacum. Turk J Biol 2016. [DOI: 10.3906/biy-1408-32] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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Matheka JM, Anami S, Gethi J, Omer RA, Alakonya A, Machuka J, Runo S. A new double right border binary vector for producing marker-free transgenic plants. BMC Res Notes 2013; 6:448. [PMID: 24207020 PMCID: PMC3829385 DOI: 10.1186/1756-0500-6-448] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 11/05/2013] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Once a transgenic plant is developed, the selectable marker gene (SMG) becomes unnecessary in the plant. In fact, the continued presence of the SMG in the transgenic plant may cause unexpected pleiotropic effects as well as environmental or biosafety issues. Several methods for removal of SMGs that have been reported remain inaccessible due to protection by patents, while development of new ones is expensive and cost prohibitive. Here, we describe the development of a new vector for producing marker-free plants by simply adapting an ordinary binary vector to the double right border (DRB) vector design using conventional cloning procedures. FINDINGS We developed the DRB vector pMarkfree5.0 by placing the bar gene (representing genes of interest) between two copies of T-DNA right border sequences. The β-glucuronidase (gus) and nptII genes (representing the selectable marker gene) were cloned next followed by one copy of the left border sequence. When tested in a model species (tobacco), this vector system enabled the generation of 55.6% kanamycin-resistant plants by Agrobacterium-mediated transformation. The frequency of cotransformation of the nptII and bar transgenes using the vector was 66.7%. Using the leaf bleach and Basta assays, we confirmed that the nptII and bar transgenes were coexpressed and segregated independently in the transgenic plants. This enable separation of the transgenes in plants cotransformed using pMarkfree5.0. CONCLUSIONS The results suggest that the DRB system developed here is a practical and effective approach for separation of gene(s) of interest from a SMG and production of SMG-free plants. Therefore this system could be instrumental in production of "clean" plants containing genes of agronomic importance.
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Affiliation(s)
- Jonathan M Matheka
- Biochemistry and Biotechnology Department, Kenyatta University, P. O. Box 43844, 00100 Nairobi, Kenya
| | - Sylvester Anami
- Institute for Biotechnology Research, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000–00100, Nairobi, Kenya
| | - James Gethi
- Kenya Agricultural Research Institute, P.O. Box 340–90100, Machakos, Kenya
| | - Rasha A Omer
- Biosafety and Biotechnology Research Center, Agricultural Research Corporation, P.O. Box 126, Wad Medani, Sudan
| | - Amos Alakonya
- Institute for Biotechnology Research, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000–00100, Nairobi, Kenya
| | - Jesse Machuka
- Biochemistry and Biotechnology Department, Kenyatta University, P. O. Box 43844, 00100 Nairobi, Kenya
| | - Steven Runo
- Biochemistry and Biotechnology Department, Kenyatta University, P. O. Box 43844, 00100 Nairobi, Kenya
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An efficient method for organic acetylation and use of dl-phosphinothricin as a negative selection agent in argE transgenic rice. Biochem Biophys Res Commun 2013; 441:243-8. [DOI: 10.1016/j.bbrc.2013.10.048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 10/10/2013] [Indexed: 11/21/2022]
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9
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Yau YY, Stewart CN. Less is more: strategies to remove marker genes from transgenic plants. BMC Biotechnol 2013; 13:36. [PMID: 23617583 PMCID: PMC3689633 DOI: 10.1186/1472-6750-13-36] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 03/05/2013] [Indexed: 02/07/2023] Open
Abstract
Selectable marker genes (SMGs) and selection agents are useful tools in the production of transgenic plants by selecting transformed cells from a matrix consisting of mostly untransformed cells. Most SMGs express protein products that confer antibiotic- or herbicide resistance traits, and typically reside in the end product of genetically-modified (GM) plants. The presence of these genes in GM plants, and subsequently in food, feed and the environment, are of concern and subject to special government regulation in many countries. The presence of SMGs in GM plants might also, in some cases, result in a metabolic burden for the host plants. Their use also prevents the re-use of the same SMG when a second transformation scheme is needed to be performed on the transgenic host. In recent years, several strategies have been developed to remove SMGs from GM products while retaining the transgenes of interest. This review describes the existing strategies for SMG removal, including the implementation of site specific recombination systems, TALENs and ZFNs. This review discusses the advantages and disadvantages of existing SMG-removal strategies and explores possible future research directions for SMG removal including emerging technologies for increased precision for genome modification.
