401
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Transcriptional and post-transcriptional enhancement of gene expression by the 5' UTR intron of rice rubi3 gene in transgenic rice cells. Mol Genet Genomics 2008; 279:429-39. [PMID: 18236078 DOI: 10.1007/s00438-008-0323-8] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Accepted: 01/13/2008] [Indexed: 01/01/2023]
Abstract
Introns play a very important role in regulating gene expression in eukaryotes. In plants, many introns enhance gene expression, and the effect of intron-mediated enhancement (IME) of gene expression is reportedly often more profound in monocots than in dicots. To further gain insight of IME in monocot plants, we quantitatively dissected the effect of the 5' UTR intron of the rice rubi3 gene at various gene expression levels in stably transformed suspension cell lines. The intron enhanced the GUS reporter gene activity in these lines by about 29-fold. Nuclear run-on experiments demonstrated a nearly twofold enhancement by the 5' UTR intron at the transcriptional level. RNA analysis by RealTime quantitative RT-PCR assays indicated the intron enhanced the steady state RNA level of the GUS reporter gene by nearly 20-fold, implying a strong role of the intron in RNA processing and/or export. The results also implicated a moderate role of the intron in enhancement at the translational level ( approximately 45%). Moreover, results from a transient assay experiment using a shortened exon 1 sequence revealed an important role of exon 1 of rubi3 in gene expression. It may also hint a divergence in IME mechanisms between plant and animal cells. These results demonstrated transcriptional enhancement by a plant intron, but suggested that post-transcriptional event(s) be the major source of IME.
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402
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Qu S, Desai A, Wing R, Sundaresan V. A versatile transposon-based activation tag vector system for functional genomics in cereals and other monocot plants. PLANT PHYSIOLOGY 2008; 146:189-99. [PMID: 17993541 PMCID: PMC2230568 DOI: 10.1104/pp.107.111427] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Accepted: 10/30/2007] [Indexed: 05/19/2023]
Abstract
Transposon insertional mutagenesis is an effective alternative to T-DNA mutagenesis when transformation through tissue culture is inefficient as is the case for many crop species. When used as activation tags, transposons can be exploited to generate novel gain-of-function phenotypes without transformation and are of particular value in the study of polyploid plants where gene knockouts will not have phenotypes. We have developed an in cis-activation-tagging Ac-Ds transposon system in which a T-DNA vector carries a Dissociation (Ds) element containing 4x cauliflower mosaic virus enhancers along with the Activator (Ac) transposase gene. Stable Ds insertions were selected using green fluorescent protein and red fluorescent protein genes driven by promoters that are functional in maize (Zea mays) and rice (Oryza sativa). The system has been tested in rice, where 638 stable Ds insertions were selected from an initial set of 26 primary transformants. By analysis of 311 flanking sequences mapped to the rice genome, we could demonstrate the wide distribution of the elements over the rice chromosomes. Enhanced expression of rice genes adjacent to Ds insertions was detected in the insertion lines using semiquantitative reverse transcription-PCR method. The in cis-two-element vector system requires minimal number of primary transformants and eliminates the need for crossing, while the use of fluorescent markers instead of antibiotic or herbicide resistance increases the applicability to other plants and eliminates problems with escapes. Because Ac-Ds has been shown to transpose widely in the plant kingdom, the activation vector system developed in this study should be of utility more generally to other monocots.
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Affiliation(s)
- Shaohong Qu
- Section of Plant Biology , University of California, Davis, CA 95616, USA
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403
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Chapter 3: Double-Embryo, High-Protein, High-Oil Maize Produced Using a Cytokinin-Based Flower Rescue. Compr Rev Food Sci Food Saf 2008. [DOI: 10.1111/j.1541-4337.2007.00029_5.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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404
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Joensuu JJ, Niklander-Teeri V, Brandle JE. Transgenic plants for animal health: plant-made vaccine antigens for animal infectious disease control. PHYTOCHEMISTRY REVIEWS : PROCEEDINGS OF THE PHYTOCHEMICAL SOCIETY OF EUROPE 2008; 7:553-577. [PMID: 32214922 PMCID: PMC7089046 DOI: 10.1007/s11101-008-9088-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2007] [Accepted: 02/05/2008] [Indexed: 05/19/2023]
Abstract
A variety of plant species have been genetically modified to accumulate vaccine antigens for human and animal health and the first vaccine candidates are approaching the market. The regulatory burden for animal vaccines is less than that for human use and this has attracted the attention of researchers and companies, and investment in plant-made vaccines for animal infectious disease control is increasing. The dosage cost of vaccines for animal infectious diseases must be kept to a minimum, especially for non-lethal diseases that diminish animal welfare and growth, so efficient and economic production, storage and delivery are critical for commercialization. It has become clear that transgenic plants are an economic and efficient alternative to fermentation for large-scale production of vaccine antigens. The oral delivery of plant-made vaccines is particularly attractive since the expensive purification step can be avoided further reducing the cost per dose. This review covers the current status of plant-produced vaccines for the prevention of disease in animals and focuses on barriers to the development of such products and methods to overcome them.
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Affiliation(s)
- J. J. Joensuu
- Department of Applied Biology, University of Helsinki, P.O. Box 27, 00014 Helsinki, Finland
- Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON Canada N5V 4T3
| | - V. Niklander-Teeri
- Department of Applied Biology, University of Helsinki, P.O. Box 27, 00014 Helsinki, Finland
| | - J. E. Brandle
- Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON Canada N5V 4T3
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405
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Hensel G, Valkov V, Middlefell-Williams J, Kumlehn J. Efficient generation of transgenic barley: the way forward to modulate plant-microbe interactions. JOURNAL OF PLANT PHYSIOLOGY 2008; 165:71-82. [PMID: 17905476 DOI: 10.1016/j.jplph.2007.06.015] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2007] [Revised: 06/06/2007] [Accepted: 06/10/2007] [Indexed: 05/03/2023]
Abstract
Stable genetic transformation represents the gold standard approach to the detailed elucidation of plant gene functions. This is particularly relevant in barley, an important experimental model widely employed in applied molecular, genetic and cell biological research, and biotechnology. Presented are details of the establishment of a protocol for Agrobacterium-mediated gene transfer to immature embryos, which enables the highly efficient generation of transgenic barley. Advancements were achieved through comparative experiments on the influence of various explant treatments and co-cultivation conditions. The analysis of representative numbers of transgenic lines revealed that the obtained T-DNA copy numbers are typically low, the generative transmission of the recombinant DNA is in accordance with the Mendelian rules and the vast majority of the primary transgenics produce progeny that expresses the respective transgene product. Moreover, the newly established protocol turned out to be useful to transform not only the highly amenable cultivar (cv.) 'Golden Promise' but also other spring and winter barley genotypes, albeit with substantially lower efficiency. As a major result of this study, a very useful tool is now available for future functional gene analyses as well as genetic engineering approaches. With the aim to modify the expression of barley genes putatively involved in plant-fungus interactions, numerous transgenic plants have been generated using diverse expression cassettes. These plants represent an example of how transformation technology may contribute to further our understanding of important biological processes.
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Affiliation(s)
- Goetz Hensel
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Plant Reproductive Biology, Corrensstr. 3, 06466 Gatersleben, Germany.
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406
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Lemaux PG. Genetically Engineered Plants and Foods: A Scientist's Analysis of the Issues (Part I). ANNUAL REVIEW OF PLANT BIOLOGY 2008; 59:771-812. [PMID: 18284373 DOI: 10.1146/annurev.arplant.58.032806.103840] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Through the use of the new tools of genetic engineering, genes can be introduced into the same plant or animal species or into plants or animals that are not sexually compatible-the latter is a distinction with classical breeding. This technology has led to the commercial production of genetically engineered (GE) crops on approximately 250 million acres worldwide. These crops generally are herbicide and pest tolerant, but other GE crops in the pipeline focus on other traits. For some farmers and consumers, planting and eating foods from these crops are acceptable; for others they raise issues related to safety of the foods and the environment. In Part I of this review some general and food issues raised regarding GE crops and foods will be addressed. Responses to these issues, where possible, cite peer-reviewed scientific literature. In Part II to appear in 2009, issues related to environmental and socioeconomic aspects of GE crops and foods will be covered.
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Affiliation(s)
- Peggy G Lemaux
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA.
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407
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Chen L, Zhang Z, Liang H, Liu H, Du L, Xu H, Xin Z. Overexpression of TiERF1 enhances resistance to sharp eyespot in transgenic wheat. JOURNAL OF EXPERIMENTAL BOTANY 2008; 59:4195-204. [PMID: 18953072 PMCID: PMC2639029 DOI: 10.1093/jxb/ern259] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2008] [Revised: 09/25/2008] [Accepted: 09/26/2008] [Indexed: 05/19/2023]
Abstract
Wheat sharp eyespot, primarily caused by a soil-borne fungus Rhizoctonia cerealis, has become one of the most serious diseases of wheat in China. In this study, an ethylene response factor (ERF) gene from a wheat relative Thinopyrum intermedium, TiERF1, was characterized further, transgenic wheat lines expressing TiERF1 were developed, and the resistance of the transgenic wheat lines against R. cerealis was investigated. Southern blotting analysis indicated that at least two copies of the TiERF1 gene exist in the T. intermedium genome. Yeast one-hybrid assay indicated that the activation domain of TiERF1 is essential for activating the transcript of the reporter gene with the GCC-box cis-element. The TiERF1 gene was introduced into a Chinese wheat cultivar, Yangmai12, by biolistic bombardment. Results of PCR and Southern blotting analyses indicated that TiERF1 was successfully integrated into the genome of the transgenic wheat, where it can be passed down from the T0 to T4 generations. Quantitative reverse transcription-PCR analysis demonstrated that TiERF1 could be overexpressed in the stable transgenic plants, in which the expression levels of wheat pathogenesis-related (PR) genes primarily in the ethylene-dependent signal pathway, such as a chitinase gene and a beta-1,3-glucanase gene, were increased dramatically. Disease tests indicated that the overexpression of TiERF1 conferred enhanced resistance to sharp eyespot in the transgenic wheat lines compared with the wild-type and silenced TiERF1 plants. These results suggested that the overexpression of TiERF1 enhances resistance to sharp eyespot in transgenic wheat lines by activating PR genes primarily in the ethylene-dependent pathway.
