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Sun C, Lei Y, Li B, Gao Q, Li Y, Cao W, Yang C, Li H, Wang Z, Li Y, Wang Y, Liu J, Zhao KT, Gao C. Precise integration of large DNA sequences in plant genomes using PrimeRoot editors. Nat Biotechnol 2024; 42:316-327. [PMID: 37095350 DOI: 10.1038/s41587-023-01769-w] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/28/2023] [Indexed: 04/26/2023]
Abstract
A technique for chromosomal insertion of large DNA segments is much needed in plant breeding and synthetic biology to facilitate the introduction of desired agronomic traits and signaling and metabolic pathways. Here we describe PrimeRoot, a genome editing approach to generate targeted precise large DNA insertions in plants. Third-generation PrimeRoot editors employ optimized prime editing guide RNA designs, an enhanced plant prime editor and superior recombinases to enable precise large DNA insertions of up to 11.1 kilobases into plant genomes. We demonstrate the use of PrimeRoot to accurately introduce gene regulatory elements in rice. In this study, we also integrated a gene cassette comprising PigmR, which confers rice blast resistance driven by an Act1 promoter, into a predicted genomic safe harbor site of Kitaake rice and obtain edited plants harboring the expected insertion with an efficiency of 6.3%. We found that these rice plants have increased blast resistance. These results establish PrimeRoot as a promising approach to precisely insert large segments of DNA in plants.
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Affiliation(s)
- Chao Sun
- State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Genome Editing, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yuan Lei
- State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Genome Editing, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Boshu Li
- State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Genome Editing, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Qiang Gao
- Qi Biodesign, Life Science Park, Beijing, China
| | - Yunjia Li
- State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Genome Editing, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Wen Cao
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory for Monitoring and Green Management of Crop Pests, China Agricultural University, Beijing, China
| | - Chao Yang
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory for Monitoring and Green Management of Crop Pests, China Agricultural University, Beijing, China
| | - Hongchao Li
- State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Genome Editing, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Zhiwei Wang
- Qi Biodesign, Life Science Park, Beijing, China
| | - Yan Li
- Qi Biodesign, Life Science Park, Beijing, China
| | - Yanpeng Wang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Genome Editing, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Jun Liu
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory for Monitoring and Green Management of Crop Pests, China Agricultural University, Beijing, China
| | | | - Caixia Gao
- State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Genome Editing, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, China.
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China.
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Puchta H, Houben A. Plant chromosome engineering - past, present and future. THE NEW PHYTOLOGIST 2024; 241:541-552. [PMID: 37984056 DOI: 10.1111/nph.19414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 10/24/2023] [Indexed: 11/22/2023]
Abstract
Spontaneous chromosomal rearrangements (CRs) play an essential role in speciation, genome evolution and crop domestication. To be able to use the potential of CRs for breeding, plant chromosome engineering was initiated by fragmenting chromosomes by X-ray irradiation. With the rise of the CRISPR/Cas system, it became possible to induce double-strand breaks (DSBs) in a highly efficient manner at will at any chromosomal position. This has enabled a completely new level of predesigned chromosome engineering. The genetic linkage between specific genes can be broken by inducing chromosomal translocations. Natural inversions, which suppress genetic exchange, can be reverted for breeding. In addition, various approaches for constructing minichromosomes by downsizing regular standard A or supernumerary B chromosomes, which could serve as future vectors in plant biotechnology, have been developed. Recently, a functional synthetic centromere could be constructed. Also, different ways of genome haploidization have been set up, some based on centromere manipulations. In the future, we expect to see even more complex rearrangements, which can be combined with previously developed engineering technologies such as recombinases. Chromosome engineering might help to redefine genetic linkage groups, change the number of chromosomes, stack beneficial genes on mini cargo chromosomes, or set up genetic isolation to avoid outcrossing.
