What is it about?

Diverse communities of microbes live on plant roots. Plants release a mixture of different chemicals from their roots and these exudates serve as food for the microbes. The exudates also contain special metabolites that often have antimicrobial effects. Here we tested a collection of maize root bacteria for their tolerance against such bioactive metabolites. We found that the bacteria responded very differently to these substances. Generally, tolerant bacteria were also more abundant on the roots. Our work shows how plant metabolites can control the growth of root bacteria and shows how plants steer their root microbial communities.

Featured Image

Why is it important?

Root microbial communities are important for plant growth and health. The mechanisms how plants structure their root microbial communities are only poorly understood. Here we show mechanistically how benzoxazinoids act as selective antibiotics to structure the maize root microbiome. This is particularly important to engineer crops with a beneficial microbiome.


This is the first published article of my PhD. It was my first task to isolate and characterize a broad collection of maize root bacteria. I really enjoyed working with such a diverse collection of maize root bacteria. By the end of the project, I was able to name each bacterial isolate solely by visual inspection. Fortunately, I had the assistance of a robot that made my work 25 times faster. The novel combination of a culture collection, phenotyping tests and microbiome analysis gives new mechanistic insights into the structure of the plant root microbiome. I hope this article also gives an insight into the colourful and diverse world that hides beneath corn fields.

Lisa Thönen
Universitat Basel

Read the Original

This page is a summary of: Bacterial tolerance to host-exuded specialized metabolites structures the maize root microbiome, Proceedings of the National Academy of Sciences, October 2023, Proceedings of the National Academy of Sciences,
DOI: 10.1073/pnas.2310134120.
You can read the full text:



The following have contributed to this page