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Development of a Transformable Fast-Flowering Mini-Maize as a Tool for Maize Gene Editing

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 ap...

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Autores principales: McCaw, Morgan E., Lee, Keunsub, Kang, Minjeong, Zobrist, Jacob D., Azanu, Mercy K., Birchler, James A., Wang, Kan
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8525386/
https://www.ncbi.nlm.nih.gov/pubmed/34713243
http://dx.doi.org/10.3389/fgeed.2020.622227
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author McCaw, Morgan E.
Lee, Keunsub
Kang, Minjeong
Zobrist, Jacob D.
Azanu, Mercy K.
Birchler, James A.
Wang, Kan
author_facet McCaw, Morgan E.
Lee, Keunsub
Kang, Minjeong
Zobrist, Jacob D.
Azanu, Mercy K.
Birchler, James A.
Wang, Kan
author_sort McCaw, Morgan E.
collection PubMed
description 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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spelling pubmed-85253862021-10-27 Development of a Transformable Fast-Flowering Mini-Maize as a Tool for Maize Gene Editing McCaw, Morgan E. Lee, Keunsub Kang, Minjeong Zobrist, Jacob D. Azanu, Mercy K. Birchler, James A. Wang, Kan Front Genome Ed Genome Editing 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. Frontiers Media S.A. 2021-01-11 /pmc/articles/PMC8525386/ /pubmed/34713243 http://dx.doi.org/10.3389/fgeed.2020.622227 Text en Copyright © 2021 McCaw, Lee, Kang, Zobrist, Azanu, Birchler and Wang. https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Genome Editing
McCaw, Morgan E.
Lee, Keunsub
Kang, Minjeong
Zobrist, Jacob D.
Azanu, Mercy K.
Birchler, James A.
Wang, Kan
Development of a Transformable Fast-Flowering Mini-Maize as a Tool for Maize Gene Editing
title Development of a Transformable Fast-Flowering Mini-Maize as a Tool for Maize Gene Editing
title_full Development of a Transformable Fast-Flowering Mini-Maize as a Tool for Maize Gene Editing
title_fullStr Development of a Transformable Fast-Flowering Mini-Maize as a Tool for Maize Gene Editing
title_full_unstemmed Development of a Transformable Fast-Flowering Mini-Maize as a Tool for Maize Gene Editing
title_short Development of a Transformable Fast-Flowering Mini-Maize as a Tool for Maize Gene Editing
title_sort development of a transformable fast-flowering mini-maize as a tool for maize gene editing
topic Genome Editing
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8525386/
https://www.ncbi.nlm.nih.gov/pubmed/34713243
http://dx.doi.org/10.3389/fgeed.2020.622227
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