Engineering Synthetic Apomixis in Hybrid Rice

Area of Science:

• Plant genetics and breeding
• Agricultural biotechnology
• Reproductive biology

Background:

• Apomixis, clonal reproduction via seeds, offers potential for stable F1 hybrids in crops.
• Previous attempts to transfer apomixis from wild species to crops have been unsuccessful.
• Engineering apomixis mimics natural gametophytic diplosporous apomixis.

Purpose of the Study:

• To develop a highly efficient method for achieving synthetic apomixis in crop plants.
• To enable the production of clonal F1 hybrid seeds, revolutionizing crop propagation.
• To describe methods for generating and verifying synthetic apomictic events.

Main Methods:

• Designed an 'all-in-one' T-DNA construct for rice transformation.
• Utilized CRISPR-Cas9 to create a Mitosis instead of Meiosis (MiMe) triple mutant, eliminating meiosis.
• Introduced a BABY BOOM1 (BBM1) transcription factor under an egg cell-specific promoter for parthenogenesis.

Main Results:

• Achieved high-frequency (95-100%) synthetic apomixis in rice using the T-DNA construct.
• Successfully generated synthetic apomictic events in three additional F1 hybrid rice lines.
• Developed methods for analyzing MiMe mutations and confirming apomictic progeny through BBM1 expression.

Conclusions:

• The 'all-in-one' T-DNA method is highly efficient for inducing synthetic apomixis in rice.
• This engineered apomixis enables the production of true-breeding F1 hybrid seeds.
• The technology holds significant promise for revolutionizing agriculture and crop breeding.