Microbial Chemotaxis in the Phyllosphere

PRINCIPAL INVESTIGATOR: GERTH

MARSDEN FUND (2019-2022)

Plant leaves are a major habitat for bacteria in the phyllosphere (i.e. the above ground parts of plants). However, the surface of a leaf is a challenging place to live. In contrast, the interior of a plant contains comparatively abundant nutrients and mild environmental conditions that allow microbial pathogens to thrive and cause disease. Bacterial pathogens of plants are unable to directly penetrate the surface on their own; they must gain entry through natural openings such as stomata or wounds. The molecular basis of how bacteria navigate between these vastly different habitats remains poorly understood.

Motile bacteria are attracted by certain chemicals and repelled by others, a behaviour termed chemotaxis, which enables them to navigate towards favourable conditions. Our research is exploring the ‘what, how and why’ of bacterial chemotaxis in the phyllosphere. Longer-term, these insights may lead to novel plant disease management strategies