1
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Tian J, Wang C, Chen F, Qin W, Yang H, Zhao S, Xia J, Du X, Zhu Y, Wu L, Cao Y, Li H, Zhuang J, Chen S, Zhang H, Chen Q, Zhang M, Deng XW, Deng D, Li J, Tian F. Maize smart-canopy architecture enhances yield at high densities. Nature 2024; 632:576-584. [PMID: 38866052 DOI: 10.1038/s41586-024-07669-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 06/04/2024] [Indexed: 06/14/2024]
Abstract
Increasing planting density is a key strategy for enhancing maize yields1-3. An ideotype for dense planting requires a 'smart canopy' with leaf angles at different canopy layers differentially optimized to maximize light interception and photosynthesis4-6, among other features. Here we identified leaf angle architecture of smart canopy 1 (lac1), a natural mutant with upright upper leaves, less erect middle leaves and relatively flat lower leaves. lac1 has improved photosynthetic capacity and attenuated responses to shade under dense planting. lac1 encodes a brassinosteroid C-22 hydroxylase that predominantly regulates upper leaf angle. Phytochrome A photoreceptors accumulate in shade and interact with the transcription factor RAVL1 to promote its degradation via the 26S proteasome, thereby inhibiting activation of lac1 by RAVL1 and decreasing brassinosteroid levels. This ultimately decreases upper leaf angle in dense fields. Large-scale field trials demonstrate that lac1 boosts maize yields under high planting densities. To quickly introduce lac1 into breeding germplasm, we transformed a haploid inducer and recovered homozygous lac1 edits from 20 diverse inbred lines. The tested doubled haploids uniformly acquired smart-canopy-like plant architecture. We provide an important target and an accelerated strategy for developing high-density-tolerant cultivars, with lac1 serving as a genetic chassis for further engineering of a smart canopy in maize.
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Affiliation(s)
- Jinge Tian
- State Key Laboratory of Plant Environmental Resilience, Frontiers Science Center for Molecular Design Breeding, National Maize Improvement Center, Center for Crop Functional Genomics and Molecular Breeding, Key Laboratory of Biology and Genetic Improvement of Maize (MOA), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China
- Maize Research Institute, Beijing Academy of Agriculture and Forestry Sciences (BAAFS), Beijing, China
| | - Chenglong Wang
- State Key Laboratory of Plant Environmental Resilience, Frontiers Science Center for Molecular Design Breeding, National Maize Improvement Center, Center for Crop Functional Genomics and Molecular Breeding, Key Laboratory of Biology and Genetic Improvement of Maize (MOA), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China
| | - Fengyi Chen
- State Key Laboratory of Plant Environmental Resilience, Frontiers Science Center for Molecular Design Breeding, National Maize Improvement Center, Center for Crop Functional Genomics and Molecular Breeding, Key Laboratory of Biology and Genetic Improvement of Maize (MOA), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China
| | - Wenchao Qin
- State Key Laboratory of Plant Environmental Resilience, Frontiers Science Center for Molecular Design Breeding, National Maize Improvement Center, Center for Crop Functional Genomics and Molecular Breeding, Key Laboratory of Biology and Genetic Improvement of Maize (MOA), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China
| | - Hong Yang
- State Key Laboratory of Plant Environmental Resilience, Frontiers Science Center for Molecular Design Breeding, National Maize Improvement Center, Center for Crop Functional Genomics and Molecular Breeding, Key Laboratory of Biology and Genetic Improvement of Maize (MOA), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China
| | - Sihang Zhao
- Sanya Institute of China Agricultural University, Sanya, China
| | - Jinliang Xia
- State Key Laboratory of Plant Environmental Resilience, Frontiers Science Center for Molecular Design Breeding, National Maize Improvement Center, Center for Crop Functional Genomics and Molecular Breeding, Key Laboratory of Biology and Genetic Improvement of Maize (MOA), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China
| | - Xian Du
- State Key Laboratory of Plant Environmental Resilience, Frontiers Science Center for Molecular Design Breeding, National Maize Improvement Center, Center for Crop Functional Genomics and Molecular Breeding, Key Laboratory of Biology and Genetic Improvement of Maize (MOA), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China
| | - Yifan Zhu
- State Key Laboratory of Plant Environmental Resilience, Frontiers Science Center for Molecular Design Breeding, National Maize Improvement Center, Center for Crop Functional Genomics and Molecular Breeding, Key Laboratory of Biology and Genetic Improvement of Maize (MOA), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China
| | - Lishuan Wu
- State Key Laboratory of Plant Environmental Resilience, Frontiers Science Center for Molecular Design Breeding, National Maize Improvement Center, Center for Crop Functional Genomics and Molecular Breeding, Key Laboratory of Biology and Genetic Improvement of Maize (MOA), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China
| | - Yan Cao
- State Key Laboratory of Plant Environmental Resilience, Center for Crop Functional Genomics and Molecular Breeding, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Hong Li
- State Key Laboratory of Plant Environmental Resilience, Center for Crop Functional Genomics and Molecular Breeding, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Junhong Zhuang
- State Key Laboratory of Plant Environmental Resilience, Center for Crop Functional Genomics and Molecular Breeding, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Shaojiang Chen
- National Maize Improvement Center of China, Key Laboratory of Crop Heterosis and Utilization (MOE), China Agricultural University, Beijing, China
| | | | - Qiuyue Chen
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC, USA
| | - Mingcai Zhang
- State Key Laboratory of Plant Environmental Resilience, Engineering Research Center of Plant Growth Regulator, Ministry of Education, College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Xing Wang Deng
- Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences at Weifang, Weifang, China
| | | | - Jigang Li
- State Key Laboratory of Plant Environmental Resilience, Center for Crop Functional Genomics and Molecular Breeding, College of Biological Sciences, China Agricultural University, Beijing, China.
