Plants release up to 50 per cent of photosynthetically-derived carbon from their roots as a complex mixture of organic compounds known as root exudates. These compounds fuel diverse root-associated microbial communities that consist of plant growth-promoting species as well as those that cause disease or compete with plants for resources. By changing the mixture of exudates released from their roots, plants are thought to exert some level of control over the selection of their microbial symbionts.

Current evidence indicates that most root-associated microorganisms are chemotactic, in that they have the ability to sense substrates released by roots and direct movement towards them. This ability enables them to respond rapidly to resources as they become available and out-compete neighbouring populations. At present there's no information regarding the selectivity of different exudate components for specific groups of chemotactic organisms.

For this project, we'll use a novel chemotaxis assay in combination with high-throughput sequencing and flow cytometry to identify and enumerate microorganisms that respond to different root exudate components. This information will identify exudates that are strongly associated with the recruitment of beneficial and/or deleterious organisms and should facilitate the development of crops that select for beneficial root-microbial communities.

Location: St Lucia

Expected outcomes: experience in and knowledge of modern methods in plant and microbial sciences that may be applied to broader ecological fields as well as industry

Supervisors: Dr Paul Dennis

Before you apply: contact the primary supervisor for more details

Project members

Dr Paul Dennis

Lecturer in Soil Science
School of Agriculture and Food Sciences