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Affiliation(s)
- Holger Puchta
- Joseph Gottlieb Kölreuter Institute for Plant Sciences (JKIP) - Molecular Biology, Karlsruhe Institute of Technology (KIT), 76131, Karlsruhe, Germany
| | - Andreas Houben
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466, Seeland, Germany
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Banu MSA, Huda KMK, Harun-Ur-Rashid M, Parveen S, Tuteja N. A DEAD box helicase Psp68 positively regulates salt stress responses in marker-free transgenic rice plants. Transgenic Res 2023; 32:293-304. [PMID: 37247124 DOI: 10.1007/s11248-023-00353-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 05/16/2023] [Indexed: 05/30/2023]
Abstract
Helicases are the motor proteins not only involved in transcriptional and post-transcription process but also provide abiotic stress tolerance in many crops. The p68, belong to the SF2 (DEAD-box helicase) family proteins and overexpression of Psp68 providing enhanced tolerance to transgenic rice plants. In this study, salinity tolerant marker-free transgenic rice has been developed by overexpressing Psp68 gene and phenotypically characterized. The Psp68 overexpressing marker-free transgenic rice plants were initially screened in the rooting medium containing salt stress and 20% polyethylene glycol (PEG). Stable integration and overexpression of Psp68 in marker-free transgenic lines were confirmed by molecular analyses including PCR, southern, western blot, and qRT-PCR analyses. The marker-free transgenic lines showed enhanced tolerance to salinity stress as displayed by early seed germination, higher chlorophyll content, reduced necrosis, more survival rate, improved seedling growth and more grain yield per plant. Furthermore, Psp68 overexpressing marker-free transgenics also accumulated less Na+ and higher K+ ions in the presence of salinity stress. Phenotypic analyses also revealed that marker-free transgenic rice lines efficiently scavenge ROS-mediated damages as displayed by lower H2O2 and malondialdehyde content, delayed electrolyte leakage, higher photosynthetic efficiency, membrane stability, proline content and enhanced activities of antioxidants enzymes. Overall, our results confirmed that Psp68 overexpression confers salinity stress tolerance in marker-free transgenics, hence the technique could be utilized to develop genetically modified crops without any biosafety issues.
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Affiliation(s)
- Mst Sufara Akhter Banu
- Bangladesh Agricultural Research Council (BARC), Dhaka, 1215, Bangladesh
- Plant Molecular Biology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, Delhi, 110067, India
| | - Kazi Md Kamrul Huda
- Department of Genetics and Plant Breeding, Sher-e-Bangla Agricultural University, Dhaka, 1207, Bangladesh.
- Plant Molecular Biology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, Delhi, 110067, India.
| | - Md Harun-Ur-Rashid
- Department of Genetics and Plant Breeding, Sher-e-Bangla Agricultural University, Dhaka, 1207, Bangladesh
| | - Shahanaz Parveen
- Department of Genetics and Plant Breeding, Sher-e-Bangla Agricultural University, Dhaka, 1207, Bangladesh
| | - Narendra Tuteja
- Plant Molecular Biology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, Delhi, 110067, India
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Abstract
Conventional methods of DNA sequence insertion into plants, using Agrobacterium-mediated transformation or microprojectile bombardment, result in the integration of the DNA at random sites in the genome. These plants may exhibit altered agronomic traits as a consequence of disruption or silencing of genes that serve a critical function. Also, genes of interest inserted at random sites are often not expressed at the desired level. For these reasons, targeted DNA insertion at suitable genomic sites in plants is a desirable alternative. In this paper we review approaches of targeted DNA insertion in plant genomes, discuss current technical challenges, and describe promising applications of targeted DNA insertion for crop genetic improvement.
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Li X, Pan L, Bi D, Tian X, Li L, Xu Z, Wang L, Zou X, Gao X, Yang H, Qu H, Zhao X, Yuan Z, He H, Qu S. Generation of Marker-Free Transgenic Rice Resistant to Rice Blast Disease Using Ac/Ds Transposon-Mediated Transgene Reintegration System. FRONTIERS IN PLANT SCIENCE 2021; 12:644437. [PMID: 33959140 PMCID: PMC8095379 DOI: 10.3389/fpls.2021.644437] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 02/23/2021] [Indexed: 05/14/2023]
Abstract
Rice blast is one of the most serious diseases of rice and a major threat to rice production. Breeding disease-resistant rice is one of the most economical, safe, and effective measures for the control of rice blast. As a complement to traditional crop breeding, the transgenic method can avoid the time-consuming process of crosses and multi-generation selection. In this study, maize (Zea mays) Activator (Ac)/Dissociation (Ds) transposon vectors carrying green fluorescent protein (GFP) and red fluorescent protein (mCherry) genetic markers were used for generating marker-free transgenic rice. Double fluorescent protein-aided counterselection against the presence of T-DNA was performed together with polymerase chain reaction (PCR)-based positive selection for the gene of interest (GOI) to screen marker-free progeny. We cloned an RNAi expression cassette of the rice Pi21 gene that negatively regulates resistance to rice blast as a GOI into the Ds element in the Ac/Ds vector and obtained marker-free T1 rice plants from 13 independent transgenic lines. Marker-free and Ds/GOI-homozygous rice lines were verified by PCR and Southern hybridization analysis to be completely free of transgenic markers and T-DNA sequences. qRT-PCR analysis and rice blast disease inoculation confirmed that the marker-free transgenic rice lines exhibited decreased Pi21 expression levels and increased resistance to rice blast. TAIL-PCR results showed that the Ds (Pi21-RNAi) transgenes in two rice lines were reintegrated in intergenic regions in the rice genome. The Ac/Ds vector with dual fluorescent protein markers offers more reliable screening of marker-free transgenic progeny and can be utilized in the transgenic breeding of rice disease resistance and other agronomic traits.
