A Fast, Efficient, and Tissue-Culture-Independent Genetic Transformation Method for Panax notoginseng and Lilium regale

The <i>Agrobacterium</i>-based transgenic technique is commonly used for gene function validation and molecular breeding. However, it is not suitable for plants with a low regeneration capacity or a low transformation rate, such as <i>Panax notoginseng</i> (Burk) F.H. Chen and <i>Lilium regale</i> Wilson. In this study, a novel <i>Agrobacterium</i> transformation method based on injection in the meristems was developed using <i>P. notoginseng</i> and <i>L. regale</i> as experimental models. PCR analysis confirmed the successful integration of the reporter gene <i>DsRed2</i> (<i>Discosoma striata red fluorescence protein 2</i>) into the genome of two experimental models. QRT-PCR and Western blot analysis demonstrated the transcriptional and translational expression of DsRed2. Additionally, laser confocal microscopy confirmed the significant accumulation of the red fluorescent protein in the leaves, stems, and roots of transformed <i>P. notoginseng</i> and <i>L. regale</i>. Most importantly, in the second year after injection, the specific bright orange fluorescence from DsRed2 expression was observed in the transgenic <i>P. notoginseng</i> and <i>L. regale</i> plants. This study establishes a fast, efficient, and tissue-culture-independent transgenic technique suitable for plants with a low regeneration capacity or a low transformation rate. This technique may improve the functional genomics of important medicinal and ornamental plants such as <i>P. notoginseng</i> and <i>L. regale</i>, as well as their molecular breeding.