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Thanks to our reviewers who suggested experiments that we didn’t dare to do! In one of them, we demonstrated that the ability to use glutamine as an energy source is a great predictor of the altered bacterial synthetic community composition on mutant roots.

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nikogeldner.bsky.social @nikogeldner.bsky.social · 5d

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nikogeldner.bsky.social @nikogeldner.bsky.social · 5d

What is shown on the Science cover is a bacterial strain that turns on a fluorescent reporter in the presence of glutamine. This allowed us to visualize bacterial metabolic niche formation at the micrometer scale – a true metabolic microprobe!

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nikogeldner.bsky.social @nikogeldner.bsky.social · 5d

We demonstrate how the use of specific bacterial mutants, unable to either sense or metabolize glutamine can be used to conclude on the nature and site of root exudate release at unmatched resolution.

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nikogeldner.bsky.social @nikogeldner.bsky.social · 5d

This explains observed patterns of root colonization, but also defines what I call a “third path” of root exudate formation – transient vascular leakages - adding to the controlled secretory or transporter-mediated path and the uncontrolled release of cellular compounds during root cap shedding.

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nikogeldner.bsky.social @nikogeldner.bsky.social · 5d

Importantly, glutamine leakage also occurs in wild-type roots – at places where the endodermal barrier has not yet formed, or is transiently broken at the site of emerging lateral roots!

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nikogeldner.bsky.social @nikogeldner.bsky.social · 5d

Some of the main messages: We found that glutamine is the dominant molecule leaking from the vasculature, driving enhanced chemoattraction to - and enhanced proliferation on - the mutant roots. This applies to a broad range of bacterial species, beyond our model bacterium.

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nikogeldner.bsky.social @nikogeldner.bsky.social · 5d

Two talented, hard-working researchers in our labs, turned these early observations into the amazing story published today:
@hueihsuantsai.bsky.social and Yuanjie Tang - with the support of many collaborators: Christoph Keel, @tonnigrubeandersen.bsky.social
, @kathywippel.bsky.social and others.

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nikogeldner.bsky.social @nikogeldner.bsky.social · 5d

Many years ago, Feng Zhou, now at the CEMPS in Shanghai, found strikingly increased bacterial colonization of Arabidopsis roots lacking endodermal barriers. Laser ablating the endodermis also led to increased colonization, immediately suggesting a direct effect – something attractive is leaking!

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nikogeldner.bsky.social @nikogeldner.bsky.social · 5d

A long road to the Cover of Science!
www.science.org/doi/10.1126/...

Localized glutamine leakage drives the spatial structure of root microbial colonization

Plant roots release exudates to encourage microbiome assembly, which influences the function and stress resilience of plants. How specific exudates drive spatial colonization patterns remains largely ...

www.science.org

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nikogeldner.bsky.social @nikogeldner.bsky.social · 11d

😂 I guess it’s all relative - but even then: Do they?!

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