{"id":"doi:10.1002/pld3.70196","kind":"article","title":"Validation of a Modular Base Editing Strategy, Free-BE, in <i>Physcomitrium patens</i>, Maize, and Wheat","authors":["Guyon-Debast A","Javelle M","Perroud PF","Pichon JP","Paul W","Nogué F"],"author_count":6,"year":2026,"published":"2026-10-15","venue":"Plant direct","cited_by":0,"doi":"10.1002/pld3.70196","arxiv_id":null,"nct_id":null,"source_url":"https://doi.org/10.1002/pld3.70196","archive_url":"https://space-kitty.com/papers/doi:10.1002/pld3.70196","updated":null,"pmid":"42889475","pmcid":null,"openalex_id":null,"pdf_url":null,"abstract":"Base editing (BE) technologies enable precise genome modification but often generate undesired editing outcomes, including indels, bystander edits, and editing outside the optimal activity windows. Here, we report a modular BE strategy, termed Free-BE, where the cytidine deaminase and Cas9 nickase are delivered as separate components rather than as a single fusion protein. In the moss Physcomitrium patens , Free-BE showed lower editing efficiency than the conventional fused system (Fused-BE). However, it generated fewer indels, a higher proportion of single-nucleotide edits, and reduced out-of-window editing. Free-BE also altered the spectrum of base substitutions, producing a higher proportion of C-to-G and C-to-A transversions than Fused-BE in P. patens . No mutations were detected at four predicted off-target loci examined in P. patens . We further validated Free-BE in crop systems. In a transient maize protoplast reporter assay, Free-BE achieved targeted base conversions, whereas stable transformation of wheat demonstrated successful editing of endogenous loci, although with lower efficiency than Fused-BE. In wheat, Free-BE similarly reduced multicytidine editing and by-products. Together, these results establish Free-BE as a functional modular BE strategy that broadens the plant genome-editing toolbox and may be advantageous for applications requiring greater control over editing outcomes, despite lower overall editing efficiency.","abstract_license":"CC-BY (article license as recorded by Europe PMC; abstract reproduced unmodified apart from markup removal)","license":"CC-BY","is_open_access":false,"retracted":false,"peer_reviewed":null,"categories":[],"details":null,"provenance":"europepmc","attribution":"Abstract of \"Validation of a Modular Base Editing Strategy, Free-BE, in <i>Physcomitrium patens</i>, Maize, and Wheat\" by Guyon-Debast A, Javelle M, Perroud PF et al., https://doi.org/10.1002/pld3.70196, used under its Creative Commons Attribution license (CC-BY); markup removed, otherwise unmodified.","topics":[{"slug":"gene-editing-therapies","name":"CRISPR & Gene-Editing Therapies","domain_slug":"medicine"}],"cited_in_dossiers":[]}