High rates of homologous recombination (HR) in comparison to other plants make the moss Physcomitrella patens an attractive model organism for genetic studies as well as biotechnological applications. We describe a simple protocol for the efficient biolistic transformation of protonemal tissue with minimum tissue handling steps.
The transformation efficiency depends on the biolistic conditions. The bombardment of tissue with 1 μm gold particles yielded between 20 and 40 stable transformants per 1 μg of DNA.
Transformation with circular plasmids generates higher frequencies of random transgene integration, whereas linear plasmids are more efficient in generating gene-targeted insertions.