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Affiliation(s)
- Xin Li
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Longyu Pan
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, China
| | - Dongling Bi
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Xudan Tian
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, China
| | - Lihua Li
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
- College of Plant Protection, Hunan Agricultural University, Changsha, China
| | - Zhaomeng Xu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, China
| | - Lanlan Wang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Xiaowei Zou
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Xiaoqing Gao
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Haihe Yang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Haiyan Qu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Xiangqian Zhao
- Institute of Crop Science and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Zhengjie Yuan
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Haiyan He
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Shaohong Qu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
- *Correspondence: Shaohong Qu, ; orcid.org/0000-0003-2072-122X
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Ramkumar TR, Lenka SK, Arya SS, Bansal KC. A Short History and Perspectives on Plant Genetic Transformation. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2020; 2124:39-68. [PMID: 32277448 DOI: 10.1007/978-1-0716-0356-7_3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Plant genetic transformation is an important technological advancement in modern science, which has not only facilitated gaining fundamental insights into plant biology but also started a new era in crop improvement and commercial farming. However, for many crop plants, efficient transformation and regeneration still remain a challenge even after more than 30 years of technical developments in this field. Recently, FokI endonuclease-based genome editing applications in plants offered an exciting avenue for augmenting crop productivity but it is mainly dependent on efficient genetic transformation and regeneration, which is a major roadblock for implementing genome editing technology in plants. In this chapter, we have outlined the major historical developments in plant genetic transformation for developing biotech crops. Overall, this field needs innovations in plant tissue culture methods for simplification of operational steps for enhancing the transformation efficiency. Similarly, discovering genes controlling developmental reprogramming and homologous recombination need considerable attention, followed by understanding their role in enhancing genetic transformation efficiency in plants. Further, there is an urgent need for exploring new and low-cost universal delivery systems for DNA/RNA and protein into plants. The advancements in synthetic biology, novel vector systems for precision genome editing and gene integration could potentially bring revolution in crop-genetic potential enhancement for a sustainable future. Therefore, efficient plant transformation system standardization across species holds the key for translating advances in plant molecular biology to crop improvement.
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Affiliation(s)
- Thakku R Ramkumar
- Agronomy Department, IFAS, University of Florida, Gainesville, FL, USA
| | - Sangram K Lenka
- TERI-Deakin NanoBiotechnology Centre, The Energy and Resources Institute, New Delhi, India
| | - Sagar S Arya
- TERI-Deakin NanoBiotechnology Centre, The Energy and Resources Institute, New Delhi, India
| | - Kailash C Bansal
- TERI-Deakin NanoBiotechnology Centre, The Energy and Resources Institute, New Delhi, India.
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Pathak BP, Pruett E, Guan H, Srivastava V. Utility of I-SceI and CCR5-ZFN nucleases in excising selectable marker genes from transgenic plants. BMC Res Notes 2019; 12:272. [PMID: 31088537 PMCID: PMC6518718 DOI: 10.1186/s13104-019-4304-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 05/04/2019] [Indexed: 11/21/2022] Open
Abstract
Objectives Removal of selection marker genes from transgenic plants is highly desirable for their regulatory approval and public acceptance. This study evaluated the use of two nucleases, the yeast homing endonuclease, I-SceI, and the designed zinc finger nuclease, CCR5-ZFN, in excising marker genes from plants using rice and Arabidopsis as the models. Results In an in vitro culture assay, both nucleases were effective in precisely excising the DNA fragments marked by the nuclease target sites. However, rice cultures were found to be refractory to transformation with the I-SceI and CCR5-ZFN overexpressing constructs. The inducible I-SceI expression was also problematic in rice as the progeny of the transgenic lines expressing the heat-inducible I-SceI did not inherit the functional gene. On the other hand, heat-inducible I-SceI expression in Arabidopsis was effective in creating somatic excisions in transgenic plants but ineffective in generating heritable excisions. The inducible expression of CCR5-ZFN in rice, although transmitted stably to the progeny, appeared ineffective in creating detectable excisions. Therefore, toxicity of these nucleases in plant cells poses major bottleneck in their application in plant biotechnology, which could be avoided by expressing them transiently in cultures in vitro. Electronic supplementary material The online version of this article (10.1186/s13104-019-4304-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bhuvan P Pathak
- Dept. of Crop, Soil & Environmental Sciences, University of Arkansas, Fayetteville, AR, USA.,Cell and Molecular Biology Program, University of Arkansas, Fayetteville, AR, USA
| | - Eliott Pruett
- Dept. of Crop, Soil & Environmental Sciences, University of Arkansas, Fayetteville, AR, USA.,Cell and Molecular Biology Program, University of Arkansas, Fayetteville, AR, USA
| | - Huazhong Guan
- Dept. of Crop, Soil & Environmental Sciences, University of Arkansas, Fayetteville, AR, USA.,Fujian Provincial Key Laboratory of Crop Breeding, Fujian Agricultural & Forestry University, Fuzhou, China
| | - Vibha Srivastava
- Dept. of Crop, Soil & Environmental Sciences, University of Arkansas, Fayetteville, AR, USA. .,Cell and Molecular Biology Program, University of Arkansas, Fayetteville, AR, USA. .,Dept. of Horticulture, University of Arkansas, Fayetteville, AR, USA.
