Novel and efficient transformation of wild passion fruit (Passiflora cincinnata Mast.) using sonication-assisted Agrobacterium-mediated transformation

Passiflora cincinnata stands out among Passifloraceae because of its medicinal properties and its resistance to pathogens, which promotes its use as a rootstock for other Passiflora species. A valuable strategy for obtaining disease-resistant passion fruit plants is represented by genetic transformation; however, this requires efficient regeneration. Here, we aimed to establish an efficient protocol for generating transgenic passion fruit plants using sonication-assisted Agrobacterium-mediated transformation of somatic embryos. The latter were obtained from anthers, sonicated, and exposed to an Agrobacterium suspension for 15 or 30 s. As a comparison, non-sonicated embryos were also exposed to the same bacterial treatment, whereas non-infected embryos were used as controls. Plant identity was confirmed by PCR, qPCR, and histochemical assay. Transgenic plants were obtained at higher rates in the treatments applying sonication. Overall, 171 plantlets were regenerated, 38 of which showed stable uidA reporter gene expression. Of these 38 transgenic plants, 22 (57.89%) and 13 (34.21%) were obtained by sonication-assisted Agrobacterium-mediated transformation for 30 s and 15 s, respectively, whereas the remaining 3 (7.89%) were exposed for 30 s but without prior sonication. Our results indicate that sonication-assisted Agrobacterium-mediated transformation for 30 s enhanced transformation efficiency in P. cincinnata. We believe that this system will allow for more efficient production of transgenic passion fruit plants.

Automated summary

Sonication-assisted Agrobacterium-mediated transformation can enhance transformation efficiency in Passiflora cincinnata, which is crucial for obtaining disease-resistant passion fruit plants.