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408
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Lloyd AH, Milligan AS, Langridge P, Able JA. TaMSH7: a cereal mismatch repair gene that affects fertility in transgenic barley (Hordeum vulgare L.). BMC PLANT BIOLOGY 2007; 7:67. [PMID: 18096080 PMCID: PMC2234410 DOI: 10.1186/1471-2229-7-67] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2007] [Accepted: 12/20/2007] [Indexed: 05/18/2023]
Abstract
BACKGROUND Chromosome pairing, recombination and DNA repair are essential processes during meiosis in sexually reproducing organisms. Investigating the bread wheat (Triticum aestivum L.) Ph2 (Pairing homoeologous) locus has identified numerous candidate genes that may have a role in controlling such processes, including TaMSH7, a plant specific member of the DNA mismatch repair family. RESULTS Sequencing of the three MSH7 genes, located on the short arms of wheat chromosomes 3A, 3B and 3D, has revealed no significant sequence divergence at the amino acid level suggesting conservation of function across the homoeogroups. Functional analysis of MSH7 through the use of RNAi loss-of-function transgenics was undertaken in diploid barley (Hordeum vulgare L.). Quantitative real-time PCR revealed several T0 lines with reduced MSH7 expression. Positive segregants from two T1 lines studied in detail showed reduced MSH7 expression when compared to transformed controls and null segregants. Expression of MSH6, another member of the mismatch repair family which is most closely related to the MSH7 gene, was not significantly reduced in these lines. In both T1 lines, reduced seed set in positive segregants was observed. CONCLUSION Results presented here indicate, for the first time, a distinct functional role for MSH7 in vivo and show that expression of this gene is necessary for wild-type levels of fertility. These observations suggest that MSH7 has an important function during meiosis and as such remains a candidate for Ph2.
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Affiliation(s)
- Andrew H Lloyd
- School of Agriculture, Food & Wine, The University of Adelaide, Waite Campus, PMB1, Glen Osmond, South Australia, 5064, Australia
- School of Molecular & Biomedical Science, The University of Adelaide, South Australia, 5005, Australia
| | - Andrew S Milligan
- Australian Centre for Plant Functional Genomics, School of Agriculture, Food & Wine, The University of Adelaide, Waite Campus, PMB1, Glen Osmond, South Australia, 5064, Australia
| | - Peter Langridge
- Australian Centre for Plant Functional Genomics, School of Agriculture, Food & Wine, The University of Adelaide, Waite Campus, PMB1, Glen Osmond, South Australia, 5064, Australia
| | - Jason A Able
- School of Agriculture, Food & Wine, The University of Adelaide, Waite Campus, PMB1, Glen Osmond, South Australia, 5064, Australia
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409
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Genetic transformation of barley microspores using anther bombardment. Biotechnol Lett 2007; 30:945-9. [DOI: 10.1007/s10529-007-9618-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Accepted: 11/15/2007] [Indexed: 11/26/2022]
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410
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Chernobrovkina MA, Sidorov EA, Baranov IA, Kharchenko PN, Dolgov SV. The effect of the parameters of biolistic transformation of spring barley (Hordeum vulgare L.) on the level of transient expression of GFP reporter gene. BIOL BULL+ 2007. [DOI: 10.1134/s1062359007060040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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411
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Chen YP, Xing LP, Wu GJ, Wang HZ, Wang XE, Cao AZ, Chen PD. Plastidial glutathione reductase from Haynaldia villosa is an enhancer of powdery mildew resistance in wheat (Triticum aestivum). PLANT & CELL PHYSIOLOGY 2007; 48:1702-12. [PMID: 17947258 DOI: 10.1093/pcp/pcm142] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
A full-length cDNA (Hv-GR) whose transcript accumulation increased in response to infection by Blumeria graminis DC.f.sp. tritici (Bgt) was isolated from Haynaldia villosa. Southern analysis revealed a single copy of Hv-GR present in H. villosa. This gene encodes a glutathione reductase (GR) with high similarity to chloroplastic GRs from other plant species. Chloroplastic localization of Hv-GR was confirmed by targeting of the green fluorescent protein (GFP)-Hv-GR fusion protein to chloroplasts of epidermal guard cells. Following inoculation with Bgt, transcript accumulation of Hv-GR increased in a resistant line of wheat, but no significant change was observed in a susceptible line. In vivo function of Hv-GR in converting oxidized glutathione (GSSG) to the reduced form (GSH) was verified through heterologous expression of Hv-GR in a yeast GR-deficient mutant. As expected, overexpression of this gene resulted in increased resistance of the mutant to H(2)O(2), indicating a critical role for Hv-GR in protecting cells against oxidative stress. Moreover, overexpression of Hv-GR in a susceptible wheat variety, Triticum aestivum cv. Yangmai 158, enhanced resistance to powdery mildew and induced transcript accumulation of other pathogenesis-related genes, PR-1a and PR-5, through increasing the foliar GSH/GSSG ratio. Therefore, we concluded that a high ratio of GSH to GSSG is required for wheat defense against Bgt, and that chloroplastic GR enzymes might serve as a redox mediator for NPR1 activation.
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Affiliation(s)
- Ya-Ping Chen
- The National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, PR China
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412
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Vickers CE, Schenk PM, Li D, Mullineaux PM, Gresshoff PM. pGFPGUSPlus, a new binary vector for gene expression studies and optimising transformation systems in plants. Biotechnol Lett 2007; 29:1793-6. [PMID: 17687623 DOI: 10.1007/s10529-007-9467-6] [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: 06/06/2007] [Accepted: 06/25/2007] [Indexed: 10/23/2022]
Abstract
A binary vector containing two reporter gene cassettes has been developed. This vector is ideal for optimising new plant transformation systems. Following optimisation, one of the reporter genes can be replaced with a gene of interest; the second can be used as a marker to confirm transgenic lines, and to estimate locus number and determine zygosity. This allows simple, efficient and economical screening for homozygous single-insert lines and azygous controls.
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Affiliation(s)
- Claudia E Vickers
- Department of Biological Sciences, The University of Essex, Wivenhoe Park, Colchester, C04 3SQ, England
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413
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Shepherd DN, Mangwende T, Martin DP, Bezuidenhout M, Kloppers FJ, Carolissen CH, Monjane AL, Rybicki EP, Thomson JA. Maize streak virus-resistant transgenic maize: a first for Africa. PLANT BIOTECHNOLOGY JOURNAL 2007; 5:759-67. [PMID: 17924935 DOI: 10.1111/j.1467-7652.2007.00279.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In this article, we report transgene-derived resistance in maize to the severe pathogen maize streak virus (MSV). The mutated MSV replication-associated protein gene that was used to transform maize showed stable expression to the fourth generation. Transgenic T2 and T3 plants displayed a significant delay in symptom development, a decrease in symptom severity and higher survival rates than non-transgenic plants after MSV challenge, as did a transgenic hybrid made by crossing T2 Hi-II with the widely grown, commercial, highly MSV-susceptible, white maize genotype WM3. To the best of our knowledge, this is the first maize to be developed with transgenic MSV resistance and the first all-African-produced genetically modified crop plant.
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Affiliation(s)
- Dionne N Shepherd
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch 7701, South Africa.
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414
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Agharkar M, Lomba P, Altpeter F, Zhang H, Kenworthy K, Lange T. Stable expression of AtGA2ox1 in a low-input turfgrass (Paspalum notatum Flugge) reduces bioactive gibberellin levels and improves turf quality under field conditions. PLANT BIOTECHNOLOGY JOURNAL 2007; 5:791-801. [PMID: 17764521 DOI: 10.1111/j.1467-7652.2007.00284.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Bahiagrass (Paspalum notatum Flugge) is a prime candidate for molecular improvement of turf quality. Its persistence and low input characteristics made it the dominant utility turfgrass along highways in the south-eastern USA. However, the comparatively poor turf quality due to reduced turf density and prolific production of unsightly inflorescences currently limits the widespread use of bahiagrass as residential turf. Alteration of endogenous gibberellin (GA) levels by application of growth regulators or transgenic strategies has modified plant architecture in several crops. GA catabolizing AtGA2ox1 was subcloned under the control of the constitutive maize ubiquitin promoter and Nos 3'UTR. A minimal AtGA2ox1 expression cassette lacking vector backbone sequences was stably introduced into apomictic bahiagrass by biolistic gene transfer as confirmed by Southern blot analysis. Expression of AtGA2ox1 in bahiagrass as indicated by reverse transcription-polymerase chain reaction and Northern blot analysis resulted in a significant reduction of endogenous bioactive GA(1) levels compared to wild type. Interestingly, transgenic plants displayed an increased number of vegetative tillers which correlated with the level of AtGA2ox1 expression and enhanced turf density under field conditions. This indicates that GAs contribute to signalling the outgrowth of axillary buds in this perennial grass. Transgenic plants also showed decreased stem length and delayed flowering under controlled environment and field conditions. Consequently, turf quality following weekly mowing was improved in transgenic bahiagrass. Transgene expression and phenotype were transmitted to seed progeny. Argentine bahiagrass produces seeds asexually by apomixis, which reduces the risk of unintended transgene dispersal by pollen and results in uniform progeny.
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Affiliation(s)
- Mrinalini Agharkar
- Agronomy Department, Plant Molecular Biology Program, Genetics Institute, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, USA
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415
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Prakash NS, Prasad V, Chidambram TP, Cherian S, Jayaprakash TL, Dasgupta S, Wang Q, Mann MT, Spencer TM, Boddupalli RS. Effect of promoter driving selectable marker on corn transformation. Transgenic Res 2007; 17:695-704. [PMID: 17952623 DOI: 10.1007/s11248-007-9149-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2007] [Accepted: 10/04/2007] [Indexed: 11/25/2022]
Abstract
Identification of an appropriate selection agent and its corresponding selectable marker gene is one of the first steps in establishing a transformation protocol for a given plant species. As the promoter controls expression level of the genes, the promoter driving the selectable marker gene can affect transformation. However, investigations into the direct effect of promoters driving selectable marker on transformation are lacking in the literature though many reports of relative strengths of promoters driving reporter genes like GUS or CAT or GFP are available. In the present study, we have compared rice Actin1 and CaMV.35S (commonly used promoters in monocotyledonous plant transformation) promoters driving nptII for their effectiveness in paromomycin selection of transgenic corn events. To enable statistically meaningful analysis of the results, a large sample size of nearly 5,000 immature embryos (explants) was employed producing approximately 1,250 independent events from each of the two constructs in four independent experiments. The rate of appearance of resistant calli and percentage of resistant calli recovered was higher with P-Os.Actin1/nptII/nos3' as compared to P-CaMV.35S/nptII/nos3' in all four experiments. There was no appreciable difference either in the frequency of plant regeneration or in the morphological characteristics of plants recovered from the two constructs. Although the escape rate trended lower with P-Os.Actin1 as compared to P-CaMV.35S, the recovery of low copy events was significantly higher with P-CaMV.35S. The higher transformation frequency with P-Os.Actin1 could be related to the strength of this promoter as compared to P-CaMV.35S in the explants and/or calli. Based on these results, we infer that the promoter driving the selectable marker is an important factor to be considered while establishing a high throughput transformation protocol as it could not only influence the transformation frequency but also the copy number of the transgene in the recovered transgenics.
