Research 

Background

Microbiosis – here defined as ‘colonized or infected by microorganisms’ - is the dominant state of most living organisms, including plants. In plants, microorganisms function together with host genetics and the abiotic environment to help regulate processes like growth, flowering, stress resistance and the outcomes of disease and herbivory. Therefore, from both a basic research and applied agriculture point of view, we need to understand how plant-associated microorganisms colonize hosts and their implications. 

Interestingly, in nature things do not always work out the way one would expect. For example, suppression of plant immunity enables growth of poorly adapted microbes, but pathogens that suppress immunity are not usually overrun by competitors. Indeed, leaf microbial diversity seems to be rather correlated with healthy plants. On the other hand, bacteria that can cause disease are frequently found in disease-free leaves. Additionally, the strain-level genetic diversity of leaf microbes is substantial, suggesting that they are subject to diverse selective pressures. All of this points to the fact that plants are living ecosystems simultaneously colonized by diverse prokaryotes and eukaryotes who must interact with one another. Although theory and bottom-up microbial ecology approaches can tell us a lot about when and why microbes interact, our understanding of plants as an ecosystem is poor. 

Overview

In the Plant Microbiosis Lab, we study diversity and ecology of microbes in diverse plants (especially their leaves) to understand what it means for plant and ecosystem health. In particular we are working on:

• How do microorganisms in natural pools (soils, air, etc) transition to reach and colonize plant leaves?

• How  do microbe-microbe interactions in leaves shape bacterial diversity in plants?

• How do plant traits, especially the chemical environment, influence the arisal of inter-microbial interactions?

• How does environment (e.g., temperature) shape host-microbe-microbe interactions?

• What do interactions between microorganisms mean for balance in the plant microverse and host health?

Our techniques are diverse, we collaborate a lot, and most projects are built on the idea that immense diversity and ecological stories are literally right in our backyards waiting to be discovered. We believe that by understanding these stories occuring in nature, we can learn how structures and functions  of plant-associated microbiota are shaped, leading to better approaches to utilize microbiota to promote plant welfare.