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Affiliation(s)
- Yuan-Yeu Yau
- Department of Natural Sciences, Northeastern State University, Broken Arrow, OK 74014, USA
| | - C Neal Stewart
- Department of Plant Sciences, University of Tennessee, Knoxville, TN 37996, USA
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Bie X, Wang K, She M, Du L, Zhang S, Li J, Gao X, Lin Z, Ye X. Combinational transformation of three wheat genes encoding fructan biosynthesis enzymes confers increased fructan content and tolerance to abiotic stresses in tobacco. PLANT CELL REPORTS 2012; 31:2229-38. [PMID: 22911265 DOI: 10.1007/s00299-012-1332-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 08/01/2012] [Accepted: 08/02/2012] [Indexed: 05/21/2023]
Abstract
KEY MESSAGE Seven kinds of transgenic tobacco plants transformed with combinations of three FBE genes were obtained. The transgenic plants transformed with Ta1-SST + Ta6-SFT genes appeared to have the highest fructan or soluble sugar content and the strongest salt tolerance. Fructan is thought to be one of the important regulators involved in plant tolerance to various abiotic stresses. In this study, wheat-derived genes, Ta1-SST, Ta6-SFT, and Ta1-FFT, encoding fructan biosynthesis enzymes (FBE) were isolated and cloned into vectors modified pBI121 or pZP211. Seven different combinations of the three target genes were transformed into tobacco plants through an Agrobacterium-mediated approach, and transgenic tobacco plants were identified by PCR, ELISA, and Southern blotting. Compared with tobacco plants transformed with other six combinations of the three target genes and with wild-type plants, the transgenic plants transformed with Ta1-SST + Ta6-SFT genes contained the highest fructan and soluble sugar content. All seven types of transgenic tobacco plants displayed a much higher level of tolerance to drought, low temperature, and high salinity compared with the wild type. Differences of drought and low temperature tolerance between the transgenic plants containing a single FBE gene and those harboring two or three FBE genes were not significant, but the salt tolerance level of the transgenic plants with different FBE gene combinations from high to low was: Ta1-SST + Ta6-SFT > Ta1-SST + Ta6-SFT + Ta1-FFT > Ta1-SST + Ta1-FFT > Ta1-SFT + Ta1-FFT > single FBE gene. These results indicated that the tolerances of the transgenic tobacco plants to various abiotic stresses were associated with the transformed target gene combinations and the contents of fructan and soluble sugar contained in the transgenic plants.
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Affiliation(s)
- Xiaomin Bie
- National Key Facility of Crop Gene Resources and Genetic Improvement/Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China
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Mehrotra S, Goyal V. Agrobacterium-mediated gene transfer in plants and biosafety considerations. Appl Biochem Biotechnol 2012; 168:1953-75. [PMID: 23090683 DOI: 10.1007/s12010-012-9910-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 10/03/2012] [Indexed: 12/21/2022]
Abstract
Agrobacterium, the natures' genetic engineer, has been used as a vector to create transgenic plants. Agrobacterium-mediated gene transfer in plants is a highly efficient transformation process which is governed by various factors including genotype of the host plant, explant, vector, plasmid, bacterial strain, composition of culture medium, tissue damage, and temperature of co-cultivation. Agrobacterium has been successfully used to transform various economically and horticulturally important monocot and dicot species by standard tissue culture and in planta transformation techniques like floral or seedling infilteration, apical meristem transformation, and the pistil drip methods. Monocots have been comparatively difficult to transform by Agrobacterium. However, successful transformations have been reported in the last few years based on the adjustment of the parameters that govern the responses of monocots to Agrobacterium. A novel Agrobacterium transferred DNA-derived nanocomplex method has been developed which will be highly valuable for plant biology and biotechnology. Agrobacterium-mediated genetic transformation is known to be the preferred method of creating transgenic plants from a commercial and biosafety perspective. Agrobacterium-mediated gene transfer predominantly results in the integration of foreign genes at a single locus in the host plant, without associated vector backbone and is also known to produce marker free plants, which are the prerequisites for commercialization of transgenic crops. Research in Agrobacterium-mediated transformation can provide new and novel insights into the understanding of the regulatory process controlling molecular, cellular, biochemical, physiological, and developmental processes occurring during Agrobacterium-mediated transformation and also into a wide range of aspects on biological safety of transgenic crops to improve crop production to meet the demands of ever-growing world's population.
