AUTHOR=Guan Shixin , Kang Xuening , Ge Jiayuan , Fei Riwen , Duan Siyang , Sun Xiaomei 

TITLE=An efficient Agrobacterium-mediated transient transformation system and its application in gene function elucidation in Paeonia lactiflora Pall

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.999433

DOI=10.3389/fpls.2022.999433

ISSN=1664-462X

ABSTRACT=<p><italic>Paeonia lactiflora</italic> Pall. is known as the king of herbaceous flowers with high ornamental and precious medicinal value. However, the lack of a stable genetic transformation system has greatly affected the research of gene function in <italic>P. lactiflora.</italic> The <italic>Agrobacterium</italic>-mediated transient gene expression is a powerful tool for the characterization of gene function in plants. In this study, the seedlings of <italic>P. lactiflora</italic> were used as the transformation receptor materials, and the efficient transient transformation system with a GUS reporter gene was successfully established by <italic>Agrobacterium</italic> harboring pCAMBIA1301. To optimize the system, we investigated the effects of germination time, <italic>Agrobacterium</italic> cell density, infection time, acetosyringone (AS) concentration, co-culture time, negative pressure intensity, Tween-20 concentration and different receptor materials on the transient transformation efficiency of <italic>P. lactiflora.</italic> The results showed that the highest transient transformation efficiency (93.3%) could be obtained when seedlings in 2-3 cm bud length were subjected to 12 h infection of resuspension solution comprising 1.2 OD<sub>600</sub><italic>Agrobacterium</italic>, 200 μM AS and 0.01% Tween-20 under 10 of negative pressure intensity followed by 3 days of co-culture in darkness condition. This method is more suitable for the study of gene function in <italic>P. lactiflora.</italic> Subsequently, stress resistance genes <italic>PlGPAT</italic>, <italic>PlDHN2</italic> and <italic>PlHD-Zip</italic> were used to verify the effectiveness of this transformation system. These results can provide critical information for identification of key genes in non-model plants, such as <italic>P. lactiflora</italic>, and promote the development of molecular biology research for <italic>P. lactiflora</italic>.</p>