Enhancing gene targeting efficiency in higher plants: rice is on the move

Cotsaftis, Olivier; Guiderdoni, Emmanuel

doi:10.1007/s11248-004-4066-y

Cited by 18 publications

(7 citation statements)

References 143 publications

(140 reference statements)

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“…Exploiting the cellular homologous recombination (HR) machinery, GT allows the exchange of genetic information between homologous DNA sequences and can be used to precisely modify the genome. The integration of transgenes flanked by sequences homologous to the desired genomic insertion site permits efficient and routine gene targeting in prokaryotes and fungi, but GT is very inefficient in higher plants with frequencies of the order of 10 −4 per transformant (Cotsaftis and Guiderdoni, ; Hanin et al ., ; Paszkowski et al ., ).…”

Section: Introductionmentioning

confidence: 99%

Gene targeting in maize by somatic ectopic recombination

Ayar¹,

Wehrkamp-Richter²,

Laffaire

et al. 2012

Plant Biotechnology Journal

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SummaryLow transformation efficiency and high background of non-targeted events are major constraints to gene targeting in plants. We demonstrate here applicability in maize of a system that reduces the constraint from transformation efficiency. The system requires regenerable transformants in which all of the following elements are stably integrated in the genome: (i) donor DNA with the gene of interest adjacent to sequence for repair of a defective selectable marker, (ii) sequence encoding a rare-cutting endonuclease such as I-SceI, (iii) a target locus (TL) comprising the defective selectable marker and I-SceI cleavage site. Typically, this requires additional markers for the integration of the donor and target sequences, which may be assembled through cross-pollination of separate transformants. Inducible expression of I-SceI then cleaves the TL and facilitates homologous recombination, which is assayed by selection for the repaired marker. We used bar and gfp markers to identify assembled transformants, a dexamethasone-inducible I-SceI::GR protein, and selection for recombination events that restored an intact nptII. Applying this strategy to callus permitted the selection of recombination into the TL at a frequency of 0.085% per extracted immature embryo (29% of recombinants). Our results also indicate that excision of the donor locus (DL) through the use of flanking I-SceI cleavage sites may be unnecessary, and a source of unwanted repair events at the DL. The system allows production, from each assembled transformant, of many cells that subsequently can be treated to induce gene targeting. This may facilitate gene targeting in plant species for which transformation efficiencies are otherwise limiting.

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Section: Introductionmentioning

confidence: 99%

Gene targeting in maize by somatic ectopic recombination

Ayar¹,

Wehrkamp-Richter²,

Laffaire

et al. 2012

Plant Biotechnology Journal

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“…Maize Maize was at the forefront of the development of genome editing in cereals, and it is, therefore, useful to consider the different genome editing methods used in this species from a historical perspective before looking at their applications for the modification of agronomic traits. Prior to the development of designer nucleases, targeted mutagenesis was rarely achieved in cereals and the available methods were laborious because they relied on the selection and recovery of extremely rare homologous recombination (HR) events involving an endogenous target and exogenous donor DNA (Cotsaftis and Guiderdoni 2005). An early step toward more efficient GT was the realization that HR is enhanced by the presence of a DSB at the target site, but this created a catch-22 situation in which it was necessary to introduce a DSB at a defined site in order to test whether this would improve the efficiency of targeted transgene insertion by HR.…”

Section: Development Of Genome Editing Techniques In Cerealsmentioning

confidence: 99%

Genome editing in cereal crops: an overview

et al. 2021

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Genome-editing technologies offer unprecedented opportunities for crop improvement with superior precision and speed. This review presents an analysis of the current state of genome editing in the major cereal crops- rice, maize, wheat and barley. Genome editing has been used to achieve important agronomic and quality traits in cereals. These include adaptive traits to mitigate the effects of climate change, tolerance to biotic stresses, higher yields, more optimal plant architecture, improved grain quality and nutritional content, and safer products. Not all traits can be achieved through genome editing, and several technical and regulatory challenges need to be overcome for the technology to realize its full potential. Genome editing, however, has already revolutionized cereal crop improvement and is poised to shape future agricultural practices in conjunction with other breeding innovations.

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“…With the exception of the moss Physcomitrella patens, gene targeting by homologous recombination in plants has a low success rate in the region of 10 -6 which means genuine targeting events must be selected from a large background of random integration events [86]. It has been possible to improve the efficiency of selection by incorporating a strong counterselectable marker in rice and maize [87][88][89]. Site-specific integration in plants has been achieved with the bacterial Cre-loxP system, in which the recombinase target site loxP is integrated by standard methods allowing the subsequent introduction of transgene cassettes at the stable loxP site [90,91].…”

Section: Mitigating Position Effects and Silencingmentioning

confidence: 99%

Optimizing the Yield of Recombinant Pharmaceutical Proteins in Plants

Twyman¹,

Schillberg²,

Fischer

2013

CPD

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The production of recombinant pharmaceutical proteins in plants is entering a new phase with the recent approval of recombinant glucocerebrosidase produced in carrot cells and the successful production of clinical-grade proteins in diverse plant-based production platforms. In the long journey from concept to product, the field of molecular farming has faced technical and economic hurdles, many reflecting the initially limited productivity of plants compared to established platforms such as mammalian cells. This challenge has been met by innovative research aiming to increase recombinant protein yields and maximize the economic benefits of plants. Research has focused on increasing the intrinsic yield capability of plants by optimizing expression construct design, and also on novel strategies to avoid epigenetic silencing and environmental effects on protein accumulation. In this article, we discuss the diverse approaches that have been used to increase the productivity of plant-based platforms for the production of recombinant pharmaceutical proteins and consider future opportunities to maximize the potential of plants and increase their competitiveness outside niche markets.

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Enhancing gene targeting efficiency in higher plants: rice is on the move

Cited by 18 publications

References 143 publications

Gene targeting in maize by somatic ectopic recombination

Gene targeting in maize by somatic ectopic recombination

Genome editing in cereal crops: an overview

Optimizing the Yield of Recombinant Pharmaceutical Proteins in Plants

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