Genome Editing Enables Next-Generation Hybrid Seed Production Technology

Area of Science:

• Agricultural biotechnology
• Plant genetics
• Gene editing

Background:

• Next-generation hybrid seed production relies on genic male sterile (GMS) lines and maintainers.
• Current methods are laborious and complex, involving multiple steps.
• A simplified, efficient strategy is needed to improve hybrid seed production.

Purpose of the Study:

• To design a simple, single-transformation strategy for hybrid seed production using CRISPR/Cas9 technology.
• To create a Manipulated GMS Maintainer (MGM) system for maize.
• To enable efficient sorting of hybrid seeds.

Main Methods:

• Utilized CRISPR/Cas9 to create an MGM system in maize.
• Nullified the maize male fertility gene ZmMS26 via exon removal.
• Co-transformed a vector restoring ZmMS26 function, including a male gametophyte inactivation gene (ZmAA1) and an endosperm fluorescent marker (DsRED).

Main Results:

• Generated single-copy hemizygous MGM lines with a mutated MS26 gene, resulting in complete male sterility.
• MGM lines exhibited normal vegetative growth and grain yield.
• The system prevented genetic transmission via male gametophytes, enabling DsRED-based sorting of maintainer seeds.

Conclusions:

• The developed MGM system offers a simplified and efficient approach to hybrid seed production.
• This strategy effectively sorts maintainer seeds using a fluorescent marker.
• The technology is adaptable for various GMS genes and hybrid crops beyond maize.