| | - Feng Tian
- State Key Laboratory of Plant Environmental Resilience, Frontiers Science Center for Molecular Design Breeding, National Maize Improvement Center, Center for Crop Functional Genomics and Molecular Breeding, Key Laboratory of Biology and Genetic Improvement of Maize (MOA), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China.
- Sanya Institute of China Agricultural University, Sanya, China.
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2
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Yang N, Wang Y, Liu X, Jin M, Vallebueno-Estrada M, Calfee E, Chen L, Dilkes BP, Gui S, Fan X, Harper TK, Kennett DJ, Li W, Lu Y, Ding J, Chen Z, Luo J, Mambakkam S, Menon M, Snodgrass S, Veller C, Wu S, Wu S, Zhuo L, Xiao Y, Yang X, Stitzer MC, Runcie D, Yan J, Ross-Ibarra J. Two teosintes made modern maize. Science 2023; 382:eadg8940. [PMID: 38033071 DOI: 10.1126/science.adg8940] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 10/02/2023] [Indexed: 12/02/2023]
Abstract
The origins of maize were the topic of vigorous debate for nearly a century, but neither the current genetic model nor earlier archaeological models account for the totality of available data, and recent work has highlighted the potential contribution of a wild relative, Zea mays ssp. mexicana. Our population genetic analysis reveals that the origin of modern maize can be traced to an admixture between ancient maize and Zea mays ssp. mexicana in the highlands of Mexico some 4000 years after domestication began. We show that variation in admixture is a key component of maize diversity, both at individual loci and for additive genetic variation underlying agronomic traits. Our results clarify the origin of modern maize and raise new questions about the anthropogenic mechanisms underlying dispersal throughout the Americas.
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Affiliation(s)
- Ning Yang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- Hubei Hongshan Laboratory, Wuhan 430070, China
- Department of Evolution and Ecology, University of California, Davis, CA 95616, USA
| | - Yuebin Wang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Xiangguo Liu
- Institute of Agricultural Biotechnology, Jilin Academy of Agricultural Sciences, Changchun 130033, China
| | - Minliang Jin
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Miguel Vallebueno-Estrada
- Unidad de Genómica Avanzada, Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV Irapuato, 36821 Guanajuato, México
| | - Erin Calfee
- Department of Evolution and Ecology, University of California, Davis, CA 95616, USA
- Center for Population Biology, University of California, Davis, CA 95616, USA
- Adaptive Biotechnologies, Seattle, WA 98109, USA
| | - Lu Chen
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Brian P Dilkes
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Songtao Gui
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Xingming Fan
- Institute of Food Crops, Yunnan Academy of Agricultural Sciences, Kunming 650200, China
| | - Thomas K Harper
- Department of Anthropology, Pennsylvania State University, University Park, PA 16802, USA
| | - Douglas J Kennett
- Department of Anthropology, University of California, Santa Barbara, CA 93106, USA
| | - Wenqiang Li
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Yanli Lu
- Maize Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan 611130, China
| | - Junqiang Ding
- College of Agronomy, Henan Agricultural University, Zhengzhou, Henan 450046, China
| | - Ziqi Chen
- Institute of Agricultural Biotechnology, Jilin Academy of Agricultural Sciences, Changchun 130033, China
| | - Jingyun Luo
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Sowmya Mambakkam
- Department of Evolution and Ecology, University of California, Davis, CA 95616, USA
| | - Mitra Menon
- Department of Evolution and Ecology, University of California, Davis, CA 95616, USA
- Center for Population Biology, University of California, Davis, CA 95616, USA
| | - Samantha Snodgrass
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - Carl Veller
- Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637, USA
| | - Shenshen Wu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Siying Wu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Lin Zhuo
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Yingjie Xiao
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- Hubei Hongshan Laboratory, Wuhan 430070, China
| | - Xiaohong Yang
- National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China
| | - Michelle C Stitzer
- Institute for Genomic Diversity and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Daniel Runcie
- Department of Plant Sciences, University of California, Davis, CA 95616, USA
| | - Jianbing Yan
