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Crop improvement relies heavily on genetic variation that arises spontaneously through mutation. Modern breeding methods are very adept at combining this genetic variation in ways that achieve remarkable improvements in plant performance. Novel traits have also been created through mutation breeding and transgenesis. The advent of gene editing, however, marks a turning point: With gene editing, synthetic variation will increasingly supplement and, in some cases, supplant the genetic variation that occurs naturally. We are still in the very early stages of realizing the opportunity provided by plant gene editing. At present, typically only one or a few genes are targeted for mutation at a time, and most mutations result in loss of gene function. New technological developments, however, promise to make it possible to perform gene editing at scale. RNA virus vectors, for example, can deliver gene-editing reagents to the germ line through infection and create hundreds to thousands of diverse mutations in the progeny of infected plants. With developmental regulators, edited somatic cells can be induced to form meristems that yield seed-producing shoots, thereby increasing throughput and shrinking timescales for creating edited plants. As these approaches are refined and others developed, they will allow for accelerated breeding, the domestication of orphan crops and the reengineering of metabolism in a more directed manner than has ever previously been possible.
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Generating novel plant genetic variation via genome editing to escape the breeding lottery
Abstract Plant breeding relies on the presence of genetic variation, which is generated by a random process of mutagenesis that acts on existing gene pools. This variation is then recombined into new forms at frequencies impacted by the local euchromatin and heterochromatin environment. The result is a genetic lottery where plant breeders face increasingly low odds of generating a “winning” plant genotype. Genome editing tools enable targeted manipulation of the genome, providing a means to increase genetic variation and enhancing the chances for plant breeding success. Editing can be applied in a targeted way, where known genetic variation that improves performance can be directly brought into lines of interest through either deletion or insertion. This empowers approaches that are traditionally difficult such as novel domestication and introgression of wild accessions into a germplasm pool. Furthermore, broader editing-mediated approaches such as recombination enhancement and targeted random mutagenesis bring novel ways of variation creation to the plant breeding toolbox. Continued development and application of plant genome editing tools will be needed to aid in meeting critical global crop improvement needs.
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- Award ID(s):
- 1917138
- PAR ID:
- 10353458
- Date Published:
- Journal Name:
- In Vitro Cellular & Developmental Biology - Plant
- Volume:
- 57
- Issue:
- 4
- ISSN:
- 1054-5476
- Page Range / eLocation ID:
- 627 to 644
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1007/s11627-021-10213-0
