High-efficiency <i>Agrobacterium</i>-mediated transformation of chrysanthemum via vacuum infiltration of internode

Abstract

Leaf disc transformation is one of the traditional methods that are now widely used in chrysanthemum with highly economical and ornamental value in world flower production, but it depends on plant genotypes and is time consuming and complicated. In addition, the transformation success rate of this method is low, generally ranging from 0.1% to 6.25%. Therefore, a highly efficient transformation system is needed. In this study, we are the first to establish a high-efficient chrysanthemum <i>Agrobacterium</i>-mediated transformation system via vacuum infiltration. Chrysanthemum stem internode explants were used as research material and <i>CmLEC1</i> was used as a reporter gene. After approximately 3 months of culture and selection, the positive transgenic plants were obtained. Additionally, the positive probability was about 42%. The transformation efficiency was up to 37.7%, and if the escapes were removed, it was 16%. Furthermore, stable expression of <i>CmLEC1</i> in transgenic 'Yuhualuoying' was confirmed by qRT-PCR analysis. These results suggest that this genetic transformation system via vacuum infiltration of chrysanthemum stem internode is highly efficient and convenient, and much better than traditional leaf disc transformation, and it will play an important role in chrysanthemum transformation and functional genetics research.