Replicating Arabidopsis Model Leaf Surfaces for Phyllosphere Microbiology

Artificial surfaces are commonly used in place of leaves in phyllosphere microbiology to study microbial behaviour on plant leaf surfaces. Studies looking into individual environmental factors influencing microorganisms are routinely carried out using artificial surfaces. Commonly used artificial surfaces include nutrient agar, isolated leaf cuticles, and reconstituted leaf waxes. However, interest is growing in using microstructured surfaces mimicking the complex topography of leaf surfaces for phyllosphere microbiology. As such replica leaf surfaces, produced by microfabrication, are appearing in literature. Replica leaf surfaces have been produced in agar, epoxy, polystyrene, and polydimethylsiloxane (PDMS). However, these protocols are not suitable for replicating fragile leaves such as of the model plant Arabidopsis thaliana. This is of importance as A. thaliana is a model system for molecular plant genetics, molecular plant biology, and microbial ecology. Here we present a versatile replication protocol for replicating fragile leaf surfaces into PDMS. We display the capacity of our replication process using optical microscopy, atomic force microscopy (AFM), and contact angle measurements to compare living and PDMS replica A. thaliana leaf surfaces. To highlight the use of our replica leaf surfaces for phyllosphere microbiology, we visualised bacteria on the replica leaf surfaces in comparison to living leaf surfaces.