Viral Delivery Enables Transgene-Free Genome Editing in Arabidopsis

Researchers have developed a novel method for germline genome editing in *Arabidopsis thaliana* using a viral delivery system and an RNA-guided genome editor. This approach avoids the use of transgenic elements, addressing concerns about genetically modified organisms (GMOs). The study, published in Nature Plants in 2025, was led by Weiss, Kamalu, Shi, and colleagues. The researchers engineered a viral vector platform to transport CRISPR-Cas components directly into the germline cells of *Arabidopsis*. This system transiently introduces editing machinery, enabling precise gene modifications without stable genetic footprints. Plant viruses are used as vectors for delivering the Cas9 protein paired with guide RNAs. The viral genome was stripped of replication capabilities to minimize off-target effects. This allows controlled, transient expression of editing components. The researchers optimized the viral vector architecture to enhance infectivity and editing efficiency. This ensures that the genome edits are heritable, with modifications in germline cells propagating to progeny. Detailed molecular analyses demonstrated high precision of the editing events, with minimal off-target activity. The study also showcased the versatility of this viral delivery platform by targeting multiple genes simultaneously. This advancement's compatibility with existing regulatory frameworks is noteworthy, potentially circumventing stringent GMO regulations. The researchers also addressed biosafety concerns related to the use of viral vectors in plants. This research shifts the paradigm from permanent transgene integration towards transient, precise, and heritable genome modifications. The scalable and non-transgenic nature of this viral delivery system could accelerate the domestication and genetic enhancement of orphan crops and underutilized species.