Comparison of Replica Leaf Surface Materials for Phyllosphere Microbiology

Artificial surfaces are routinely used instead of leaves to enable a reductionist approach in phyllosphere microbiology, the study of microorganisms residing on plant leaf surfaces. For instance, flat surfaces such as nutrient agar, enable the influence of nutrient supply on microorganisms to be investigated. In contrast microstructured surfaces, such as isolated leaf cuticles or reconstituted leaf waxes enable the influence of physicochemical properties to be investigated. However, interest in replica leaf surfaces as an artificial surface is growing. As replica surfaces offer an improved representation of the complex topography of leaf surfaces. The use of replica leaf surfaces has to date primarily been focused on replicating the superhydrophobic surfaces of leaves. Whereas in this paper, we investigate potential replica surface materials for phyllosphere microbiology studies. Using a test pattern, we investigated the resolution, the degradation characteristics in environmental conditions, surface energy, and bacterial survival characteristics for each potential replica material. Our results indicate that PDMS is the most suitable material for producing replica leaf surfaces. Due to the high resolution achieved through replica molding, extended stability, hydrophobic properties, and bacterial survival characteristics comparable to isolated leaf cuticles. Our experiments highlight the importance of considering the inherent material properties, when selecting a replica leaf surface for phyllosphere microbiology studies. A replica leaf produced in PDMS offers a control surface that can be used for investigating microbe-microbe and microbe-plant interactions in the phyllosphere. Thus, in turn enabling mitigation strategies against pathogens to either the plant host or humans to be developed.