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

Area of Science:

• Plant Genetics
• Agricultural Biotechnology
• Maize Genomics

Background:

• Maize (Zea mays) is a vital genetic model and global food crop.
• Precise genome manipulation technologies are advancing agricultural research and applications.
• Efficient genetic transformation protocols are crucial for crop gene editing but limited in public maize lines.

Purpose of the Study:

• To develop new Fast-Flowering Mini-Maize (FFMM) lines amenable to genetic transformation.
• To create an open-source maize research tool with enhanced genetic engineering capabilities.
• To facilitate basic biological research and biotechnological applications in maize.

Main Methods:

• Hybridization of a transformable maize genotype (Hi-II A) with FFMM-A.
• Iterative self-hybridization and doubled-haploid methods to establish new lines.
• Agrobacterium-mediated transformation using CRISPR-Cas9 reagents in immature embryos.

Main Results:

• Established FFMM lines (FFMM-AT) with strong embryogenic callus formation and FFMM traits.
• Successfully generated transgenic and mutant maize lines using CRISPR-Cas9.
• Achieved transformation frequencies ranging from 0 to 17.1% with approximately 80% of transgenic plants showing target site mutations.

Conclusions:

• The developed transformable FFMM line (FFMM-AT) is a valuable resource for the maize research community.
• This advancement enhances the utility of FFMM for genetic and genomic studies.
• Facilitates further research in maize genetics, breeding, and biotechnology.