Improved G-AgarTrap: A highly efficient transformation method for intact gemmalings of the liverwortMarchantia polymorpha
AbstractLiverworts are key species for studies of plant evolution, occupying a basal position among the land plants.Marchantia polymorphahas emerged as a highly studied model liverwort, and many relevant techniques, including genetic transformation, have been established for this species.Agrobacterium-mediated transformation is widely used in many plant species because of its low cost. Recently, we developed a simplifiedAgrobacterium-mediated method for transformingM. polymorpha, known as AgarTrap (agar-utilized transformation with pouring solutions). The AgarTrap procedure, which involves culturing the liverwort tissue in various solutions on a single solid medium, yields up to a hundred independent transformants. AgarTrap is a simple procedure, requiring minimal expertise, cost, and time.Here, we investigated four factors that influence AgarTrap transformation efficiency: (1) humidity, (2) surfactant in the transformation buffer, (3)Agrobacteriumstrain, and (4) light/dark condition. We adapted the AgarTrap protocol for transforming intact gemmalings, achieving an exceptionally high transformation efficiency of 97%. The improved AgarTrap method will enhance the molecular biological study ofM. polymorpha. The present study also provides new possibilities for improving transformation techniques for a variety of plant species.