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Rajaee M, Ow DW. A new location to split Cre recombinase for protein fragment complementation. PLANT BIOTECHNOLOGY JOURNAL 2017; 15:1420-1428. [PMID: 28317293 PMCID: PMC5633763 DOI: 10.1111/pbi.12726] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 03/13/2017] [Accepted: 03/13/2017] [Indexed: 06/06/2023]
Abstract
We have previously described a recombinase-mediated gene stacking system in which the Cre recombinase is used to remove lox-site flanked DNA no longer needed after each round of Bxb1 integrase-mediated site-specific integration. The Cre recombinase can be conveniently introduced by hybridization with a cre-expressing plant. However, maintaining an efficient cre-expressing line over many generations can be a problem, as high production of this DNA-binding protein might interfere with normal chromosome activities. To counter this selection against high Cre activity, we considered a split-cre approach, in which Cre activity is reconstituted after separate parts of Cre are brought into the same genome by hybridization. To insure that the recombinase-mediated gene stacking system retains its freedom to operate, we tested for new locations to split Cre into complementing fragments. In this study, we describe testing four new locations for splitting the Cre recombinase for protein fragment complementation and show that the two fragments of Cre split between Lys244 and Asn245 can reconstitute activity that is comparable to that of wild-type Cre.
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Affiliation(s)
- Maryam Rajaee
- Plant Gene Engineering CenterSouth China Botanical GardenChinese Academy of SciencesGuangzhouChina
- University of Chinese Academy of SciencesBeijingChina
| | - David W. Ow
- Plant Gene Engineering CenterSouth China Botanical GardenChinese Academy of SciencesGuangzhouChina
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Chen W, Ow DW. Precise, flexible and affordable gene stacking for crop improvement. Bioengineered 2017; 8:451-456. [PMID: 28071976 PMCID: PMC5639857 DOI: 10.1080/21655979.2016.1276679] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 12/20/2016] [Indexed: 10/20/2022] Open
Abstract
The genetic engineering of plants offers a revolutionary advance for crop improvement, and the incorporation of transgenes into crop species can impart new traits that would otherwise be difficult to obtain through conventional breeding. Transgenes introduced into plants, however, can only be useful when bred out to field cultivars. As new traits are continually added to further improve transgenic cultivars, clustering new DNA near previously introduced transgenes keep from inflating the number of segregating units that breeders must assemble back into a breeding line. Here we discuss various options to introduce DNA site-specifically into an existing transgenic locus. As food security is becoming a pressing global issue, the old proverb resonates true to this day: "give a man a fish and you feed him for a day; teach a man to fish and you feed him for a lifetime." Hence, we describe a recombinase-mediate gene stacking system designed with freedom to operate, providing an affordable option for crop improvement by less developed countries where food security is most at risk.