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- Hubei Hongshan Laboratory, Wuhan 430070, China
- Yazhouwan National Laboratory, Sanya 572024, China
| | - Jeffrey Ross-Ibarra
- Department of Evolution and Ecology, University of California, Davis, CA 95616, USA
- Center for Population Biology, University of California, Davis, CA 95616, USA
- Genome Center, University of California, Davis, CA 95616, USA
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3
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McFarland FL, Collier R, Walter N, Martinell B, Kaeppler SM, Kaeppler HF. A key to totipotency: Wuschel-like homeobox 2a unlocks embryogenic culture response in maize (Zea mays L.). PLANT BIOTECHNOLOGY JOURNAL 2023; 21:1860-1872. [PMID: 37357571 PMCID: PMC10440991 DOI: 10.1111/pbi.14098] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 06/19/2023] [Accepted: 05/28/2023] [Indexed: 06/27/2023]
Abstract
The ability of plant somatic cells to dedifferentiate, form somatic embryos and regenerate whole plants in vitro has been harnessed for both clonal propagation and as a key component of plant genetic engineering systems. Embryogenic culture response is significantly limited, however, by plant genotype in most species. This impedes advancements in both plant transformation-based functional genomics research and crop improvement efforts. We utilized natural variation among maize inbred lines to genetically map somatic embryo generation potential in tissue culture and identify candidate genes underlying totipotency. Using a series of maize lines derived from crosses involving the culturable parent A188 and the non-responsive parent B73, we identified a region on chromosome 3 associated with embryogenic culture response and focused on three candidate genes within the region based on genetic position and expression pattern. Two candidate genes showed no effect when ectopically expressed in B73, but the gene Wox2a was found to induce somatic embryogenesis and embryogenic callus proliferation. Transgenic B73 cells with strong constitutive expression of the B73 and A188 coding sequences of Wox2a were found to produce somatic embryos at similar frequencies, demonstrating that sufficient expression of either allele could rescue the embryogenic culture phenotype. Transgenic B73 plants were regenerated from the somatic embryos without chemical selection and no pleiotropic effects were observed in the Wox2a overexpression lines in the regenerated T0 plants or in the two independent events which produced T1 progeny. In addition to linking natural variation in tissue culture response to Wox2a, our data support the utility of Wox2a in enabling transformation of recalcitrant genotypes.
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Affiliation(s)
- Frank L. McFarland
- Department of AgronomyUniversity of WisconsinMadisonWIUSA
- Wisconsin Crop Innovation CenterUniversity of WisconsinMiddletonWIUSA
| | - Ray Collier
- Department of AgronomyUniversity of WisconsinMadisonWIUSA
| | | | | | - Shawn M. Kaeppler
- Department of AgronomyUniversity of WisconsinMadisonWIUSA
- Wisconsin Crop Innovation CenterUniversity of WisconsinMiddletonWIUSA
| | - Heidi F. Kaeppler
- Department of AgronomyUniversity of WisconsinMadisonWIUSA
- Wisconsin Crop Innovation CenterUniversity of WisconsinMiddletonWIUSA
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4
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Bekalu ZE, Panting M, Bæksted Holme I, Brinch-Pedersen H. Opportunities and Challenges of In Vitro Tissue Culture Systems in the Era of Crop Genome Editing. Int J Mol Sci 2023; 24:11920. [PMID: 37569295 PMCID: PMC10419073 DOI: 10.3390/ijms241511920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 07/17/2023] [Accepted: 07/21/2023] [Indexed: 08/13/2023] Open
Abstract
Currently, the development of genome editing (GE) tools has provided a wide platform for targeted modification of plant genomes. However, the lack of versatile DNA delivery systems for a large variety of crop species has been the main bottleneck for improving crops with beneficial traits. Currently, the generation of plants with heritable mutations induced by GE tools mostly goes through tissue culture. Unfortunately, current tissue culture systems restrict successful results to only a limited number of plant species and genotypes. In order to release the full potential of the GE tools, procedures need to be species and genotype independent. This review provides an in-depth summary and insights into the various in vitro tissue culture systems used for GE in the economically important crops barley, wheat, rice, sorghum, soybean, maize, potatoes, cassava, and millet and uncovers new opportunities and challenges of already-established tissue culture platforms for GE in the crops.