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Affiliation(s)
- N Shiva Prakash
- Monsanto Research Centre, #44/2A, Vasanths' Business Park, Bellary Road, NH:7, Hebbal, Bangalore, India
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416
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Chen R, Xue G, Chen P, Yao B, Yang W, Ma Q, Fan Y, Zhao Z, Tarczynski MC, Shi J. Transgenic maize plants expressing a fungal phytase gene. Transgenic Res 2007; 17:633-43. [PMID: 17932782 DOI: 10.1007/s11248-007-9138-3] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Accepted: 08/24/2007] [Indexed: 11/26/2022]
Abstract
Maize seeds are the major ingredient of commercial pig and poultry feed. Phosphorus in maize seeds exists predominantly in the form of phytate. Phytate phosphorus is not available to monogastric animals and phosphate supplementation is required for optimal animal growth. Undigested phytate in animal manure is considered a major source of phosphorus pollution to the environment from agricultural production. Microbial phytase produced by fermentation as a feed additive is widely used to manage the nutritional and environmental problems caused by phytate, but the approach is associated with production costs for the enzyme and requirement of special cares in feed processing and diet formulation. An alternative approach would be to produce plant seeds that contain high phytase activities. We have over-expressed Aspergillus niger phyA2 gene in maize seeds using a construct driven by the maize embryo-specific globulin-1 promoter. Low-copy-number transgenic lines with simple integration patterns were identified. Western-blot analysis showed that the maize-expressed phytase protein was smaller than that expressed in yeast, apparently due to different glycosylation. Phytase activity in transgenic maize seeds reached approximately 2,200 units per kg seed, about a 50-fold increase compared to non-transgenic maize seeds. The phytase expression was stable across four generations. The transgenic seeds germinated normally. Our results show that the phytase expression lines can be used for development of new maize hybrids to improve phosphorus availability and reduce the impact of animal production on the environment.
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Affiliation(s)
- Rumei Chen
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, P.R. China
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417
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Wilhelmson A, Kallio PT, Oksman-Caldentey KM, Nuutila AM. Heterologous expression of Vitreoscilla haemoglobin in barley (Hordeum vulgare). PLANT CELL REPORTS 2007; 26:1773-83. [PMID: 17569049 DOI: 10.1007/s00299-007-0393-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Revised: 05/04/2007] [Accepted: 05/18/2007] [Indexed: 05/15/2023]
Abstract
The vhb gene encoding Vitreoscilla haemoglobin (VHb) was transferred to barley with the aim of studying the role of oxygen availability in germination and growth. Previous findings indicate that VHb expression improves the efficiency of energy generation during oxygen-limited growth, and germination is known to be an energy demanding growth stage during which the embryos also suffer from oxygen deficiency. When subjected to oxygen deficiency, the roots of vhb-expressing barley plants showed a smaller increase in alcohol dehydrogenase (ADH) activity than those of the control plants. This indicates that VHb plants experienced less severe oxygen deficiency than the control plants, possibly due to the ability of VHb to substitute ADH for recycling NADH and maintaining glycolysis. In contrast to previous findings, we found that constitutive vhb expression did not improve the germination rate of barley kernels in any of the conditions studied. In some cases, vhb expression even slowed down germination slightly. VHb production also appeared to restrict root formation in young seedlings. The adverse effects of VHb on germination and root growth may be related to its ability to scavenge nitric oxide (NO), an important signal molecule in both seed germination and root formation. Because NO has both cytotoxic and stimulating properties, the effect of vhb expression in plants may depend on the level and role of endogenous NO in the conditions studied. VHb production also affected the levels of endogenous barley haemoglobin, which may explain the relatively moderate effects of VHb in this study.
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Affiliation(s)
- Annika Wilhelmson
- VTT Technical Research Centre of Finland, P.O. Box 1000, 02044 VTT, Espoo, Finland.
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418
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Cloutier S, McCallum BD, Loutre C, Banks TW, Wicker T, Feuillet C, Keller B, Jordan MC. Leaf rust resistance gene Lr1, isolated from bread wheat (Triticum aestivum L.) is a member of the large psr567 gene family. PLANT MOLECULAR BIOLOGY 2007; 65:93-106. [PMID: 17611798 DOI: 10.1007/s11103-007-9201-8] [Citation(s) in RCA: 158] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2007] [Accepted: 06/08/2007] [Indexed: 05/16/2023]
Abstract
In hexaploid wheat, leaf rust resistance gene Lr1 is located at the distal end of the long arm of chromosome 5D. To clone this gene, an F(1)-derived doubled haploid population and a recombinant inbred line population from a cross between the susceptible cultivar AC Karma and the resistant line 87E03-S2B1 were phenotyped for resistance to Puccinia triticina race 1-1 BBB that carries the avirulence gene Avr1. A high-resolution genetic map of the Lr1 locus was constructed using microsatellite, resistance gene analog (RGA), BAC end (BE), and low pass (LP) markers. A physical map of the locus was constructed by screening a hexaploid wheat BAC library from cultivar Glenlea that is known to have Lr1. The locus comprised three RGAs from a gene family related to RFLP marker Xpsr567. Markers specific to each paralog were developed. Lr1 segregated with RGA567-5 while recombinants were observed for the other two RGAs. Transformation of the susceptible cultivar Fielder with RGA567-5 demonstrated that it corresponds to the Lr1 resistance gene. In addition, the candidate gene was also confirmed by virus-induced gene silencing. Twenty T (1) lines from resistant transgenic line T (0)-938 segregated for resistance, partial resistance and susceptibility to Avr1 corresponding to a 1:2:1 ratio for a single hemizygous insertion. Transgene presence and expression correlated with the phenotype. The resistance phenotype expressed by Lr1 seemed therefore to be dependant on the zygosity status. T (3)-938 sister lines with and without the transgene were further tested with 16 virulent and avirulent rust isolates. Rust reactions were all as expected for Lr1 thereby providing additional evidence toward the Lr1 identity of RGA567-5. Sequence analysis of Lr1 indicated that it is not related to the previously isolated Lr10 and Lr21 genes and unlike these genes, it is part of a large gene family.
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Affiliation(s)
- Sylvie Cloutier
- Cereal Research Centre, Agriculture and Agri-Food Canada, R3T 2M9, Winnipeg, MB, Canada.
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419
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Chiera JM, Bouchard RA, Dorsey SL, Park E, Buenrostro-Nava MT, Ling PP, Finer JJ. Isolation of two highly active soybean (Glycine max (L.) Merr.) promoters and their characterization using a new automated image collection and analysis system. PLANT CELL REPORTS 2007; 26:1501-9. [PMID: 17503049 DOI: 10.1007/s00299-007-0359-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Accepted: 03/31/2007] [Indexed: 05/15/2023]
Abstract
A novel automated image collection and analysis system was used to compare two new soybean (Glycine max (L.) Merr.) promoters with the cauliflower mosaic virus 35S (CaMV35S) promoter, which was used as an expression standard. For expression comparisons, various permutations of a soybean polyubiquitin (Gmubi) promoter, a soybean heat shock protein 90-like (GmHSP90L) promoter and the CaMV35S promoter were placed upstream of a green fluorescent protein (gfp) gene. DNA constructs were introduced via particle bombardment into excised cotyledons of germinating lima bean (Phaseolus lunatus L.) seeds, which were arranged in Petri dishes for automated image capture and image analysis. The automated system allowed monitoring and quantification of gfp gene expression in the same piece of tissue over time. The Gmubi promoter, with its intronic region intact, showed the highest expression that was over five times stronger than the CaMV35S promoter. When an intronic region was removed from the Gmubi promoter, GFP expression was reduced, but was still over two times greater than with the CaMV35S promoter. The full-length soybean GmHSP90L promoter was four times stronger than the CaMV35S promoter. Truncation of the GmHSP90L promoter resulted in stepwise decreases in promoter strength, which appear to correspond to removal of regulatory elements. Automated image capture and analysis allowed the rapid and efficient evaluation of these new promoters.
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Affiliation(s)
- Joseph M Chiera
- Department of Horticulture and Crop Science, OARDC/The Ohio State University, 1680 Madison Ave., Wooster, OH 44691, USA
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420
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Pastori GM, Huttly A, West J, Sparks C, Pieters A, Luna CM, Jones HD, Foyer CH. The maize Activator/Dissociation system is functional in hexaploid wheat through successive generations. FUNCTIONAL PLANT BIOLOGY : FPB 2007; 34:835-843. [PMID: 32689411 DOI: 10.1071/fp07112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2007] [Accepted: 07/03/2007] [Indexed: 06/11/2023]
Abstract
The aim of the present study was to provide useful background information and evidence of the functionality of the maize Activator/Dissociation (Ac/Ds) system in hexaploid wheat. Two transgenic parental wheat lines, one harbouring the immobilised Ac element (iAc) and the other the Ds element (pUbi[Ds-uidA]bar), were crossed. Transient GUS assays confirmed that the iAc transposase is active in hexaploid wheat. Selected F1 and F2 lines were analysed by PCR using primers specific to Ac, uidA and bar genes. The primer pair Ubi/bar-tag was used to detect excision of the Ds-uidA sequence, which occurred at a frequency of 39% in the F1 generation. Lines free of Ac and showing evidence of Ds excision were subject to Southern analysis, which indicated that at least one transposition event might have occurred in these lines. Although more evidence is required to unequivocally support the reintegration of the Ds element in the wheat genome, the evidence presented here nevertheless demonstrates the effectiveness and potential value of using this system to tag genes in wheat.