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Affiliation(s)
- Shweta Mehrotra
- National Research Centre on Plant Biotechnology, Lal Bahadur Shastri Building, Pusa Campus, New Delhi 110012, India.
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Tuteja N, Verma S, Sahoo RK, Raveendar S, Reddy INBL. Recent advances in development of marker-free transgenic plants: Regulation and biosafety concern. J Biosci 2012; 37:167-97. [PMID: 22357214 DOI: 10.1007/s12038-012-9187-5] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Narendra Tuteja
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India.
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Dutt M, Li ZT, Dhekney SA, Gray DJ. Co-transformation of grapevine somatic embryos to produce transgenic plants free of marker genes. Methods Mol Biol 2012; 847:201-213. [PMID: 22351010 DOI: 10.1007/978-1-61779-558-9_17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A cotransformation system using somatic embryos was developed to produce grapevines free of selectable marker genes. This was achieved by transforming Vitis vinifera L. "Thompson Seedless" somatic embryos with a mixture of two Agrobacterium strains. The first strain contained a binary plasmid with an egfp gene of interest between the T-DNA borders. The second strain harbored the neomycin phosphotransferase (nptII) gene for positive selection and the cytosine deaminase (codA) gene for negative selection, linked together by a bidirectional dual promoter complex. Our technique included a short positive selection phase of cotransformed somatic embryos on liquid medium containing 100 mg/L kanamycin before subjecting cultures to prolonged negative selection on medium containing 250 mg/L 5-fluorocytosine.
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Affiliation(s)
- Manjul Dutt
- Citrus Research and Education Center, University of Florida/IFAS, Lake Alfred, FL, USA
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Ferradini N, Nicolia A, Capomaccio S, Veronesi F, Rosellini D. Assessment of simple marker-free genetic transformation techniques in alfalfa. PLANT CELL REPORTS 2011; 30:1991-2000. [PMID: 21691741 DOI: 10.1007/s00299-011-1107-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 05/05/2011] [Accepted: 06/04/2011] [Indexed: 05/30/2023]
Abstract
Methods to avoid the presence of selectable marker genes (SMG) in transgenic plants are available but not implemented in many crop species. We assessed the efficiency of simple marker-free Agrobacterium-mediated transformation techniques in alfalfa: regeneration without selection, or marker-less, and co-transformation with two vectors, one containing the SMG and one containing a non-selected gene. To easily estimate the efficiency of marker-less transformation, the nptII and the GUS markers were used as non-selected genes. After Agrobacterium treatment, somatic embryos were regenerated without selection. The percentage of transgenic embryos was determined by a second cycle of regeneration using the embryos as starting material, in the presence of kanamycin, by PCR screening of T1 progenies, and by the GUS test. In two experiments, from 0 to 1.7% of the somatic embryos were transgenic. Co-transformation was performed with two vectors, one with the hemL SMG and one with the unselected nptII gene, each carried by a different culture of Agrobacterium. Only 15 putative co-transformed plants were regenerated from two experiments, with an average co-transformation percentage of 3.7. Southern blot hybridizations and/or T(1) progeny segregation were used to confirm transgene integration, and qPCR was also used to estimate the T-DNA copy number. In the T(1) progenies obtained by crossing with a non-transgenic pollinator, marker-free segregants were obtained. Both marker-free approaches showed very low efficiency.
