Electroporation-Mediated Gene Delivery in Pyropia yezoensis (Rhodophyta) Without Cell Wall Removal

This study aimed to assess the potential of a gene delivery technique in the red macroalga Pyropia yezoensis (Rhodophyta) using electroporation without removing the cell wall. An antibiotic resistance gene was introduced into P. yezoensis tissues containing cells with intact cell walls through electroporation, followed by selection with the corresponding antibiotic. No germlings survived in the non-electroporated control tissue fragments under antibiotic selection. In contrast, some germlings were observed to survive in the electroporated group. Furthermore, the presence of antibiotic resistance genes was confirmed in the genomic DNA of several antibiotic-resistant germlings. Although reporter genes such as β-glucuronidase (GUS) and green fluorescent protein (GFP) were also introduced as supplementary markers, their expression was not detectable under the tested conditions. These findings provide evidence supporting the successful introduction of antibiotic resistance genes into P. yezoensis cells via electroporation. This study offers a preliminary assessment of a gene delivery strategy in P. yezoensis that bypasses cell wall removal, presenting a straightforward method for introducing foreign genes into Pyropia. To the best of our knowledge, this is the first report to demonstrate successful gene transfer via electroporation in a macroalga without cell wall removal. These results provide valuable insights for the development of genetic transformation systems in red macroalgae.