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Affiliation(s)
- Gabriela M Pastori
- Crop Performance and Improvement Division, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - Alison Huttly
- Crop Performance and Improvement Division, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - Jevon West
- Crop Performance and Improvement Division, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - Caroline Sparks
- Crop Performance and Improvement Division, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - Alejandro Pieters
- IVI, Centro de Ecología, Altos de Pipe, Carretera Panamericana Km 11, Apartado 21827, Caracas 1020-A, Venezuela
| | - Celina M Luna
- Instituto de Fitopatología y FisiologíaVegetal (IFFIVE)-INTA, Camino 60 cuadras Km 5, 5009 Cordoba, Argentina
| | - Huw D Jones
- Crop Performance and Improvement Division, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - Christine H Foyer
- School of Agriculture, Food and Rural Development, Agriculture Building, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
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421
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Oh SJ, Kwon CW, Choi DW, Song SI, Kim JK. Expression of barley HvCBF4 enhances tolerance to abiotic stress in transgenic rice. PLANT BIOTECHNOLOGY JOURNAL 2007; 5:646-56. [PMID: 17614953 DOI: 10.1111/j.1467-7652.2007.00272.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
C-repeat/dehydration-responsive element binding factors (CBF/DREBs) are a family of transcription factors that regulate freezing tolerance in Arabidopsis. As a step towards understanding the stress response of monocotyledonous plants, we isolated a barley gene HvCBF4 whose expression is induced by low-temperature stress. Transgenic over-expression of HvCBF4 in rice resulted in an increase in tolerance to drought, high-salinity and low-temperature stresses without stunting growth. Interestingly, under low-temperature conditions, the maximum photochemical efficiency of photosystem II in the dark-adapted state (F(v)/F(m), where F(v) is the variable fluorescence and F(m) is the maximum fluorescence) in HvCBF4 plants was higher by 20% and 10% than that in non-transgenic and CBF3/DREB1A plants, respectively. Using the 60K Rice Whole Genome microarray, 15 rice genes were identified that were activated by HvCBF4. When compared with 12 target rice genes of CBF3/DREB1A, five genes were common to both HvCBF4 and CBF3/DREB1A, and 10 and seven genes were specific to HvCBF4 and CBF3/DREB1A, respectively. Interestingly, HvCBF4 did not activate Dip1 and Lip5, two important target genes of CBF3/DREB1A, in transgenic rice under normal growth conditions, but their expression was enhanced by HvCBF4 under low-temperature conditions. Our results suggest that CBF/DREBs of barley act differently from those of Arabidopsis in transgenic rice.
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Affiliation(s)
- Se-Jun Oh
- School of Biotechnology and Environmental Engineering, Myongji University, Yongin 449-728, South Korea
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422
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Primavesi LF, Wu H, Mudd EA, Day A, Jones HD. Visualisation of plastids in endosperm, pollen and roots of transgenic wheat expressing modified GFP fused to transit peptides from wheat SSU RubisCO, rice FtsZ and maize ferredoxin III proteins. Transgenic Res 2007; 17:529-43. [PMID: 17710559 DOI: 10.1007/s11248-007-9126-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2007] [Accepted: 07/31/2007] [Indexed: 10/22/2022]
Abstract
The ability to target marker proteins to specific subcellular compartments is a powerful research tool to study the structure and development of organelles. Here transit sequences from nuclear-encoded, plastid proteins, namely rice FtsZ, maize non-photosynthetic ferredoxin III (FdIII) and the small subunit of RubisCO were used to target a modified synthetic GFP (S65G, S72A) to plastids. The localisations of the fusion proteins expressed in transgenic wheat plants and under the control of the rice actin promoter were compared to an untargeted GFP control. GFP fluorescence was localised to non-green plastids in pollen, roots and seed endosperm and detected in isolated leaf chloroplasts using a GFP-specific antibody. Transit peptides appeared to influence the relative fluorescence intensities of plastids in different tissues. This is consistent with differential targeting and/or turnover of GFP fusion proteins in different plastid types. Replacement of GFP sequences with alternative coding regions enables immediate applications of our vectors for academic research and commercial applications.
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423
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Zhang S, Dong JG, Wang T, Guo S, Glassman K, Ranch J, Nichols SE. High level accumulation of alpha-glucan in maize kernels by expressing the gtfD gene from Streptococcus mutans. Transgenic Res 2007; 16:467-78. [PMID: 17624807 DOI: 10.1007/s11248-006-9049-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2006] [Accepted: 10/10/2006] [Indexed: 10/23/2022]
Abstract
Glucosyltransferases (GTFs, EC.2.4.1.5) are bacterial enzymes that catalyze the polymerization of glucose residues from sucrose, leading to the production of high molecular weight glucan with alpha-1,3 /alpha-1,6 linkages. Such glucans, with many potential food and industrial applications, do not normally exist in higher plants. We fused a mutant form of the gtfD gene from Sreptococcus mutans with the maize (Zea mays L.) chloroplastic Brittle 1 transit peptide for amyloplast targeting. This construct, driven by the ubiquitin promoter, was introduced into maize by Agrobacterium-mediated transformation. We developed a novel HPLC-based method that enabled us differentially to distinguish transgene glucan from other endogenous polysaccharides in maize kernels. Using this method, we screened over 100 transgenic plants for the presence of GTF-produced glucan whose content varied between 0.8 and 14% of dry weight in the mature transgenic seeds. The mature transgenic plants were indistinguishable from wildtype plants in growth rate and morphology. Furthermore, starch granule size in the transgenic maize kernel was unaffected by the accumulation of the foreign polysaccharide. Mutation in Sh2, which encodes a subunit of ADP-glucose pyrophosphorylase, had no effect on glucan accumulation caused by gtfD expression. Our results indicated that high levels of novel carbohydrate polymer can be accumulated in crop plants through transgene technology.
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Affiliation(s)
- Shirong Zhang
- Pioneer Hi-Bred International, Inc., a DuPont company, Johnston, IA 50131, USA.
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424
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Wadenbäck J, von Arnold S, Egertsdotter U, Walter MH, Grima-Pettenati J, Goffner D, Gellerstedt G, Gullion T, Clapham D. Lignin biosynthesis in transgenic Norway spruce plants harboring an antisense construct for cinnamoyl CoA reductase (CCR). Transgenic Res 2007; 17:379-92. [PMID: 17610137 DOI: 10.1007/s11248-007-9113-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Accepted: 06/01/2007] [Indexed: 10/23/2022]
Abstract
An attractive objective in tree breeding is to reduce the content of lignin or alter its composition, in order to facilitate delignification in pulping. This has been achieved in transgenic angiosperm tree species. In this study we show for the first time that changes in lignin content and composition can be achieved in a conifer by taking a transgenic approach. Lignin content and composition have been altered in five-year-old transgenic plants of Norway spruce (Picea abies [L.] Karst) expressing the Norway spruce gene encoding cinnamoyl CoA reductase (CCR) in antisense orientation. The asCCR plants had a normal phenotype but smaller stem widths compared to the transformed control plants. The transcript abundance of the sense CCR gene was reduced up to 35% relative to the transformed control. The corresponding reduction in lignin content was up to 8%, which is at the lower limit of the 90-99% confidence intervals reported for natural variation. The contribution of H-lignin to the non-condensed fraction of lignin, as judged by thioacidolysis, was reduced up to 34%. The H-lignin content was strongly correlated with the total lignin content. Furthermore, the kappa number of small-scale Kraft pulps from one of the most down-regulated lines was reduced 3.5%. The transcript abundances of the various lignin biosynthetic genes were down-regulated indicating co-regulation of the biosynthetic pathway.
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Affiliation(s)
- Johan Wadenbäck
- Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences (SLU), P.O. Box 7080, 750 07 Uppsala, Sweden.
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425
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Quilis J, Meynard D, Vila L, Avilés FX, Guiderdoni E, San Segundo B. A potato carboxypeptidase inhibitor gene provides pathogen resistance in transgenic rice. PLANT BIOTECHNOLOGY JOURNAL 2007; 5:537-53. [PMID: 17547659 DOI: 10.1111/j.1467-7652.2007.00264.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
A defensive role against insect attack has been traditionally attributed to plant protease inhibitors. Here, evidence is described of the potential of a plant protease inhibitor, the potato carboxypeptidase inhibitor (PCI), to provide resistance to fungal pathogens when expressed in rice as a heterologous protein. It is shown that rice plants constitutively expressing the pci gene exhibit resistance against the economically important pathogens Magnaporthe oryzae and Fusarium verticillioides. A M. oryzae carboxypeptidase was purified by affinity chromatography and further characterized by mass spectrometry. This fungal carboxypeptidase was found to be a novel carboxypeptidase B which was fully inhibited by PCI. Overall, the results indicate that PCI exerts its antifungal activity through the inhibition of this particular fungal carboxypeptidase B. Although pci confers protection against fungal pathogens in transgenic rice, a significant cost in insect resistance is observed. Thus, the weight gain of larvae of the specialist insect Chilo suppressalis (striped stem borer) and the polyphagous insect Spodoptera littoralis (Egyptian cotton worm) fed on pci rice is significantly larger than that of insects fed on wild-type plants. Homology-based modelling revealed structural similarities between the predicted structure of the M. oryzae carboxypeptidase B and the crystal structure of insect carboxypeptidases, indicating that PCI may function not only as an inhibitor of fungal carboxypeptidases, but also as an inhibitor of insect carboxypeptidases. The potential impact of the pci gene in terms of protection against fungal and insect diseases is discussed.
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Affiliation(s)
- Jordi Quilis
- Consorcio CSIC-IRTA Laboratorio de Genética Molecular Vegetal, Departamento de Genética Molecular, Instituto de Biología Molecular de Barcelona, CSIC, Jordi Girona 18, Barcelona, Spain
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426
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Sugio A, Yang B, Zhu T, White FF. Two type III effector genes of Xanthomonas oryzae pv. oryzae control the induction of the host genes OsTFIIAgamma1 and OsTFX1 during bacterial blight of rice. Proc Natl Acad Sci U S A 2007; 104:10720-5. [PMID: 17563377 PMCID: PMC1965579 DOI: 10.1073/pnas.0701742104] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Xanthomonas oryzae pv. oryzae strain PXO99(A) induces the expression of the host gene Os8N3, which results in increased host susceptibility to bacterial blight of rice. Here, we show that PXO99(A) affects the expression of two additional genes in a type III secretion system-dependent manner, one encoding a bZIP transcription factor (OsTFX1) and the other the small subunit of the transcription factor IIA located on chromosome 1 (OsTFIIAgamma1). Induction of OsTFX1 and OsTFIIAgamma1 depended on the type III effector genes pthXo6 and pthXo7, respectively, both encoding two previously undescribed members of the transcription activator-like (TAL) effector family. pthXo7 is strain-specific and may reflect adaptation to the resistance mediated by xa5, an allele of OsTFIIAgamma5 encoding a second form of the TFIIA small subunit on chromosome 5 of rice. The loss of pthXo6 resulted in reduced pathogen virulence, and ectopic expression of OsTFX1 abrogated the requirement for pthXo6 for full virulence. X. oryzae pv. oryzae therefore modulates the expression of multiple host genes using multiple TAL effectors from a single strain, and evidence supports the hypothesis that expression of the associated host genes contributes to host susceptibility to disease.