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5
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Lee K, Kang M, Ji Q, Grosic S, Wang K. New T-DNA binary vectors with NptII selection and RUBY reporter for efficient maize transformation and targeted mutagenesis. PLANT PHYSIOLOGY 2023:kiad231. [PMID: 37070560 DOI: 10.1093/plphys/kiad231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 04/03/2023] [Accepted: 04/17/2023] [Indexed: 06/19/2023]
Affiliation(s)
- Keunsub Lee
- Department of Agronomy, Iowa State University, Ames, Iowa, USA
- Crop Bioengineering Center, Iowa State University, Ames, Iowa, USA
| | - Minjeong Kang
- Department of Agronomy, Iowa State University, Ames, Iowa, USA
- Crop Bioengineering Center, Iowa State University, Ames, Iowa, USA
- Interdepartmental Plant Biology Major, Iowa State, University, Ames, Iowa, USA
| | - Qing Ji
- Crop Bioengineering Center, Iowa State University, Ames, Iowa, USA
| | - Sehiza Grosic
- Crop Bioengineering Center, Iowa State University, Ames, Iowa, USA
| | - Kan Wang
- Department of Agronomy, Iowa State University, Ames, Iowa, USA
- Crop Bioengineering Center, Iowa State University, Ames, Iowa, USA
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6
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Aesaert S, Impens L, Coussens G, Van Lerberge E, Vanderhaeghen R, Desmet L, Vanhevel Y, Bossuyt S, Wambua AN, Van Lijsebettens M, Inzé D, De Keyser E, Jacobs TB, Karimi M, Pauwels L. Optimized Transformation and Gene Editing of the B104 Public Maize Inbred by Improved Tissue Culture and Use of Morphogenic Regulators. FRONTIERS IN PLANT SCIENCE 2022; 13:883847. [PMID: 35528934 PMCID: PMC9072829 DOI: 10.3389/fpls.2022.883847] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 03/22/2022] [Indexed: 05/13/2023]
Abstract
Plant transformation is a bottleneck for the application of gene editing in plants. In Zea mays (maize), a breakthrough was made using co-transformation of the morphogenic transcription factors BABY BOOM (BBM) and WUSCHEL (WUS) to induce somatic embryogenesis. Together with adapted tissue culture media, this was shown to increase transformation efficiency significantly. However, use of the method has not been reported widely, despite a clear need for increased transformation capacity in academic settings. Here, we explore use of the method for the public maize inbred B104 that is widely used for transformation by the research community. We find that only modifying tissue culture media already boosts transformation efficiency significantly and can reduce the time in tissue culture by 1 month. On average, production of independent transgenic plants per starting embryo increased from 1 to 4% using BIALAPHOS RESISTANCE (BAR) as a selection marker. In addition, we reconstructed the BBM-WUS morphogenic gene cassette and evaluated its functionality in B104. Expression of the morphogenic genes under tissue- and development stage-specific promoters led to direct somatic embryo formation on the scutellum of zygotic embryos. However, eight out of ten resulting transgenic plants showed pleiotropic developmental defects and were not fertile. This undesirable phenotype was positively correlated with the copy number of the morphogenic gene cassette. Use of constructs in which morphogenic genes are flanked by a developmentally controlled Cre/LoxP recombination system led to reduced T-DNA copy number and fertile T0 plants, while increasing transformation efficiency from 1 to 5% using HIGHLY-RESISTANT ACETOLACTATE SYNTHASE as a selection marker. Addition of a CRISPR/Cas9 module confirmed functionality for gene editing applications, as exemplified by editing the gene VIRESCENT YELLOW-LIKE (VYL) that can act as a visual marker for gene editing in maize. The constructs, methods, and insights produced in this work will be valuable to translate the use of BBM-WUS and other emerging morphogenic regulators (MRs) to other genotypes and crops.