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Affiliation(s)
- Nicoletta Ferradini
- Dipartimento di Biologia Applicata, Università degli Studi di Perugia, Borgo XX giugno 74, 06121, Perugia, Italy
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Sripriya R, Sangeetha M, Parameswari C, Veluthambi B, Veluthambi K. Improved Agrobacterium-mediated co-transformation and selectable marker elimination in transgenic rice by using a high copy number pBin19-derived binary vector. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2011; 180:766-74. [PMID: 21497712 DOI: 10.1016/j.plantsci.2011.02.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2010] [Revised: 02/17/2011] [Accepted: 02/22/2011] [Indexed: 05/30/2023]
Abstract
A high copy number, selectable marker gene (SMG)-free Agrobacterium binary vector pBin19ΔnptII was constructed by deleting the nptII gene from pBin19. The binary vectors with the RK2 and pVS replication origins exist in 12 and 3 copies, respectively, in Agrobacterium. The tobacco osmotin gene (ap24) was cloned in pBin19ΔnptII and the resultant plasmid pBin19ΔnptII-ap24 was mobilized into the Agrobacterium tumefaciens strain C58C1 Rif(r) harbouring the single-copy cointegrate vector pGV2260::pSSJ1. The T-DNA of the cointegrate vector harboured the hph (SMG) and gus genes. Transformation of Oryza sativa L. var. Pusa Basmati1 with Agrobacterium tumefaciens (pGV2260::pSSJ1, pBin19ΔnptII-ap24) yielded 14 independent hyg+/GUS+ transgenic plants. Southern blot analysis with hph and ap24 probes revealed that 12 out of the 14 transgenic plants were co-transformed and harboured hph, gus and ap24 genes. The new multi-copy binary vector yielded 86% co-transformation efficiency. SMG elimination by genetic separation of the cointegrate T-DNA with the hph/gus genes and binary vector T-DNA with the ap24 gene was accomplished in four out of ten primary co-transformants that were forwarded to the T₁ generation.
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Affiliation(s)
- Rajasekaran Sripriya
- Department of Plant Biotechnology, School of Biotechnology, Madurai Kamaraj University, Palkalai Nagar, Madurai 625021, Tamil Nadu, India
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RamanaRao MV, Veluthambi K. Selectable marker elimination in the T0 generation by Agrobacterium-mediated co-transformation involving Mungbean yellow mosaic virus TrAP as a non-conditional negative selectable marker and bar for transient positive selection. PLANT CELL REPORTS 2010; 29:473-83. [PMID: 20204372 DOI: 10.1007/s00299-010-0836-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Revised: 01/15/2010] [Accepted: 02/15/2010] [Indexed: 05/28/2023]
Abstract
Transient selection involving the bar gene and non-conditional negative selection against stable T-DNA integration through the use of the Mungbean yellow mosaic virus (MYMV) transcriptional activator protein gene (TrAP) were used in a novel co-transformation strategy to generate selectable marker gene (SMG)-eliminated transgenic tobacco plants in the T(0) generation itself. Two compatible binary plasmids, pCam-bar-TrAP-gus harbouring bar as an SMG and the MYMV TrAP gene as a non-conditional negative selectable marker, and pGA472 with the nptII gene as an unselected experimental gene of interest (GOI) were placed in the Agrobacterium tumefaciens strain EHA105 and used for co-transformation. Transient selection with 5 mg l(-1) phosphinothricin (PPT) for 2-4 weeks and subsequent establishment in a PPT-minus medium yielded 114 plants from 200 leaf discs. The unselected nptII gene was detected by Southern blot analysis in 13 plants, revealing a co-transformation efficiency of 11.5%. Five of these plants harboured only the nptII gene (GOI) and not the bar gene (SMG). Thus, SMG elimination was achieved in the T(0) generation itself in 4.4% (5/114) of plants, which were transiently selected for 2-4 weeks on PPT. MYMV TrAP, a non-conditional negative selectable marker, effectively reduced the recovery of plants with stable integration of the SMG (bar).
