A highly efficient AgarTrap method for genetic transformation of mature thalli of the liverwort Marchantia polymorpha L.

Marchantia polymorpha L. has been established as a model liverwort species for understanding plant evolution, and several genetic transformation technologies have been developed. Recently, we described a simplified Agrobacterium-mediated genetic transformation method termed AgarTrap (Agar-utilized Transformation with Pouring Solutions) that uses sporelings (S-AgarTrap) or gemmae/gemmalings (G-AgarTrap), both of which easily produce a sufficient number of independent transformants. In this study, we report the development of a novel AgarTrap protocol using mature pieces of liverwort thalli (T-AgarTrap). Optimal transformation efficiency was approximately 70%, and 100% transformation was achieved in a few experimental cases. The efficiency of T-AgarTrap was much greater than those of S- and G-AgarTrap methods. This highly efficient T-AgarTrap protocol seems to promote molecular research with M. polymorpha.