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Affiliation(s)
- Stijn Aesaert
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Lennert Impens
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Griet Coussens
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Els Van Lerberge
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Rudy Vanderhaeghen
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Laurence Desmet
- Plant Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Melle, Belgium
| | - Yasmine Vanhevel
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Shari Bossuyt
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Angeline Ndele Wambua
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Mieke Van Lijsebettens
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Dirk Inzé
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Ellen De Keyser
- Plant Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Melle, Belgium
| | - Thomas B. Jacobs
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Mansour Karimi
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Laurens Pauwels
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
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7
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Kang M, Lee K, Finley T, Chappell H, Veena V, Wang K. An Improved Agrobacterium-Mediated Transformation and Genome-Editing Method for Maize Inbred B104 Using a Ternary Vector System and Immature Embryos. FRONTIERS IN PLANT SCIENCE 2022; 13:860971. [PMID: 35599865 PMCID: PMC9114882 DOI: 10.3389/fpls.2022.860971] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/07/2022] [Indexed: 05/17/2023]
Abstract
For maize genome-editing and bioengineering, genetic transformation of inbred genotypes is most desired due to the uniformity of genetic background in their progenies. However, most maize inbred lines are recalcitrant to tissue culture and transformation. A public, transformable maize inbred B104 has been widely used for genome editing in recent years. This is primarily due to its high degree of genetic similarity shared with B73, an inbred of the reference genome and parent of many breeding populations. Conventional B104 maize transformation protocol requires 16-22 weeks to produce rooted transgenic plants with an average of 4% transformation frequency (number of T0 plants per 100 infected embryos). In this Method paper, we describe an advanced B104 transformation protocol that requires only 7-10 weeks to generate transgenic plants with an average of 6.4% transformation frequency. Over 66% of transgenic plants carried CRISPR/Cas9-induced indel mutations on the target gene, demonstrating that this protocol can be used for genome editing applications. Following the detailed and stepwise procedure described here, this quick and simplified method using the Agrobacterium ternary vector system consisting of a T-DNA binary vector and a compatible helper plasmid can be readily transferable to interested researchers.
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Affiliation(s)
- Minjeong Kang
- Department of Agronomy, Iowa State University, Ames, IA, United States
- Crop Bioengineering Center, Iowa State University, Ames, IA, United States
- Interdepartmental Plant Biology Major, Iowa State University, Ames, IA, United States
| | - Keunsub Lee
- Department of Agronomy, Iowa State University, Ames, IA, United States
- Crop Bioengineering Center, Iowa State University, Ames, IA, United States
| | - Todd Finley
- Plant Transformation Facility, Donald Danforth Plant Science Center, St. Louis, MO, United States
| | - Hal Chappell
- Plant Transformation Facility, Donald Danforth Plant Science Center, St. Louis, MO, United States
| | - Veena Veena
- Plant Transformation Facility, Donald Danforth Plant Science Center, St. Louis, MO, United States
- Veena Veena,
| | - Kan Wang
- Department of Agronomy, Iowa State University, Ames, IA, United States
- Crop Bioengineering Center, Iowa State University, Ames, IA, United States
- *Correspondence: Kan Wang,
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8
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Resistance to Aflatoxin Accumulation in Maize Mediated by Host-Induced Silencing of the Aspergillus flavus Alkaline Protease ( alk) Gene. J Fungi (Basel) 2021; 7:jof7110904. [PMID: 34829193 PMCID: PMC8622731 DOI: 10.3390/jof7110904] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 10/21/2021] [Accepted: 10/23/2021] [Indexed: 12/29/2022] Open
Abstract
Aspergillus flavus is a fungal pathogen that infects maize and produces aflatoxins. Host-Induced Gene Silencing (HIGS) has been shown to reduce host infection by various fungal pathogens. Here, the A. flavus alkaline protease (alk) gene was targeted for silencing through HIGS. An RNAi vector carrying a portion of the alk gene was incorporated into the B104 maize genome. Four out of eight transformation events containing the alk gene, Alk-3, Alk-4, Alk-7 and Alk-9, were self-pollinated to T4/T6 generations. At T3, the Alk-transgenic lines showed up to 87% reduction in aflatoxin accumulation under laboratory conditions. T4 transgenic Alk-3 and Alk-7 lines, and T5 and T6 Alk-4 and Alk-9 showed an average of 84% reduction in aflatoxin accumulation compared to their null controls under field inoculations (p < 0.05). F1 hybrids of three elite maize inbred lines and the transgenic lines also showed significant improvement in aflatoxin resistance (p < 0.006 to p < 0.045). Reduced A. flavus growth and levels of fungal ß-tubulin DNA were observed in transgenic kernels during in vitro inoculation. Alk-4 transgenic leaf and immature kernel tissues also contained about 1000-fold higher levels of alk-specific small RNAs compared to null controls, indicating that the enhanced aflatoxin resistance in the transgenic maize kernels is due to suppression of A. flavus infection through HIGS of alk gene.