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Affiliation(s)
- Mangu Venkata RamanaRao
- Department of Plant Biotechnology, School of Biotechnology, Madurai Kamaraj University, Madurai, Tamil Nadu, India
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Song GQ, Sink KC, Ma Y, Herlache T, Hancock JF, Loescher WH. A novel mannose-based selection system for plant transformation using celery mannose-6-phosphate reductase gene. PLANT CELL REPORTS 2010; 29:163-72. [PMID: 20033814 DOI: 10.1007/s00299-009-0809-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 12/07/2009] [Accepted: 12/08/2009] [Indexed: 05/28/2023]
Abstract
To investigate its potential application as a selectable marker for plant transformation, the mannitol producing, celery mannose-6-phosphate reductase gene (M6PR) was transformed into Arabidopsis and tobacco using Agrobacterium tumefaciens-mediated transformation. Mannose-tolerance assays in transgenic materials revealed that the M6PR can act as a selectable marker gene in either a positive or a negative selection mode depending on the plant species. For mannose sensitive species, such as Arabidopsis, expression of M6PR enhanced mannose tolerance and provided a positive selection for transgenic seeds. On medium containing 2 g/L mannose, transgenic seeds germinated, whereas wild type (WT) seeds did not. For mannose-tolerant species, expression of M6PR increased mannose sensitivity in tobacco and enabled a negative selection for transgenic leaves and seeds. Mannose at 30 g/L blanched leaf explants from all 29 transgenic tobacco events with M6PR. In contrast, 30 g/L mannose did not inhibit shoot regeneration from leaf explants of WT or transgenic plants with either an antisense M6PR or a plasmid control. Similarly, mannose at 30 g/L inhibited seed germination of transgenic tobacco seeds with M6PR but not that of WT or transgenic tobacco with either the antisense M6PR or the plasmid control. Northern blot confirmed transcripts of the M6PR in transgenic tobacco, and accumulation of mannitol verified activity of the M6PR in tobacco leaves. Either positive or negative selection using the celery M6PR is versatile for plant transformation. Additionally, the celery M6PR is a potential target gene for improving salt-tolerance in plants due to mannitol accumulation.
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Affiliation(s)
- Guo-Qing Song
- Plant Biotechnology Resource and Outreach Center, Department of Horticulture, Michigan State University, East Lansing, MI 48824, USA
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Li F, Wu S, Lü F, Chen T, Ju M, Wang H, Jiang Y, Zhang J, Guo W, Zhang T. Modified fiber qualities of the transgenic cotton expressing a silkworm fibroin gene. Sci Bull (Beijing) 2009. [DOI: 10.1007/s11434-009-0142-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Sripriya R, Raghupathy V, Veluthambi K. Generation of selectable marker-free sheath blight resistant transgenic rice plants by efficient co-transformation of a cointegrate vector T-DNA and a binary vector T-DNA in one Agrobacterium tumefaciens strain. PLANT CELL REPORTS 2008; 27:1635-1644. [PMID: 18663452 DOI: 10.1007/s00299-008-0586-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Revised: 07/03/2008] [Accepted: 07/08/2008] [Indexed: 05/26/2023]
Abstract
Co-transformation of Oryza sativa L. var. Pusa Basmati1 was done using an Agrobacterium tumefaciens strain harbouring a single-copy cointegrate vector and a multi-copy binary vector in the same cell. The T-DNA of the cointegrate vector pGV2260::pSSJ1 carried the hygromycin phosphotransferase (hph) and beta-glucuronidase (gus) genes. The binary vector pCam-chi11, without a plant selectable marker gene, harboured the rice chitinase (chi11) gene under maize ubiquitin promoter. Co-transformation of the gene of interest (chi11) with the selectable marker gene (hph) occurred in 4 out of 20 T(0) plants (20%). Segregation of hph from chi11 was accomplished in two (CoT6 and CoT23) of the four co-transformed plants in the T(1) generation. The selectable marker-free (SMF) lines CoT6 and CoT23 harboured single copies of chi11. Homozygous SMF T(2) plants were established in the lines CoT6 and CoT23. Northern and Western blot analysis of the homozygous SMF lines showed high level of transgene expression. In comparison to untransformed controls, chitinase specific activity was 66- and 22-fold higher in the homozygous SMF T(2) plants of lines CoT6 and CoT23, respectively. The lines CoT6 and CoT23 exhibited 38 and 40% reduction in sheath blight disease, respectively.
