Protein expression and gene editing in monocots using foxtail mosaic virus vectors

Area of Science:

• Plant virology
• Molecular biology
• Biotechnology

Background:

• Plant viruses are being engineered for various applications, including gene silencing, protein expression, and gene editing.
• Foxtail mosaic virus (FoMV) has potential as a vector for manipulating plant genomes.

Purpose of the Study:

• To develop and characterize FoMV-based vectors for transient gene expression and Cas9-mediated gene editing in plants.
• To demonstrate the utility of these vectors in maize, Setaria viridis, and Nicotiana benthamiana.

Main Methods:

• Modification of FoMV by duplicating the capsid protein subgenomic promoter and inserting a cloning site.
• Transient expression assays using green fluorescent protein (GFP) and bialaphos resistance (BAR) genes.
• Delivery of single guide RNAs (sgRNAs) for Cas9-mediated gene editing in target genes.
• Assessment of editing efficiency with and without synergistic viruses and silencing suppressors.

Main Results:

• Modified FoMV vectors successfully expressed GFP and BAR proteins in infected plants.
• Plants showed temporary herbicide resistance, confirming BAR expression.
• sgRNAs delivered via FoMV mediated gene editing in target genes across species.
• Editing efficiency was enhanced by synergistic viruses and viral silencing suppressors.

Conclusions:

• Engineered FoMV vectors provide a robust platform for transient gene expression and gene editing in diverse plant species.
• These vectors expand the applications of FoMV for virus-induced gene silencing (VIGS), virus-mediated overexpression (VOX), and virus-enabled gene editing (VEdGE).
• The developed FoMV vectors are valuable tools for plant biotechnology, particularly in monocots.