The Moss Physcomitrella patens as a Model System to Study Interactions between Plants and Phytopathogenic Fungi and Oomycetes

The moss Physcomitrella patens has a great potential as a model system to perform functional studies of plant interacting with microbial pathogens. P. patens is susceptible to fungal and oomycete infection, which colonize and multiply in plant tissues generating disease symptoms. In response to infection, P. patens activates defense mechanisms similar to those induced in flowering plants, including the accumulation of reactive oxygen species, cell death with hallmarks of programmed cell death, cell wall fortification, and induction of defense-related genes like PAL, LOX, CHS, and PR-1. Functional analysis of genes with possible roles in defense can be performed due to the high rate of homologous recombination present in this plant that enables targeted gene disruption. This paper reviews the current knowledge of defense responses activated in P. patens after pathogen assault and analyzes the advantages of using this plant to gain further insight into plant defense strategies.