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Affiliation(s)
- Rajasekaran Sripriya
- Department of Plant Biotechnology, School of Biotechnology, Madurai Kamaraj University, Madurai 625021, Tamil Nadu, India
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Homrich MS, Passaglia LMP, Pereira JF, Bertagnolli PF, Pasquali G, Zaidi MA, Altosaar I, Bodanese-Zanettini MH. Resistance to Anticarsia gemmatalis Hübner (Lepidoptera, Noctuidae) in transgenic soybean (Glycine max (L.) Merrill Fabales, Fabaceae) cultivar IAS5 expressing a modified Cry1Ac endotoxin. Genet Mol Biol 2008. [DOI: 10.1590/s1415-47572008000300020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Seong ES, Guo J, Kim YH, Cho JH, Lim CK, Hyun Hur J, Wang MH. Regulations of marker genes involved in biotic and abiotic stress by overexpression of the AtNDPK2 gene in rice. Biochem Biophys Res Commun 2007; 363:126-32. [PMID: 17826739 DOI: 10.1016/j.bbrc.2007.08.147] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2007] [Accepted: 08/20/2007] [Indexed: 02/02/2023]
Abstract
AtNDPK2 is involved in transcriptional regulation in response to pathogen and abiotic stresses. AtNDPK2-expressing transgenic rice plants showed regulation of the marker genes for chilling and oxidative stresses. In the present study, we produced AtNDPK2-overexpressing transgenic rice lines using the co-transformation method. Morphologically, the transgenic plants, compared with the control plants, were growth retarded. We investigated how AtNDPK2 overexpression influences the response of rice plants to marker genes related to chilling and ROS stress. The accumulation of transcripts of pBC442 and pBC601, related to chilling stress, was induced in AtNDPK2-overexpressed rice plants. On further investigation, we found that OsAPX1-, OsAPX2-, and OsSodB-scavenging free-oxygen radicals, such as superoxide (O2-) and hydrogen peroxide (H(2)O(2)), could be induced in AtNDPK2-overexpressed rice plants. In particular, transcripts encoding pathogenesis-related (PR) proteins OsPR2 and OsPR4, as well as oxidative stress response proteins, were confirmed to change the gene expression in the transgenic rice plants. Together, these results suggest that AtNDPK2 plays a regulatory role in chilling and antioxidant signaling in plants.
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Affiliation(s)
- Eun Soo Seong
- School of Biotechnology, Kangwon National University, Chuncheon, Kangwon-do 200-701, South Korea
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Arumugam N, Gupta V, Jagannath A, Mukhopadhyay A, Pradhan AK, Burma PK, Pental D. A passage through in vitro culture leads to efficient production of marker-free transgenic plants in Brassica juncea using the Cre-loxP system. Transgenic Res 2007; 16:703-12. [PMID: 17219247 DOI: 10.1007/s11248-006-9058-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Accepted: 11/20/2006] [Indexed: 11/30/2022]
Abstract
The Cre-loxP site-specific recombination system was deployed for removal of marker genes from Brassica juncea (Indian mustard). Excision frequencies, monitored by removal of nptII or gfp genes in F(1) plants of crosses between LOX and CRE lines, were high in quiescent, differentiated somatic tissues but extremely poor in the meristematic regions (and consequently the germinal cells) thus preventing identification and selection of marker-free transgenic events which are devoid of both the marker gene as well as the cre gene, in F(2) progeny. We show that a passage through in vitro culture of F(1 )leaf explants allows efficient development of marker-free transgenics in the F(2) generation addressing current limitations associated with efficient use of the Cre/loxP technology for marker gene removal.
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Affiliation(s)
- N Arumugam
- Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India
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Abstract
Selectable marker genes (SMGs) have been extraordinarily useful in enabling plant transformation because of the low efficiency of transgene integration. The most used SMGs encode proteins resistant to antibiotics or herbicides and use negative selection, i.e., by killing nontransgenic tissue. However, there are perceived risks in wide-scale deployment of SMG-transgenic plants, and therefore research has recently been performed to develop marker-free systems. In this review, transformation using markers not based on antibiotic or herbicide resistance genes, as well as different systems of marker gene deletion, are discussed.
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Affiliation(s)
- Behrooz Darbani
- Agriculture Biotechnology Research Institute for Northwest & West of Iran, Tabriz, Iran
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