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9
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Ahmar S, Mahmood T, Fiaz S, Mora-Poblete F, Shafique MS, Chattha MS, Jung KH. Advantage of Nanotechnology-Based Genome Editing System and Its Application in Crop Improvement. FRONTIERS IN PLANT SCIENCE 2021; 12:663849. [PMID: 34122485 PMCID: PMC8194497 DOI: 10.3389/fpls.2021.663849] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 04/26/2021] [Indexed: 05/05/2023]
Abstract
Agriculture is an important source of human food. However, current agricultural practices need modernizing and strengthening to fulfill the increasing food requirements of the growing worldwide population. Genome editing (GE) technology has been used to produce plants with improved yields and nutritional value as well as with higher resilience to herbicides, insects, and diseases. Several GE tools have been developed recently, including clustered regularly interspaced short palindromic repeats (CRISPR) with nucleases, a customizable and successful method. The main steps of the GE process involve introducing transgenes or CRISPR into plants via specific gene delivery systems. However, GE tools have certain limitations, including time-consuming and complicated protocols, potential tissue damage, DNA incorporation in the host genome, and low transformation efficiency. To overcome these issues, nanotechnology has emerged as a groundbreaking and modern technique. Nanoparticle-mediated gene delivery is superior to conventional biomolecular approaches because it enhances the transformation efficiency for both temporal (transient) and permanent (stable) genetic modifications in various plant species. However, with the discoveries of various advanced technologies, certain challenges in developing a short-term breeding strategy in plants remain. Thus, in this review, nanobased delivery systems and plant genetic engineering challenges are discussed in detail. Moreover, we have suggested an effective method to hasten crop improvement programs by combining current technologies, such as speed breeding and CRISPR/Cas, with nanotechnology. The overall aim of this review is to provide a detailed overview of nanotechnology-based CRISPR techniques for plant transformation and suggest applications for possible crop enhancement.
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Affiliation(s)
- Sunny Ahmar
- Institute of Biological Sciences, Universidad de Talca, Talca, Chile
| | - Tahir Mahmood
- Chinese Academy of Agricultural Sciences, Beijing, China
| | - Sajid Fiaz
- Department of Plant Breeding and Genetics, The University of Haripur, Haripur, Pakistan
| | | | | | | | - Ki-Hung Jung
- Graduate School of Biotechnology & Crop Biotech Institute, Kyung Hee University, Yongin, South Korea
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10
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Koester RP, Pignon CP, Kesler DC, Willison RS, Kang M, Shen Y, Priest HD, Begemann MB, Cook KA, Bannon GA, Oufattole M. Transgenic insertion of the cyanobacterial membrane protein ictB increases grain yield in Zea mays through increased photosynthesis and carbohydrate production. PLoS One 2021; 16:e0246359. [PMID: 33539477 PMCID: PMC7861388 DOI: 10.1371/journal.pone.0246359] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 01/18/2021] [Indexed: 11/19/2022] Open
Abstract
The C4 crop maize (Zea mays) is the most widely grown cereal crop worldwide and is an essential feedstock for food and bioenergy. Improving maize yield is important to achieve food security and agricultural sustainability in the 21st century. One potential means to improve crop productivity is to enhance photosynthesis. ictB, a membrane protein that is highly conserved across cyanobacteria, has been shown to improve photosynthesis, and often biomass, when introduced into diverse C3 plant species. Here, ictB from Synechococcus sp. strain PCC 7942 was inserted into maize using Agrobacterium-mediated transformation. In three controlled-environment experiments, ictB insertion increased leaf starch and sucrose content by up to 25% relative to controls. Experimental field trials in four growing seasons, spanning the Midwestern United States (Summers 2018 & 2019) and Argentina (Winter 2018 & 2019), showed an average of 3.49% grain yield improvement, by as much as 5.4% in a given season and up to 9.4% at certain trial locations. A subset of field trial locations was used to test for modification of ear traits and ФPSII, a proxy for photosynthesis. Results suggested that yield gain in transgenics could be associated with increased ФPSII, and the production of longer, thinner ears with more kernels. ictB localized primarily to the microsome fraction of leaf bundle-sheath cells, but not to chloroplasts. Extramembrane domains of ictB interacted in vitro with proteins involved in photosynthesis and carbohydrate metabolism. To our knowledge, this is the first published evidence of ictB insertion into a species using C4 photosynthesis and the largest-scale demonstration of grain yield enhancement from ictB insertion in planta. Results show that ictB is a valuable yield gene in the economically important crop maize, and are an important proof of concept that transgenic manipulation of photosynthesis can be used to create economically viable crop improvement traits.
