Efficient genetic transformation and gene editing in Erigeron breviscapus using developmental regulators

The demand for Erigeron breviscapus, a medicinal Compositae plant with cardiovascular therapeutic properties, has been increasing by 15% annually, exceeding production capacity and necessitating improvements in yield and bioactive compound content. Genetic transformation remains essential for functional genomics, yet current Agrobacterium and biolistic methods are inefficient and expensive. In this study, we cloned the full-length sequences of the BABY BOOM, WUSCHEL and GROWTH-REGULATING FACTOR (GRF) genes of E. breviscapus and then transformed them into E. breviscapus explants. The transformation efficiency for the GRF gene reached 45%, and all the transgenic E. breviscapus plants were fertile without obvious developmental defects. Furthermore, we inserted EbGRF4 and Cas9-EbPDS-sgRNA into the same vector for Agrobacterium-mediated transformation to effectively knock out the PDS gene, resulting in albino seedlings, with a gene editing efficiency of 33.3%. These findings provide a solid foundation for functional genomic research and the genetic improvement of E. breviscapus, as well as an important reference for establishing high-efficiency genetic transformation systems for other medicinal plants.