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Affiliation(s)
- Akiko Sugio
- *Department of Plant Pathology, Kansas State University, Manhattan, KS 66506
- Department of Disease and Stress Biology, John Innes Centre, Norwich Research Park, Colney Lane, Norwich NR4 7UH, United Kingdom; and
| | - Bing Yang
- *Department of Plant Pathology, Kansas State University, Manhattan, KS 66506
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011
| | - Tong Zhu
- Syngenta Biotechnology, Inc., 3054 Cornwallis Road, Research Triangle Park, NC 27709
| | - Frank F. White
- *Department of Plant Pathology, Kansas State University, Manhattan, KS 66506
- To whom correspondence should be addressed. E-mail:
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427
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Shimono M, Sugano S, Nakayama A, Jiang CJ, Ono K, Toki S, Takatsuji H. Rice WRKY45 plays a crucial role in benzothiadiazole-inducible blast resistance. THE PLANT CELL 2007; 19:2064-76. [PMID: 17601827 PMCID: PMC1955718 DOI: 10.1105/tpc.106.046250] [Citation(s) in RCA: 394] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Benzothiadiazole (BTH) is a so-called plant activator and protects plants from diseases by activating the salicylic acid (SA) signaling pathway. By microarray screening, we identified BTH- and SA-inducible WRKY transcription factor (TF) genes that were upregulated within 3 h after BTH treatment. Overexpression of one of them, WRKY45, in rice (Oryza sativa) markedly enhanced resistance to rice blast fungus. RNA interference-mediated knockdown of WRKY45 compromised BTH-inducible resistance to blast disease, indicating that it is essential for BTH-induced defense responses. In a transient expression system, WRKY45 activated reporter gene transcription through W-boxes. Epistasis analysis suggested that WRKY45 acts in the SA signaling pathway independently of NH1, a rice ortholog of Arabidopsis thaliana NPR1, which distinguishes WRKY45 from known Arabidopsis WRKY TFs. Two defense-related genes, encoding a glutathione S-transferase and a cytochrome P450, were found to be regulated downstream of WRKY45 but were not regulated by NH1, consistent with the apparent independence of the WRKY45- and NH1-dependent pathways. Defense gene expression in WRKY45-overexpressed rice plants varied with growth conditions, suggesting that some environmental factor(s) acts downstream of WRKY45 transcription. We propose a role for WRKY45 in BTH-induced and SA-mediated defense signaling in rice and its potential utility in improving disease resistance of rice, an importance food resource worldwide.
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Affiliation(s)
- Masaki Shimono
- Plant Disease Resistance Research Unit, National Institute of Agrobiological Sciences, Ibaraki, Japan
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428
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Yu W, Han F, Gao Z, Vega JM, Birchler JA. Construction and behavior of engineered minichromosomes in maize. Proc Natl Acad Sci U S A 2007; 104:8924-9. [PMID: 17502617 PMCID: PMC1885604 DOI: 10.1073/pnas.0700932104] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Engineered minichromosomes were constructed in maize by modifying natural A and supernumerary B chromosomes. By using telomere-mediated chromosomal truncation, it was demonstrated that such an approach is feasible for the generation of minichromosomes of normal A chromosomes by selection of spontaneous polyploid events that compensate for the deficiencies produced. B chromosomes are readily fractionated by biolistic transformation of truncating plasmids. Foreign genes were faithfully expressed from integrations into normal B chromosomes and from truncated miniB chromosomes. Site-specific recombination between the terminal transgene on a miniA chromosome and a terminal site on a normal chromosome was demonstrated. It was also found that the miniA chromosome did not pair with its progenitor chromosomes during meiosis, indicating a useful property for such constructs. The miniB chromosomes are faithfully transmitted from one generation to the next but can be changed in dosage in the presence of normal B chromosomes. This approach for construction of engineered chromosomes can be easily extended to other plant species because it does not rely on cloned centromere sequences, which are species-specific. These platforms will provide avenues for studies on plant chromosome structure and function and for future developments in biotechnology and agriculture.
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Affiliation(s)
- Weichang Yu
- Division of Biological Sciences, 117 Tucker Hall, University of Missouri, Columbia, MO 65211
| | - Fangpu Han
- Division of Biological Sciences, 117 Tucker Hall, University of Missouri, Columbia, MO 65211
| | - Zhi Gao
- Division of Biological Sciences, 117 Tucker Hall, University of Missouri, Columbia, MO 65211
| | - Juan M. Vega
- Division of Biological Sciences, 117 Tucker Hall, University of Missouri, Columbia, MO 65211
| | - James A. Birchler
- Division of Biological Sciences, 117 Tucker Hall, University of Missouri, Columbia, MO 65211
- To whom correspondence should be addressed. E-mail:
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429
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Xu X, Jin F, Yu X, Ren S, Hu J, Zhang W. High-level expression of the recombinant hybrid peptide cecropinA(1-8)-magainin2(1-12) with an ubiquitin fusion partner in Escherichia coli. Protein Expr Purif 2007; 55:175-82. [PMID: 17572103 DOI: 10.1016/j.pep.2007.04.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Revised: 04/10/2007] [Accepted: 04/21/2007] [Indexed: 11/21/2022]
Abstract
The hybrid antibacterial peptide CA-MA [cecropinA(1-8)-magainin2(1-12)] with potent antimicrobial properties but no hemolytic activity is a potential alternative antibiotic. To explore a new approach for high-level expression of the hybrid peptide CA-MA in Escherichia coli, the sequence of ubiquitin (UBI) from housefly was inserted into the plasmid pQE30 to construct the vector pQEUBI. The cDNA fragment encoding CA-MA with preferred codons of E. coli was obtained by recursive PCR (rPCR) and cloned into the vector pQEUBI to express the fusion protein (His)(6)-UBI-CA-MA. The fusion protein was expressed in soluble form under the optimized conditions at high level (more than 36% of the total proteins). With (His)(6)-tag, the fusion protein was easily purified by Ni-NTA chromatography and 36 mg of fusion protein was purified from 1L of culture medium. The fusion protein was efficiently cleaved by ubiquitin C-terminal hydrolase (UCH), yielding recombinant CA-MA with high antimicrobial activity. After removing the contaminants by Ni-NTA chromatography, recombinant CA-MA was purified to homogeneity by reversed-phase HPLC and 6.8mg of pure active CA-MA was obtained from 1L culture medium. Analysis of recombinant CA-MA by MALDI-TOF-MS showed that the molecular weight of the purified recombinant CA-MA was 2559Da, which perfectly matches the mass (2559Da) calculated from the amino acid sequence. Analysis of CA-MA by circular dichroism (CD) revealed that the secondary structures of CA-MA in water solution were 17.4% alpha-helix and 82.6% random coil but no beta-sheet. Our results demonstrated that functional CA-MA can be produced in sufficient quantities using the ubiquitin fusion technique. This is the first report on the heterologous expression of a hybrid antibacterial peptide fused to ubiquitin in E. coli.
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Affiliation(s)
- Xiaoxia Xu
- State Key Laboratory of Biocontrol, College of Life Sciences, Sun Yat-sen (Zhongshan) University, Guangzhou 510275, PR China
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430
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Weise A, Altmann F, Rodriguez-Franco M, Sjoberg ER, Bäumer W, Launhardt H, Kietzmann M, Gorr G. High-level expression of secreted complex glycosylated recombinant human erythropoietin in the Physcomitrella Delta-fuc-t Delta-xyl-t mutant. PLANT BIOTECHNOLOGY JOURNAL 2007; 5:389-401. [PMID: 17359496 DOI: 10.1111/j.1467-7652.2007.00248.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The highly glycosylated peptide hormone erythropoietin (EPO) plays a key role in the regulation of erythrocyte maturation. Currently, marketed EPO is produced by recombinant technology in mammalian cell cultures. The complementary DNA (cDNA) for human EPO (hEPO) was transiently and stably expressed in the moss Physcomitrella patens wild-type and Delta-fuc-t Delta-xyl-t mutant, the latter containing N-glycans lacking the plant-specific, core-bound alpha1,3-fucose and beta1,2-xylose. New expression vectors were designed based on a Physcomitrella ubiquitin gene-derived promoter for the expression of hEPO cDNA. Transient expression in protoplasts was much stronger at 10 than at 20 degrees C. In Western blot analysis, the molecular size of moss-produced recombinant human EPO (rhEPO) was identified to be 30 kDa, and it accumulated in the medium of transiently transformed protoplasts to high levels around 0.5 microg/mL. Transgenic Physcomitrella Delta-fuc-t Delta-xyl-t mutant lines expressing EPO cDNA showed secretion of rhEPO through the cell wall to the culture medium. In 5- and 10-L photobioreactor cultures, secreted rhEPO accumulated to high levels above 250 microg/g dry weight of moss material after 6 days. Silver staining of rhEPO on sodium dodecylsulphate-polyacrylamide gel electrophoresis (SDS-PAGE) taken from the bioreactor culture demonstrated a high purity of the over-expressed secreted rhEPO, with a very low background of endogenous moss proteins. Peptide mapping of rhEPO produced by the Physcomitrella Delta-fuc-t Delta-xyl-t mutant indicated correct processing of the plant-derived signal peptide. All three N-glycosylation sites of rhEPO were occupied by complex-type N-glycans completely devoid of the plant-specific core sugar residues fucose and xylose.
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Affiliation(s)
- Andreas Weise
- Greenovation Biotech GmbH, Bötzingerstr. 29b, D-79111 Freiburg, Germany
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431
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Kim KI, Sunter G, Bisaro DM, Chung IS. Improved expression of recombinant GFP using a replicating vector based on Beet curly top virus in leaf-disks and infiltrated Nicotiana benthamiana leaves. PLANT MOLECULAR BIOLOGY 2007; 64:103-12. [PMID: 17294255 DOI: 10.1007/s11103-007-9137-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2006] [Accepted: 01/17/2007] [Indexed: 05/13/2023]
Abstract
Recombinant green fluorescent protein (GFP) with a molecular mass of 29 kDa was transiently expressed in Agrobacterium-inoculated leaf-disks prepared from Nicotiana benthamiana plants. Expression of GFP from the Cauliflower mosaic virus (CaMV) 35 S promoter within a replicating vector based on the geminivirus Beet curly top virus (BCTV) was more than 3 times higher than from a control, non-replicating vector. Use of the Cassava vein mosaic virus (CsVMV) promoter in the BCTV replicating vector increased the expression of recombinant GFP 320% at the transcript level, compared to use of the control CaMV 35 S promoter. Expression of recombinant GFP from Agrobacterium-inoculated leaf-disks of N. benthamiana was further enhanced up to 240% in the presence of post-transcriptional gene silencing suppressor p19.