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Affiliation(s)
- Weiqiang Chen
- Plant Gene Engineering Center, South China Botanical Garden, Chinese Academy of Science, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - David W. Ow
- Plant Gene Engineering Center, South China Botanical Garden, Chinese Academy of Science, Guangzhou, China
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Xu Y, Li P, Zou C, Lu Y, Xie C, Zhang X, Prasanna BM, Olsen MS. Enhancing genetic gain in the era of molecular breeding. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:2641-2666. [PMID: 28830098 DOI: 10.1093/jxb/erx135] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 04/03/2017] [Indexed: 05/20/2023]
Abstract
As one of the important concepts in conventional quantitative genetics and breeding, genetic gain can be defined as the amount of increase in performance that is achieved annually through artificial selection. To develop pro ducts that meet the increasing demand of mankind, especially for food and feed, in addition to various industrial uses, breeders are challenged to enhance the potential of genetic gain continuously, at ever higher rates, while they close the gaps that remain between the yield potential in breeders' demonstration trials and the actual yield in farmers' fields. Factors affecting genetic gain include genetic variation available in breeding materials, heritability for traits of interest, selection intensity, and the time required to complete a breeding cycle. Genetic gain can be improved through enhancing the potential and closing the gaps, which has been evolving and complemented with modern breeding techniques and platforms, mainly driven by molecular and genomic tools, combined with improved agronomic practice. Several key strategies are reviewed in this article. Favorable genetic variation can be unlocked and created through molecular and genomic approaches including mutation, gene mapping and discovery, and transgene and genome editing. Estimation of heritability can be improved by refining field experiments through well-controlled and precisely assayed environmental factors or envirotyping, particularly for understanding and controlling spatial heterogeneity at the field level. Selection intensity can be significantly heightened through improvements in the scale and precision of genotyping and phenotyping. The breeding cycle time can be shortened by accelerating breeding procedures through integrated breeding approaches such as marker-assisted selection and doubled haploid development. All the strategies can be integrated with other widely used conventional approaches in breeding programs to enhance genetic gain. More transdisciplinary approaches, team breeding, will be required to address the challenge of maintaining a plentiful and safe food supply for future generations. New opportunities for enhancing genetic gain, a high efficiency breeding pipeline, and broad-sense genetic gain are also discussed prospectively.
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Affiliation(s)
- Yunbi Xu
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- International Maize and Wheat Improvement Center (CIMMYT), El Batan, Texcoco, CP 56130, México
| | - Ping Li
- Nantong Xinhe Bio-Technology, Nantong 226019, PR China
| | - Cheng Zou
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yanli Lu
- Maize Research Institute, Sichuan Agricultural University, Wenjiang 611130, Sichuan, China
| | - Chuanxiao Xie
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xuecai Zhang
- International Maize and Wheat Improvement Center (CIMMYT), El Batan, Texcoco, CP 56130, México
| | - Boddupalli M Prasanna
- CIMMYT (International Maize and Wheat Improvement Center), ICRAF campus, United Nations Avenue, Nairobi, Kenya
| | - Michael S Olsen
- CIMMYT (International Maize and Wheat Improvement Center), ICRAF campus, United Nations Avenue, Nairobi, Kenya
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Cardi T, Neal Stewart C. Progress of targeted genome modification approaches in higher plants. PLANT CELL REPORTS 2016; 35:1401-16. [PMID: 27025856 DOI: 10.1007/s00299-016-1975-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 03/21/2016] [Indexed: 05/07/2023]
Abstract
Transgene integration in plants is based on illegitimate recombination between non-homologous sequences. The low control of integration site and number of (trans/cis)gene copies might have negative consequences on the expression of transferred genes and their insertion within endogenous coding sequences. The first experiments conducted to use precise homologous recombination for gene integration commenced soon after the first demonstration that transgenic plants could be produced. Modern transgene targeting categories used in plant biology are: (a) homologous recombination-dependent gene targeting; (b) recombinase-mediated site-specific gene integration; (c) oligonucleotide-directed mutagenesis; (d) nuclease-mediated site-specific genome modifications. New tools enable precise gene replacement or stacking with exogenous sequences and targeted mutagenesis of endogeneous sequences. The possibility to engineer chimeric designer nucleases, which are able to target virtually any genomic site, and use them for inducing double-strand breaks in host DNA create new opportunities for both applied plant breeding and functional genomics. CRISPR is the most recent technology available for precise genome editing. Its rapid adoption in biological research is based on its inherent simplicity and efficacy. Its utilization, however, depends on available sequence information, especially for genome-wide analysis. We will review the approaches used for genome modification, specifically those for affecting gene integration and modification in higher plants. For each approach, the advantages and limitations will be noted. We also will speculate on how their actual commercial development and implementation in plant breeding will be affected by governmental regulations.
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Affiliation(s)
- Teodoro Cardi
- Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria (CREA), Centro di Ricerca per l'Orticoltura, Via Cavalleggeri 25, 84098, Pontecagnano, Italy.
| | - C Neal Stewart
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
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Petolino JF, Srivastava V, Daniell H. Editing Plant Genomes: a new era of crop improvement. PLANT BIOTECHNOLOGY JOURNAL 2016; 14:435-6. [PMID: 26817702 DOI: 10.1111/pbi.12542] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
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