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Affiliation(s)
| | | | - Dylan C Kesler
- Benson Hill, St. Louis, Missouri, United States of America
| | | | - Miyoung Kang
- Benson Hill, St. Louis, Missouri, United States of America
| | - Yu Shen
- Benson Hill, St. Louis, Missouri, United States of America
| | - Henry D Priest
- Benson Hill, St. Louis, Missouri, United States of America
| | | | - Kevin A Cook
- Benson Hill, St. Louis, Missouri, United States of America
| | - Gary A Bannon
- Benson Hill, St. Louis, Missouri, United States of America
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11
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McCaw ME, Lee K, Kang M, Zobrist JD, Azanu MK, Birchler JA, Wang K. Development of a Transformable Fast-Flowering Mini-Maize as a Tool for Maize Gene Editing. Front Genome Ed 2021; 2:622227. [PMID: 34713243 PMCID: PMC8525386 DOI: 10.3389/fgeed.2020.622227] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 11/26/2020] [Indexed: 11/13/2022] Open
Abstract
Maize (Zea mays ssp. mays) is a popular genetic model due to its ease of crossing, well-established toolkits, and its status as a major global food crop. Recent technology developments for precise manipulation of the genome are further impacting both basic biological research and biotechnological application in agriculture. Crop gene editing often requires a process of genetic transformation in which the editing reagents are introduced into plant cells. In maize, this procedure is well-established for a limited number of public lines that are amenable for genetic transformation. Fast-Flowering Mini-Maize (FFMM) lines A and B were recently developed as an open-source tool for maize research by reducing the space requirements and the generation time. Neither line of FFMM were competent for genetic transformation using traditional protocols, a necessity to its status as a complete toolkit for public maize genetic research. Here we report the development of new lines of FFMM that have been bred for amenability to genetic transformation. By hybridizing a transformable maize genotype high Type-II callus parent A (Hi-II A) with line A of FFMM, we introgressed the ability to form embryogenic callus from Hi-II A into the FFMM-A genetic background. Through multiple generations of iterative self-hybridization or doubled-haploid method, we established maize lines that have a strong ability to produce embryogenic callus from immature embryos and maintain resemblance to FFMM-A in flowering time and stature. Using an Agrobacterium-mediated standard transformation method, we successfully introduced the CRISPR-Cas9 reagents into immature embryos and generated transgenic and mutant lines displaying the expected mutant phenotypes and genotypes. The transformation frequencies of the tested genotypes, defined as the numbers of transgenic event producing T1 seeds per 100 infected embryos, ranged from 0 to 17.1%. Approximately 80% of transgenic plants analyzed in this study showed various mutation patterns at the target site. The transformable FFMM line, FFMM-AT, can serve as a useful genetic and genomic resource for the maize community.
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Affiliation(s)
- Morgan E. McCaw
- Department of Agronomy, Iowa State University, Ames, IA, United States
- Crop Bioengineering Center, Iowa State University, Ames, IA, United States
| | - Keunsub Lee
- Department of Agronomy, Iowa State University, Ames, IA, United States
- Crop Bioengineering Center, Iowa State University, Ames, IA, United States
| | - Minjeong Kang
- Department of Agronomy, Iowa State University, Ames, IA, United States
- Crop Bioengineering Center, Iowa State University, Ames, IA, United States
- Interdepartmental Plant Biology Major, Iowa State University, Ames, IA, United States
| | - Jacob D. Zobrist
- Department of Agronomy, Iowa State University, Ames, IA, United States
- Crop Bioengineering Center, Iowa State University, Ames, IA, United States
- Interdepartmental Genetics and Genomics Major, Iowa State University, Ames, IA, United States
| | - Mercy K. Azanu
- Department of Agronomy, Iowa State University, Ames, IA, United States
- Crop Bioengineering Center, Iowa State University, Ames, IA, United States
- Interdepartmental Plant Biology Major, Iowa State University, Ames, IA, United States
| | - James A. Birchler
- Crop Bioengineering Center, Iowa State University, Ames, IA, United States
- Division of Biological Sciences, University of Missouri, Columbia, MO, United States
| | - Kan Wang
- Department of Agronomy, Iowa State University, Ames, IA, United States
- Crop Bioengineering Center, Iowa State University, Ames, IA, United States
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12
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Particle bombardment technology and its applications in plants. Mol Biol Rep 2020; 47:9831-9847. [PMID: 33222118 DOI: 10.1007/s11033-020-06001-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 11/11/2020] [Indexed: 12/15/2022]
Abstract
Particle bombardment, or biolistics, has emerged as an excellent alternative approach for plant genetic transformation which circumvents the limitations of Agrobacterium-mediated genetic transformation. The method has no biological constraints and can transform a wide range of plant species. Besides, it has been the most efficient way to achieve organelle transformation (for both chloroplasts and mitochondria) so far. Along with the recent advances in genome editing technologies, conventional gene delivery tools are now being repurposed to deliver targeted gene editing reagents into the plants. One of the key advantages is that the particle bombardment allows DNA-free gene editing of the genome. It enables the direct delivery of proteins, RNAs, and RNPs into plants. Owing to the versatility and wide-range applicability of the particle bombardment, it will likely remain one of the major genetic transformation methods in the future. This article provides an overview of the current status of particle bombardment technology and its applications in the field of plant research and biotechnology.