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Affiliation(s)
- Kyung Il Kim
- Graduate School of Biotechnology and Plant Metabolism Research Center, Kyung Hee University, Suwon 449-701, Korea
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432
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Wiley PR, Tosi P, Evrard A, Lovegrove A, Jones HD, Shewry PR. Promoter analysis and immunolocalisation show that puroindoline genes are exclusively expressed in starchy endosperm cells of wheat grain. PLANT MOLECULAR BIOLOGY 2007; 64:125-36. [PMID: 17294254 DOI: 10.1007/s11103-007-9139-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2006] [Accepted: 01/20/2007] [Indexed: 05/13/2023]
Abstract
The purolindolines are small cysteine-rich proteins which are present in the grain of wheat. They have a major impact on the utilisation of the grain as they are the major determinants of grain texture, which affects both milling and baking properties. Bread and durum wheats were transformed with constructs comprising the promoter regions of the Puroindoline a (Pina) and Puroindoline b (Pinb) genes fused to the uidA (GUS) reporter gene. Nine lines showing 3:1 segregation for the transgene and comprising all transgene/species combinations were selected for detailed analysis of transgene expression during grain development. This showed that transgene expression occurred only in the starchy endosperm cells and was not observed in any other seed or vegetative tissues. The location of the puroindoline proteins in these cells was confirmed by tissue printing of developing grain, using a highly specific monoclonal antibody for detection and an antibody to the aleurone-localised 8S globulin as a control. This provides clear evidence that puroindolines are only synthesised and accumulated in the starchy endosperm cells of the wheat grain.
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Affiliation(s)
- Paul R Wiley
- Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
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433
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Wang L, Xu YY, Li J, Powell RA, Xu ZH, Chong K. Transgenic rice plants ectopically expressing AtBAK1 are semi-dwarfed and hypersensitive to 24-epibrassinolide. JOURNAL OF PLANT PHYSIOLOGY 2007; 164:655-64. [PMID: 17027118 DOI: 10.1016/j.jplph.2006.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2006] [Revised: 08/22/2006] [Accepted: 08/25/2006] [Indexed: 05/10/2023]
Abstract
Brassinosteroids (BRs) are endogenous plant hormones essential for plant growth and development. Brassinosteroid insensitive1 (BRI1)-assocaiated receptor kinase (BAK1) is one of the key components in the BR signal transduction pathway due to its direct association with the BR receptor, BRI1. Although BRI1 and its orthologs have been identified from both dicotyledonous and monocotyledonous plants, less is known about BAK1 and its orthologs in higher plants other than Arabidopsis. This article provides the first piece of evidence that AtBAK1 can greatly affect growth and development of rice plants when ectopically expressed, suggesting that rice may share similar BR perception mechanism via BRI1/BAK1 complex. Interestingly, transgenic rice plants displayed semi-dwarfism and shortened primary roots. Physiological analysis and cell morphology assay demonstrated that the observed phenotypes in transgenic plants were presumably caused by hypersensitivity to endogenous levels of BRs, different from BR insensitive and deficient rice mutants. Consistently, several known BR inducible genes were also upregulated in transgenic rice plants, further suggesting that BAK1 was able to affect BR signaling in rice. On the other hand, the transgenic plants generated by overproducing AtBAK1 may potentially have agricultural applications because the dwarfed phenotype is generally resistant to lodging, while the fertility remains unaffected.
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Affiliation(s)
- Lei Wang
- Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, People's Republic of China
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434
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James VA, Neibaur I, Altpeter F. Stress inducible expression of the DREB1A transcription factor from xeric, Hordeum spontaneum L. in turf and forage grass (Paspalum notatum Flugge) enhances abiotic stress tolerance. Transgenic Res 2007; 17:93-104. [PMID: 17415675 DOI: 10.1007/s11248-007-9086-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Accepted: 02/05/2007] [Indexed: 10/23/2022]
Abstract
The dehydration-responsive element binding proteins (DREB1)/C-repeat (CRT) binding factors (CBF) function as transcription activators and bind to the DRE/CRT cis-acting element commonly present in the promoters of abiotic stress-regulated genes. A DREB1A transcription factor ortholog was isolated from a xeric, wild barley (Hordeum spontaneum L.) accession, originating from the Negev desert. Sequence comparison revealed a very high degree of sequence conservation of HsDREB1A to the published barley (Hordeum vulgare L.) DREB1A. Constitutive expression of the HsDREB1A gene was able to trans-activate a reporter gene under transcriptional control of the stress-inducible HVA1s and Dhn8 promoters. HsDREB1A was subcloned under transcriptional control of the stress-inducible barley HVA1s promoter and introduced into the apomictic bahiagrass (Paspalum notatum Flugge) cultivar 'Argentine'. HsDREB1A integration and stress inducible expression was detected in primary transgenic bahiagrass plants and apomictic seed progeny by Southern blot, RT-PCR and northern blot analysis respectively. Transgenic bahiagrass plants with stress-inducible expression of HsDREB1A survived severe salt stress and repeated cycles of severe dehydration stress under controlled environment conditions, in contrast to non-transgenic plants. The observed abiotic stress tolerance is very desirable in turf and forage grasses like bahiagrass, where seasonal droughts and irrigation restrictions affect establishment, persistence or productivity of this perennial crop.
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Affiliation(s)
- Victoria A James
- Agronomy Department, Plant Molecular and Cellular Biology Program, Genetics Institute, University of Florida, PO Box 110300, Gainesville, FL 32611, USA
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435
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Marella HH, Quatrano RS. The B2 domain of VIVIPAROUS1 is bi-functional and regulates nuclear localization and transactivation. PLANTA 2007; 225:863-72. [PMID: 16977453 DOI: 10.1007/s00425-006-0398-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2006] [Accepted: 08/27/2006] [Indexed: 05/11/2023]
Abstract
The transcriptional regulator VIVIPA-ROUS1 (VP1) is composed of four functional domains that control different aspects of gene expression during seed development. The B2 domain is required for its role as a transcriptional activator, functioning at the site of transcription and/or for its transport into the nucleus. Previous work showed that the B2 domain was required for transactivation of the Em promoter. We demonstrate that VP1::GFP localizes to the nucleus of barley (Hordeum vulgare) aleurone cells, but when B2 is deleted, nuclear accumulation is lost. However, the B2 domain itself is not sufficient for nuclear localization of GFP::GUS. Using point mutagenesis on the putative NLS within B2, we show that the VP1::GFP still accumulates in the nucleus. Utilizing a comparative approach, through the alignment of B2 domains from various VP1/ABI3 proteins, oincluding the ABI3 orthologs from Physcomitrella patens, revealed the involvement of other conserved amino acids. Mutating VP1 at the conserved threonine on the N-terminal side of the putative NLS and at a conserved arginine-glutamine-arginine sequence on the C-terminal side prevented nuclear localization of VP1. A single amino acid change, from alanine to threonine, within this NLS found in the Arabidopsis abi3-7 mutant prevents transcription of AtEm1 and AtEm6 in vivo. We show that this same mutation in VP1 prevents transactivation of the Em-GUS reporter in barley aleurone but does not interfere with nuclear localization. Our data demonstrate that the B2 domain of VP1 is bifunctional in nature regulating both nuclear localization and transactivation.
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Affiliation(s)
- Heather H Marella
- Department of Biology, Washington University, 1 Brookings Drive, Campus Box 1137, St Louis, MO 63130, USA
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436
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Blechl A, Lin J, Nguyen S, Chan R, Anderson OD, Dupont FM. Transgenic wheats with elevated levels of Dx5 and/or Dy10 high-molecular-weight glutenin subunits yield doughs with increased mixing strength and tolerance. J Cereal Sci 2007. [DOI: 10.1016/j.jcs.2006.07.009] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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437
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Chong BF, Bonnett GD, Glassop D, O'Shea MG, Brumbley SM. Growth and metabolism in sugarcane are altered by the creation of a new hexose-phosphate sink. PLANT BIOTECHNOLOGY JOURNAL 2007; 5:240-53. [PMID: 17309679 DOI: 10.1111/j.1467-7652.2006.00235.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
An efficient in planta sugarcane-based production system may be realized by coupling the synthesis of alternative products to the metabolic intermediates of sucrose metabolism, thus taking advantage of the sucrose-producing capability of the plant. This was evaluated by synthesizing sorbitol in sugarcane (Saccharum hybrids) using the Malus domestica sorbitol-6-phosphate dehydrogenase gene (mds6pdh). Mature transgenic sugarcane plants were compared with untransformed sugarcane variety Q117 by evaluation of the growth, metabolite levels and extractable activity of relevant enzymes. The average amounts of sorbitol detected in the most productive line were 120 mg/g dry weight (equivalent to 61% of the soluble sugars) in the leaf lamina and 10 mg/g dry weight in the stalk pith. The levels of enzymes involved in sucrose synthesis and cleavage were elevated in the leaves of plants accumulating sorbitol, but this did not affect sucrose accumulation in the culm. The activity of oxidative reactions in the pentose phosphate pathway and the non-reversible glyceraldehyde-3-phosphate dehydrogenase reaction were elevated to replenish the reducing power consumed by sorbitol synthesis. Sorbitol-producing sugarcane generated 30%-40% less aerial biomass and was 10%-30% shorter than control lines. Leaves developed necrosis in a pattern characteristic of early senescence, and the severity was related to the relative quantity of sorbitol accumulated. When the Zymomonas mobilis glucokinase (zmglk) gene was co-expressed with mds6pdh to increase the production of glucose-6-phosphate, the plants were again smaller, indicating that glucose-6-phosphate deficiency was not responsible for the reduced growth. In summary, sorbitol hyperaccumulation affected sugarcane growth and metabolism, but the outcome was not lethal for the plant. This work also demonstrated that impressive yields of alternative products can be generated from the intermediates of sucrose metabolism in Saccharum spp.
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Affiliation(s)
- Barrie Fong Chong
- David North Plant Research Centre, BSES Limited, PO Box 86, Indooroopilly, Qld 4068, Australia.
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438
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Chen R, Zhao X, Shao Z, Wei Z, Wang Y, Zhu L, Zhao J, Sun M, He R, He G. Rice UDP-glucose pyrophosphorylase1 is essential for pollen callose deposition and its cosuppression results in a new type of thermosensitive genic male sterility. THE PLANT CELL 2007; 19:847-61. [PMID: 17400897 PMCID: PMC1867369 DOI: 10.1105/tpc.106.044123] [Citation(s) in RCA: 170] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
UDP-glucose pyrophosphorylase (UGPase) catalyzes the reversible production of glucose-1-phosphate and UTP to UDP-glucose and pyrophosphate. The rice (Oryza sativa) genome contains two homologous UGPase genes, Ugp1 and Ugp2. We report a functional characterization of rice Ugp1, which is expressed throughout the plant, with highest expression in florets, especially in pollen during anther development. Ugp1 silencing by RNA interference or cosuppression results in male sterility. Expressing a double-stranded RNA interference construct in Ugp1-RI plants resulted in complete suppression of both Ugp1 and Ugp2, together with various pleiotropic developmental abnormalities, suggesting that UGPase plays critical roles in plant growth and development. More importantly, Ugp1-cosuppressing plants contained unprocessed intron-containing primary transcripts derived from transcription of the overexpression construct. These aberrant transcripts undergo temperature-sensitive splicing in florets, leading to a novel thermosensitive genic male sterility. Pollen mother cells (PMCs) of Ugp1-silenced plants appeared normal before meiosis, but during meiosis, normal callose deposition was disrupted. Consequently, the PMCs began to degenerate at the early meiosis stage, eventually resulting in complete pollen collapse. In addition, the degeneration of the tapetum and middle layer was inhibited. These results demonstrate that rice Ugp1 is required for callose deposition during PMC meiosis and bridges the apoplastic unloading pathway and pollen development.
