Efficient Agrobacterium rhizogenes-mediated transformation system for fleshy roots of Paeonia ‘Coral Sunset’ without tissue culture

Herbaceous peony ( Paeonia sect. Paeonia ) is a highly esteemed medicinal and aromatic plant with significant economic value. However, the absence of a stable genetic transformation system has severely impeded progress in understanding its molecular genetic mechanisms and functional genomics, thereby limiting the enhancement of its industrial value. Therefore, this study developed a simple, rapid, efficient, and tissue culture-independent genetic transformation method using Agrobacterium rhizogenes ( A. rhizogenes ). The fleshy roots of Paeonia ‘Coral Sunset’ were infected with A. rhizogenes , without tissue culture or aseptic conditions, and positive roots were induced to obtain composite transgenic plants. Using this method, this study successfully induced transgenic positive roots and obtained composite transgenic P. ‘Coral Sunset’ plants. The positive transformation efficiency reached 86.67 ± 9.09 % ( P < 0.05). This method provided technical support for the study of genetic functional genomics and breeding resources of herbaceous peony, and laid the foundation for establishing a stable and efficient genetic transformation system for herbaceous peony. • Established a stable transformation system in Paeonia ‘Coral Sunset’ for the first time. • The improved Agrobacterium rhizogenes -mediated (ARM) requires no tissue culture. • The improved ARM enables efficient and stable gene transformation.