Viral-based transient expression systems as catalysts for synthetic biology in plants

Plant synthetic biology offers transformative potential for sustainable biotechnology, precision agriculture, and recombinant protein production. However, the field faces persistent challenges, including lengthy development timelines, gene silencing, limited transformation efficiency, and regulatory hurdles surrounding stable genetic modifications. To overcome these bottlenecks, virus-based transient expression systems have emerged as powerful solutions, enabling rapid, high-level, and modular gene expression in plants without the need for stable integration. Agrobacterium -mediated delivery of deconstructed viral vectors has revolutionized the plant design-build-test-learn (DBTL) cycle. These platforms facilitate efficient expression of synthetic circuits, multigene metabolic pathways, and therapeutic proteins in model hosts such as Nicotiana species and edible species such as lettuce. When integrated with controlled environment agriculture (CEA) systems, transient expression offers a closed-loop, reproducible environment, supporting regulatory-grade biomanufacturing. Applications include rapid prototyping of genetic circuits, genome editing through CRISPR/Cas systems, and production of complex biologics such as monoclonal antibodies and vaccines. Case studies such as ZMapp and Medicago’s COVID-19 VLP vaccine illustrate the clinical relevance of this approach. Emerging innovations, including synthetic viral chassis, standardized part libraries, and AI-driven construct optimization, promise to further enhance transient expression as a foundational tool in plant synthetic biology. Collectively, these advancements are shaping a future in which plants can serve as programmable, scalable biofactories for health and industrial applications.