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Affiliation(s)
- Rongzhi Chen
- Key Laboratory of Ministry of Education for Plant Developmental Biology, College of Life Sciences, Wuhan University, Wuhan 430072, China
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439
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Shepherd DN, Mangwende T, Martin DP, Bezuidenhout M, Thomson JA, Rybicki EP. Inhibition of maize streak virus (MSV) replication by transient and transgenic expression of MSV replication-associated protein mutants. J Gen Virol 2007; 88:325-336. [PMID: 17170465 DOI: 10.1099/vir.0.82338-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Maize streak disease is a severe agricultural problem in Africa and the development of maize genotypes resistant to the causal agent, Maize streak virus (MSV), is a priority. A transgenic approach to engineering MSV-resistant maize was developed and tested in this study. A pathogen-derived resistance strategy was adopted by using targeted deletions and nucleotide-substitution mutants of the multifunctional MSV replication-associated protein gene (rep). Various rep gene constructs were tested for their efficacy in limiting replication of wild-type MSV by co-bombardment of maize suspension cells together with an infectious genomic clone of MSV and assaying replicative forms of DNA by quantitative PCR. Digitaria sanguinalis, an MSV-sensitive grass species used as a model monocot, was then transformed with constructs that had inhibited virus replication in the transient-expression system. Challenge experiments using leafhopper-transmitted MSV indicated significant MSV resistance--from highly resistant to immune--in regenerated transgenic D. sanguinalis lines. Whereas regenerated lines containing a mutated full-length rep gene displayed developmental and growth defects, those containing a truncated rep gene both were fertile and displayed no growth defects, making the truncated gene a suitable candidate for the development of transgenic MSV-resistant maize.
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Affiliation(s)
- Dionne N Shepherd
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch, Cape Town 7701, South Africa
| | - Tichaona Mangwende
- Division of Pharmacology, University of Cape Town, Cape Town, South Africa
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch, Cape Town 7701, South Africa
| | - Darren P Martin
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, Anzio Road, Cape Town 7925, South Africa
| | - Marion Bezuidenhout
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch, Cape Town 7701, South Africa
| | - Jennifer A Thomson
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch, Cape Town 7701, South Africa
| | - Edward P Rybicki
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, Anzio Road, Cape Town 7925, South Africa
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch, Cape Town 7701, South Africa
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440
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Joensuu JJ, Kotiaho M, Teeri TH, Valmu L, Nuutila AM, Oksman-Caldentey KM, Niklander-Teeri V. Glycosylated F4 (K88) fimbrial adhesin FaeG expressed in barley endosperm induces ETEC-neutralizing antibodies in mice. Transgenic Res 2007; 15:359-73. [PMID: 16779651 DOI: 10.1007/s11248-006-0010-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2005] [Accepted: 02/11/2006] [Indexed: 10/24/2022]
Abstract
The F4-positive enterotoxigenic Escherichia coli (ETEC) strains are a frequent cause of porcine post-weaning diarrhea. Orally administered F4 fimbriae or FaeG, the major subunit and adhesin of F4, induce a protective mucosal immune response in F4 receptor-positive piglets. Feed plants carrying immunogenic subunit proteins can offer great advantages for oral vaccination of domestic animals. Here, we describe high-level endosperm-specific production (1% of total soluble proteins) of FaeG in the crop plant barley. The endoplasmic reticulum-targeted recombinant endospermic FaeG (erFaeG) was shown to be heterogeneously glycosylated. The erFaeG showed resistance at digestive conditions simulating piglet gastric fluid. Glycosylation did not abolish the immunogenic character of the FaeG protein, since erFaeG was able to induce F4 fimbria-specific antibodies in mice. Biological activity of these anti-F4 antibodies was demonstrated in vitro by blocking the attachment of the F4+ ETEC to the F4 receptors present on porcine intestinal enterocytes.
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Affiliation(s)
- Jussi J Joensuu
- Department of Applied Biology, University of Helsinki, P.O. Box 27, FIN-00014, Helsinki, Finland.
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441
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Brereton HM, Chamberlain D, Yang R, Tea M, McNeil S, Coster DJ, Williams KA. Single chain antibody fragments for ocular use produced at high levels in a commercial wheat variety. J Biotechnol 2007; 129:539-46. [PMID: 17306402 DOI: 10.1016/j.jbiotec.2007.01.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2006] [Revised: 12/22/2006] [Accepted: 01/03/2007] [Indexed: 11/18/2022]
Abstract
We are investigating the use of single chain antibody fragments (scFv) in eye drops for diagnosis and treatment of eye diseases. For ocular use, recombinant proteins must be free of bacterial endotoxin that causes inflammation in the eye. We required a means of generating high yields of scFvs with little endotoxin contamination. Using microprojectile bombardment we produced transgenic lines of the commercial wheat variety, Westonia, that express two scFvs that bind to CD4 or CD28 on the surface of rat thymocytes. A high level of expression of active scFv in the range 50-180 microg/g was measured by quantitative flow cytometry in crude extracts made from mature seeds. The levels of expression were stable over four generations of transgenic plants and mature seeds were stored for one year with little loss of scFv activity. Substantial purification of scFv was achieved by immobilised metal affinity chromatography. Compared to bacterial extracts, crude transgenic seed extracts contained only a small amount of endotoxin (150 EU/ml) that will be easily removed by purification. The transgenic wheat lines express functional scFv at levels comparable to production in bacteria and promise to be superior to bacteria for production of scFv pharmaceuticals for ocular use.
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Affiliation(s)
- Helen M Brereton
- Department of Ophthalmology, Flinders University, Adelaide, SA 5042, Australia.
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442
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Takaiwa F, Takagi H, Hirose S, Wakasa Y. Endosperm tissue is good production platform for artificial recombinant proteins in transgenic rice. PLANT BIOTECHNOLOGY JOURNAL 2007; 5:84-92. [PMID: 17207259 DOI: 10.1111/j.1467-7652.2006.00220.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Transgenic rice plants expressing 7Crp peptide were generated by Agrobacterium-mediated transformation. The 7Crp peptide is the hybrid peptide of seven major human T-cell epitopes derived from Japanese cedar pollen allergens Cry j 1 and Cry j 2. When the 7Crp gene was expressed under the control of the rice AGPase large subunit or maize ubiquitin-1 promoters, it could only be detected in the endosperm of rice seed, although high levels of RNA transcript were observed in the leaf, stem, and seed embryo. It was demonstrated by confocal and electron microscopy analysis that the 7Crp peptide was mainly localized in the endoplasmic reticulum-derived protein bodies, designated protein body I (PB-I). Our results indicate that rice endosperm tissue has advantage over other tissues as a production platform for foreign recombinant proteins.
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Affiliation(s)
- Fumio Takaiwa
- Transgenic Crop Research and Development Center, National Institute of Agrobiological Sciences, Kannondai 2-1-2, Tsukuba Ibaraki 305-8602, Japan.
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443
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Wu L, Birch RG. Doubled sugar content in sugarcane plants modified to produce a sucrose isomer. PLANT BIOTECHNOLOGY JOURNAL 2007; 5:109-17. [PMID: 17207261 DOI: 10.1111/j.1467-7652.2006.00224.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Sucrose is the feedstock for more than half of the world's fuel ethanol production and a major human food. It is harvested primarily from sugarcane and beet. Despite attempts through conventional and molecular breeding, the stored sugar concentration in elite sugarcane cultivars has not been increased for several decades. Recently, genes have been cloned for bacterial isomerase enzymes that convert sucrose into sugars which are not metabolized by plants, but which are digested by humans, with health benefits over sucrose. We hypothesized that an appropriate sucrose isomerase (SI) expression pattern might simultaneously provide a valuable source of beneficial sugars and overcome the sugar yield ceiling in plants. The introduction of an SI gene tailored for vacuolar compartmentation resulted in sugarcane lines with remarkable increases in total stored sugar levels. The high-value sugar isomaltulose was accumulated in storage tissues without any decrease in stored sucrose concentration, resulting in up to doubled total sugar concentrations in harvested juice. The lines with enhanced sugar accumulation also showed increased photosynthesis, sucrose transport and sink strength. This remarkable step above the former ceiling in stored sugar concentration provides a new perspective into plant source-sink relationships, and has substantial potential for enhanced food and biofuel production.
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Affiliation(s)
- Luguang Wu
- Botany Department - SIB, The University of Queensland, Brisbane, Qld 4072, Australia
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444
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Petrasovits LA, Purnell MP, Nielsen LK, Brumbley SM. Production of polyhydroxybutyrate in sugarcane. PLANT BIOTECHNOLOGY JOURNAL 2007; 5:162-72. [PMID: 17207265 DOI: 10.1111/j.1467-7652.2006.00229.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
We report here the production of the bacterial polyester, polyhydroxybutyrate (PHB), in the crop species sugarcane (Saccharum spp. hybrids). The PHB biosynthesis enzymes of Ralstonia eutropha [beta-ketothiolase (PHAA), acetoacetyl-reductase (PHAB) and PHB synthase (PHAC)] were expressed in the cytosol or targeted to mitochondria or plastids. PHB accumulated in cytosolic lines at trace amounts, but was not detected in mitochondrial lines. In plastidic lines, PHB accumulated in leaves to a maximum of 1.88% of dry weight without obvious deleterious effects. Epifluorescence and electron microscopy of leaf sections from these lines revealed that PHB granules were visible in plastids of most cell types, except mesophyll cells. The concentration of PHB in culm internodes of plastidic lines was substantially lower than in leaves. Western blot analysis of these lines indicated that expression of the PHB biosynthesis proteins was not limiting in culm internodes. Epifluorescence microscopy of culm internode sections from plastidic lines showed that PHB granules were visible in most cell types, except photosynthetic cortical cells in the rind, and that the lower PHB concentration in culm internodes was probably a result of dilution of PHB-containing cells by the large number of cells with little or no PHB. We discuss strategies for producing PHB in mitochondria and mesophyll cell plastids, and for increasing PHB yields in culms.
