New Delivery Tool Framework Replaces Time Consuming Cell Regeneration Bottlenecks

Clustered regularly interspaced short palindromic repeat (CRISPR)-Cas technologies have transformed plant biotechnology, but getting editing machinery into plant cells remains a major bottleneck. Stable transformation and tissue culture regeneration are effective but time-consuming, technically demanding, and not available for many crop species or cultivars.

Virus-induced gene editing (VIGE) offers a faster alternative by using plant viruses' natural ability to move through tissues. However, each viral vector has its own host range, and current options remain limited. Based on these challenges, there is a need to conduct in-depth research on broader, more versatile viral delivery systems for plant genome editing.

The study, conducted by researchers at the Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas–Universitat Politècnica de València, was published (DOI: 10.1093/hr/uhag017) on January 20, 2026, in Horticulture Research. It developed potyvirus-derived vectors for delivering CRISPR RNA (crRNA) guides in Lachnospiraceae bacterium ND2006 Cas12a (LbCas12a)-expressing plants, expanding VIGE from tobacco rattle virus (TRV) to tobacco etch virus (TEV), turnip mosaic virus (TuMV), and lettuce mosaic virus (LMV).

The researchers first built a visual editing system in Nicotiana benthamiana by targeting the magnesium chelatase subunit I gene, CHLI, whose disruption produces a visible pale or white leaf phenotype. Using tobacco rattle virus, they compared different crRNA sequences and architectures, showing that guide choice strongly affected editing performance and that one design incorporating a Flowering locus T RNA mobility fragment improved heritable editing. The team then engineered a tobacco etch virus vector to deliver crRNA guides systemically.

Because wild-type tobacco etch virus caused severe symptoms in N. benthamiana, they tested attenuated viral variants and identified versions that allowed plant survival, flowering, regeneration of edited plants, and rare recovery of edited non-infected progeny. The strategy was then transferred to cultivated tobacco and tomato, where tobacco rattle virus and tobacco etch virus vectors produced substantial editing. Finally, the same design was applied to turnip mosaic virus and lettuce mosaic virus, showing that multiple potyvirus vectors can support Cas12a-based VIGE.

The authors said the study shows how a large and diverse group of plant RNA viruses can be repurposed into practical delivery tools for genome editing. They emphasized that potyviruses are especially attractive because, together, they infect many plant hosts of agricultural importance. The work does not yet remove all technical barriers: the plants still expressed LbCas12a, and heritable editing through seed was rare. Even so, they said the results provide a clear route for expanding VIGE beyond a small set of established viral vectors and toward crop systems where conventional editing remains difficult.

This work could help accelerate functional genomics and crop improvement by giving researchers more options for matching viral vectors to specific plant hosts. In the longer term, potyvirus-based systems may support faster testing of gene function, recovery of edited plants from infected tissues, and development of editing strategies for crops that are poorly suited to stable transformation. The study also points to future improvements, including stronger heritable editing, antiviral regeneration strategies, and compact Cas enzymes that may eventually allow fully virus-delivered, transgene-free, tissue culture-free, and DNA-free plant genome editing. For agriculture, that could mean a more accessible path to precise crop improvement.