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13
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Ishida Y, Hiei Y, Komari T. Tissue culture protocols for gene transfer and editing in maize ( Zea mays L.). PLANT BIOTECHNOLOGY (TOKYO, JAPAN) 2020; 37:121-128. [PMID: 32821218 PMCID: PMC7434677 DOI: 10.5511/plantbiotechnology.20.0113a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 01/13/2020] [Indexed: 05/28/2023]
Abstract
Efficient methods for gene transfer to maize were developed in the 1990s, first mediated by particle bombardment and then by Agrobacterium tumefaciens. Both methods can efficiently create high-quality events. Genetically modified varieties were commercialized in 1996 and are now planted in more than 90% of the US corn field. Tissue culture protocols for both methods have been well developed and widely employed. Thus, various factors, including handling before gene delivery, techniques to protect cells during gene delivery, and culture media, have been well optimized for various genotypes. Typical protocols for both methods are herein presented to show major outputs from the studies conducted since the early 1990s. As the bombardment protocols tended to be optimized specifically for limited genotypes, the one for B104, a new public inbred with favorable agronomic characteristics, is shown. The Agrobacterium protocol is suitable for various inbred lines, including B104. These protocols are also useful starting points in the optimization of tissue culture for gene editing. The rate-limiting step in both transformation and gene editing is in tissue culture and plant regeneration from modified cells in elite germplasm. Despite the prolonged efforts, large varietal differences in tissue culture responses remain a serious issue in maize. Recently, protocols using morphogenic regulator genes, such as Bbm and Wus2, have been developed that show a strong potential of efficiently transforming recalcitrant varieties.
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Affiliation(s)
- Yuji Ishida
- Plant Innovation Center, Japan Tobacco, Inc., 700 Higashibara, Iwata, Shizuoka 438-0802, Japan
| | - Yukoh Hiei
- Plant Innovation Center, Japan Tobacco, Inc., 700 Higashibara, Iwata, Shizuoka 438-0802, Japan
| | - Toshihiko Komari
- Plant Innovation Center, Japan Tobacco, Inc., 700 Higashibara, Iwata, Shizuoka 438-0802, Japan
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Cunningham FJ, Demirer GS, Goh NS, Zhang H, Landry MP. Nanobiolistics: An Emerging Genetic Transformation Approach. Methods Mol Biol 2020; 2124:141-159. [PMID: 32277452 PMCID: PMC10461872 DOI: 10.1007/978-1-0716-0356-7_7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Biolistic delivery of biomolecular cargoes to plants with micron-scale projectiles is a well-established technique in plant biotechnology. However, the relatively large micron-scale biolistic projectiles can result in tissue damage, low regeneration efficiency, and create difficulties for the biolistic transformation of isomorphic small cells or subcellular target organelles (i.e., mitochondria and plastids). As an alternative to micron-sized carriers, nanomaterials provide a promising approach for biomolecule delivery to plants. While most studies exploring nanoscale biolistic carriers have been carried out in animal cells and tissues, which lack a cell wall, we can nonetheless extrapolate their utility for nanobiolistic delivery of biomolecules in plant targets. Specifically, nanobiolistics has shown promising results for use in animal systems, in which nanoscale projectiles yield lower levels of cell and tissue damage while maintaining similar transformation efficiencies as their micron-scale counterparts. In this chapter, we specifically discuss biolistic delivery of nanoparticles for plant genetic transformation purposes and identify the figures of merit requiring optimization for broad-scale implementation of nanobiolistics in plant genetic transformations.
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Affiliation(s)
- Francis J Cunningham
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, USA
| | - Gozde S Demirer
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, USA
| | - Natalie S Goh
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, USA
| | - Huan Zhang
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, USA
| | - Markita P Landry
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, USA.
- California Institute for Quantitative Biosciences, QB3, University of California, Berkeley, CA, USA.
- Chan-Zuckerberg Biohub, San Francisco, CA, USA.
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