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445
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Yao Q, Cong L, He G, Chang J, Li K, Yang G. Optimization of wheat co-transformation procedure with gene cassettes resulted in an improvement in transformation frequency. Mol Biol Rep 2006; 34:61-7. [PMID: 17195929 DOI: 10.1007/s11033-006-9016-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2006] [Accepted: 07/06/2006] [Indexed: 11/29/2022]
Abstract
Genetic manipulation using gene cassettes was applied to the elite wheat variety EM12 via particle bombardment, which allows an improvement in transformation frequency. We simultaneously transferred to wheat immature embryos with two non-linked genes, gus and bar, on either separate gene cassettes or one plasmid. The linear gene cassettes were excised and purified by restriction digestion of the plasmid, and consisted of promoters, open reading frames and terminators. No difference was observed in GUS transient expression of between gene cassettes and single whole plasmid. However, the stable transformation frequency was significantly increased to 1.1% using gene cassettes, compared with 0.4% when using single plasmid. Procedures of the efficient co-transformation with gene cassettes were developed. Factors influencing on the transformation frequency were also studied in order to optimize the procedure. These were acceleration pressure, target distance, gold particle size, the quantity ratio of gene cassettes and the age of target explants. Based on the transient and stable expression of the gus gene cassettes, optimization of transformation parameters improved the reproducibility of transformation in the elite wheat variety.
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Affiliation(s)
- Qin Yao
- China-UK HUST-RRes Genetic Engineering and Genomics Joint Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, 430074, Luoyu Road 1037, Wuhan, Hubei, People's Republic of China
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446
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Nadolska-Orczyk A, Pietrusinska A, Binka-Wyrwa A, Kuc D, Orczyk W. Diploid potato (Solanum tuberosum L.) as a model crop to study transgene expression. Cell Mol Biol Lett 2006; 12:206-19. [PMID: 17160584 PMCID: PMC6275730 DOI: 10.2478/s11658-006-0064-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Accepted: 09/26/2006] [Indexed: 11/20/2022] Open
Abstract
This paper presents a method of Agrobacterium-mediated transformation for two diploid breeding lines of potato, and gives a detailed analysis of reporter gene expression. In our lab, these lines were also used to obtain tetraploid somatic hybrids. We tested four newly prepared constructs based on the pGreen vector system containing the selection gene nptII or bar under the 35S or nos promoter. All these vectors carried gus under 35S. We also tested the pDM805 vector, with the bar and gus genes respectively under the Ubi1 and Act1 promoters, which are strong for monocots. The selection efficiency (about 17%) was highest in the stem and leaf explants after transformation with pGreen where nptII was under 35S. About half of the selected plants were confirmed via PCR and Southern blot analysis to be transgenic and, depending on the combination, 0 to 100% showed GUS expression. GUS expression was strongest in multi-copy transgenic plants where gus was under Act1. The same potato lines carrying multi-copy bar under Ubi1 were also highly resistant to the herbicide Basta. The suggestion of using Agrobacterium-mediated transformation of diploid lines of potato as a model crop is discussed herein.
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Affiliation(s)
- Anna Nadolska-Orczyk
- Plant Transformation and Cell Engineering Department, Plant Breeding and Acclimatization Institute, Radzików, Błonie, Poland.
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447
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Martin JM, Meyer FD, Smidansky ED, Wanjugi H, Blechl AE, Giroux MJ. Complementation of the pina (null) allele with the wild type Pina sequence restores a soft phenotype in transgenic wheat. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2006; 113:1563-70. [PMID: 16988815 DOI: 10.1007/s00122-006-0404-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2006] [Accepted: 08/22/2006] [Indexed: 05/11/2023]
Abstract
The tightly linked puroindoline genes, Pina and Pinb, control grain texture in wheat, with wild type forms of both giving soft, and a sequence alteration affecting protein expression or function in either giving rise to hard wheat. Previous experiments have shown that addition of wild type Pina in the presence of mutated Pinb gave intermediate grain texture but addition of wild type Pinb gave soft grain. This raises questions as to whether Pina may be less functional than Pinb. Our goal here was to develop and characterize wheat lines expressing the wild type Pina-D1a sequence in hard wheat with the null mutation (Pina-D1b) for Pina. Three transgenic lines plus Bobwhite were evaluated in two environments. Grain texture, grain protein, and kernel weight were determined for the transgenic lines and Bobwhite. The three transgenic lines had soft phenotype, and none of the transgenic lines differed from Bobwhite for grain protein or kernel weight. The soft phenotype was accompanied by increases in Pina transcript accumulation. Total Triton X-114 extractable PINA and PINB increased from 2.5 to 5.5 times those from a soft wheat reference sample, and friabilin, PINA and PINB bound to starch, increased from 3.8 to 7.8 times those of the soft wheat reference. Bobwhite showed no starch bound PINA, but transgenic lines had levels from 5.3 to 13.7 times those of the soft wheat reference sample. Starch bound PINB in transgenic lines also increased from 0.9 to 2.5 times that for the soft wheat reference sample. The transgenic expression of wild type Pina sequence in the Pina null genotype gave soft grain with the characteristics of soft wheat including increased starch bound friabilin. The results support the hypothesis that both wild type Pin genes need to be present for friabilin formation and soft grain.
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Affiliation(s)
- J M Martin
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3140, USA.
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448
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Troedsson U, Olsson PA, Jarl-Sunesson CI. Application of antisense transformation of a barley chitinase in studies of arbuscule formation by a mycorrhizal fungus. Hereditas 2006; 142:65-72. [PMID: 16970614 DOI: 10.1111/j.1601-5223.2005.01903.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Barley (Hordeum vulgare L.) plants of two commercial cultivars were transformed with sense and antisense constructs of a chitinase class II gene in order to develop a transformation system for this gene in barley. Transformation of embryos with the two antisense constructs resulted in ten regenerated plants, while no plants could be obtained using the sense construct. The presence of the inserted construct could be confirmed for six of the plants by PCR analysis. This system was used to study the role of class II chitinase in the regulation of mycorrhizal symbiosis. The colonization of two of the antisense transformants by the arbuscular mycorrhizal fungus Glomus intraradices was investigated microscopically and by use of signature fatty acids. The arbuscular incidence increased in transformed barley, and one transformant supported higher extraradical mycelium biomass. It is concluded that antisense transformation of barley could be a useful tool in investigations on the symbiosis between barley and mycorrhizal fungi.
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Affiliation(s)
- U Troedsson
- Lund University, Department of Cell and Organism Biology, Sölvegatan 35B, SE-223 62, Lund, Sweden
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449
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Xu K, Xu X, Fukao T, Canlas P, Maghirang-Rodriguez R, Heuer S, Ismail AM, Bailey-Serres J, Ronald PC, Mackill DJ. Sub1A is an ethylene-response-factor-like gene that confers submergence tolerance to rice. Nature 2006; 442:705-8. [PMID: 16900200 DOI: 10.1038/nature04920] [Citation(s) in RCA: 730] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2006] [Accepted: 05/15/2006] [Indexed: 11/08/2022]
Abstract
Most Oryza sativa cultivars die within a week of complete submergence--a major constraint to rice production in south and southeast Asia that causes annual losses of over US 1 billion dollars and affects disproportionately the poorest farmers in the world. A few cultivars, such as the O. sativa ssp. indica cultivar FR13A, are highly tolerant and survive up to two weeks of complete submergence owing to a major quantitative trait locus designated Submergence 1 (Sub1) near the centromere of chromosome 9 (refs 3, 4, 5-6). Here we describe the identification of a cluster of three genes at the Sub1 locus, encoding putative ethylene response factors. Two of these genes, Sub1B and Sub1C, are invariably present in the Sub1 region of all rice accessions analysed. In contrast, the presence of Sub1A is variable. A survey identified two alleles within those indica varieties that possess this gene: a tolerance-specific allele named Sub1A-1 and an intolerance-specific allele named Sub1A-2. Overexpression of Sub1A-1 in a submergence-intolerant O. sativa ssp. japonica conferred enhanced tolerance to the plants, downregulation of Sub1C and upregulation of Alcohol dehydrogenase 1 (Adh1), indicating that Sub1A-1 is a primary determinant of submergence tolerance. The FR13A Sub1 locus was introgressed into a widely grown Asian rice cultivar using marker-assisted selection. The new variety maintains the high yield and other agronomic properties of the recurrent parent and is tolerant to submergence. Cultivation of this variety is expected to provide protection against damaging floods and increase crop security for farmers.
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MESH Headings
- Alleles
- Chromosomes, Plant/genetics
- Crops, Agricultural/classification
- Crops, Agricultural/drug effects
- Crops, Agricultural/genetics
- Crops, Agricultural/physiology
- Ethylenes/pharmacology
- Genes, Plant/genetics
- Haplotypes
- Molecular Sequence Data
- Oryza/classification
- Oryza/drug effects
- Oryza/genetics
- Oryza/physiology
- Plant Proteins/genetics
- Plant Proteins/metabolism
- Plants, Genetically Modified
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Plant/genetics
- RNA, Plant/metabolism
- Transformation, Genetic
- Water/pharmacology
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Affiliation(s)
- Kenong Xu
- Department of Plant Pathology, University of California, Davis, California 95616, USA
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450
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Meng L, Ziv M, Lemaux PG. Nature of stress and transgene locus influences transgene expression stability in barley. PLANT MOLECULAR BIOLOGY 2006; 62:15-28. [PMID: 16900326 DOI: 10.1007/s11103-006-9000-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2005] [Accepted: 04/06/2006] [Indexed: 05/11/2023]
Abstract
Stress and the nature of the transgene locus can affect transgene expression stability. These effects were studied in two, stably expressing, T6 populations of barley (Hordeum vulgare): bombardment-mediated, multi-copy lines with ubiquitin-driven bar and uidA or single-copy lines from Ds-mediated gene delivery with ubiquitin-driven bar alone. Imposing the environmental stresses, water and nutrient deprivation and heat shock, did not reproducibly affect transgene expression stability; however, high frequencies of heritable transcriptional gene silencing (TGS) occurred following in vitro culture after six generations of stable expression in the multi-copy subline, T3#30, but not in the other lines studied. T3#30 plants with complete TGS had epigenetic modification patterns exactly like those in an identical sibling subline, T3#31, which had significant reduction in transgene expression in the T3 generation and was completely transcriptionally silenced in the absence of imposed stresses in the T6 generation. Complete TGS in T3#30 plants correlated with methylation in the 5'UTR and intron of the ubi1 promoter complex and condensation of chromatin around the transgenes; DNA methylation likely occurred prior to chromatin condensation. Partial TGS in T3#30 also correlated with methylation of the ubi1 promoter complex, as occurred with complete TGS. T3#30 has a complex transgene structure with inverted repeat transgene fragments and a 3'-LTR from a barley retrotransposon, and therefore the transgene locus itself may affect its tendency to silence after in vitro culture and transgene silencing might result from host defense mechanisms activated by changes in plant developmental programming and/or stresses imposed during in vitro growth.
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Affiliation(s)
- Ling Meng
- Department of Plant and Microbial Biology, University of California, 111 Koshland Hall, Berkeley , CA 94720, USA
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