An Effective Somatic-Cell Regeneration and Genetic Transformation Method Mediated by Agrobacterium tumefaciens for Portulaca oleracea L.

Abstract

Purslane (Portulaca oleracea L.) is highly valued for its nutritional, medicinal, and ecological significance. Genetic transformation in plants provides a powerful tool for gene manipulation, allowing for the investigation of important phenotypes and agronomic traits at the genetic level. To develop an effective genetic transformation method for purslane, various organ tissues were used as explants for callus induction and shoot regeneration. Leaf tissue exhibited the highest dedifferentiation and regeneration ability, making it the optimal explant for tissue culture. By culturing on Murashige and Skoog (MS) medium supplemented with varying concentrations of 6-benzyleaminopurine (6-BA) and 1-naphthaleneacetic acid (NAA), somatic cells from leaf explants could be developed into calli, shoots, and roots. The shoot induction results of 27 different purslane accessions elucidated the impact of genotype on somatic-cell regeneration capacity and further confirmed the effectiveness of the culture medium in promoting shoot regeneration. On this basis, a total of 17 transgenic plants were obtained utilizing the genetic transformation method mediated by Agrobacterium. The assessment of GUS staining, hygromycin selection, and polymerase chain reaction (PCR) amplification of the transgenic plants as well as their progeny lines indicated that the method established could effectively introduce foreign DNA into the purslane nucleus genome, and that integration was found to be stably inherited by offspring plants. Overall, the present study demonstrates the feasibility and reliability of the Agrobacterium-mediated genetic transformation method for introducing and integrating foreign DNA into the purslane genome, paving the way for further research and applications in purslane genetic modification.