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Zoe Nahas

@zoenahas.bsky.social

750 followers 330 following 34 posts

Postdoc in Fankhauser lab, University of Lausanne. Previously PhD in Leyser & Locke labs at Sainsbury Laboratory, Cambridge. Development, plants, shoot branching, auxin, evo/devo, systems biology, food security

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Zoe Nahas @zoenahas.bsky.social · 19d

Happy to share slightly late that the main work of my PhD is now published! How do plants regulate the number + location of growing branches 🌳🌲? We used experiments and mathematical modelling to study how local and systemic signals are integrated during shoot branching regulation. A thread:

PLOS Biology @plosbiology.org · 28d

How do #plants dynamically modulate their shoot branching for optimal returns? ‪@zoenahas.bsky.social‬ &co show that BRC1 modulates bud competitiveness by reducing #auxin efflux, integrating hormonal cues to fine-tune branching patterns @plosbiology.org @slcuplants.bsky.social 🧪 plos.io/4pnrwY2

2-node explants capture key properties of bud regulation. Top left: A stem segment with two axillary buds illustrates two regulatory hubs controlling shoot branching (i) local expression of the transcription factor BRC1, a repressor of bud activation, and (ii) systemic regulation of the auxin transport network. A canalization-based model of shoot branching postulates that bud activation requires the establishment of canalized auxin transport from the bud into the main stem, the dynamics of which is influenced by autocatalytic feedback in auxin flow between the bud and the stem, and the relative auxin source and sink strengths of the bud and stem, respectively. The relationship between BRC1- and auxin-transport-mediated regulation is not known. Bottom left: Arabidopsis bud activation occurs in at least two phases: a slow-growing lag phase, then a switch to rapid outgrowth. Typical timescale 10–12 days. Right: Diagram illustrating the four possible growth outcomes for bud activation on 2-node explants, and their representation in a Mitchison plot. Mitchison plots present the length of the top bud versus that of the bottom bud over time in each explant. Explants where at least one bud grows are termed active, otherwise, they are inactive. Within active explants, there are three possible outcomes: both buds grow, or only either the top or the bottom bud activates.

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Reposted by Zoe Nahas

Christine Faulkner @pdchristine.bsky.social · 1d

New pre-print from the team!

The manuscript is @emma-raven.bsky.social's PhD work showing that whether a leaf is a carbon sink or a carbon source influences how they execute immune responses.

Have a read!

#PlantScience
@johninnescentre.bsky.social

bioRxiv Plant Bio @biorxiv-plants.bsky.social · 1d

Primary metabolism underpins the execution of immune responses in different tissues of the same plant https://www.biorxiv.org/content/10.1101/2025.10.11.681807v1

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Reposted by Zoe Nahas

Nemo Peeters @nemopeeters.bsky.social · 7h

Check out the quality of segmentation by #OneRosette, even when leaves are dying to DC3000. Come and see nuts and bolts of this deep learning prompt-engineering by PhD candidate Felicià Maviane @lipme-toulouse.bsky.social on the 24/10/2025 13h #Margulis

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Reposted by Zoe Nahas

Christine Faulkner @pdchristine.bsky.social · 3d

We have a project available for 2026 NRP Doctoral Training Partnership entry (i.e. PhD studentship opportunity!)

How do cells communicate when it's hot?

Don't know? Me either! Come work with us @johninnescentre.bsky.social and figure it out

biodtp.norwichresearchpark.ac.uk/projects/how...

How do cells communicate when it’s hot? (FAULKNER_J26DTP) | Doctoral Training Partnership

Plant cells are connected to their neighbours via ‘tubes’ called plasmodesmata, creating an interconnected cytoplasm that joins cells within and between tissues and organs.

biodtp.norwichresearchpark.ac.uk

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Reposted by Zoe Nahas

Jim Rowe @botanicaljim.bsky.social · 5d

I was tremendously lucky to be in @xanderjones.bsky.social's lab to watch @bijuntang.bsky.social move from technician to PhD to Postdoc and produce this magnum opus. #SalicS1 is the just reward for years of brilliance and hard work.Well done Bijun, Xander, Jing, and everyone involved! #SalicylicAcid

Sainsbury Laboratory Cambridge University (SLCU) @slcuplants.bsky.social · 5d

Salicylic acid biosensor, SalicS1, tracks the plant immune hormone salicylic acid in real time - revealing propagation of hormone surge during plant pathogen advance

Latest biosensor from @xanderjones.bsky.social team
In Science doi.org/10.1126/scie...
Summary www.slcu.cam.ac.uk/news/new-bio...

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Reposted by Zoe Nahas

Sainsbury Laboratory Cambridge University (SLCU) @slcuplants.bsky.social · 5d

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Reposted by Zoe Nahas

Marc Somssich @somssich.bsky.social · 11d

People: "Things used to be better."

Scientist: "When did it start getting worse?"

People: "When I was born."

From "The illusion of moral decline" by Adam Mastroianni.
shorturl.at/FFEDV

A graph showing violin plots. On the y axis is the perceived morality of people from 0 to 8. On the x axis the time points 40 years before my birth, 20 years before my birth, at my birth, 20 years past my birth, today. The morality value is constant until birth, and then declines.

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Reposted by Zoe Nahas

Claudia Bank @cbank.bsky.social · 8d

Please spread the word! 10 days left to apply for this #sciencejobs as Assistant Professor Tenure Track in Quantitative Cell Biology 👩‍🔬
@izb-unibern.bsky.social @unibe.ch! ohws.prospective.ch/public/v1/jo...
#QueerInSTEM #DisabledInSTEM #BlackInSTEM #WomenInSTEM #CarersInSTEM #AcademicSky #HigherED

Uni Bern: Assistant Professor with tenure-track for Quantitative Cell Biology

Start date of employment: anticipated for August 2027

ohws.prospective.ch

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Reposted by Zoe Nahas

Merissa Huei-Hsuan Tsai @hueihsuantsai.bsky.social · 12d

Very excited to see our @nikogeldner.bsky.social lab x Feng Zhou lab work featured on the cover of Science!
(1/5) We reveal how root architecture and nutrient leakage shape spatial patterns of microbial colonization, moving beyond traditional models of uniform exudation.

Science Magazine @science.org · 12d

Using precise spatial and temporal analysis, researchers in Science provide insight into how bacteria around the root interact both with the plant and with each other.

Learn more in this week's issue: https://scim.ag/3WgNajk

A confocal microscopy image shows root-colonizing bacteria clustering around an emerging lateral root, where localized glutamine leakage induces spatially confined reporter activity.

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Reposted by Zoe Nahas

John Innes Centre @johninnescentre.bsky.social · 12d

VACANCY - Independent research fellowships leading to tenured positions

We’re inviting applications from outstanding researchers who either hold, or wish to apply for, Independent Research Fellowships.

APPLICATION DEADLINE: 10 November 2025

Click here to apply: jic.link/Fellows

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Reposted by Zoe Nahas

nikogeldner.bsky.social @nikogeldner.bsky.social · 12d

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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Reposted by Zoe Nahas

Xander Jones @xanderjones.bsky.social · 12d

Only a few days left to apply!

My group is looking for a postdoc to engineer and deploy new tools to precisely manipulate and decode how auxin coordinates plant morphogenesis.

@starmorph-syg.bsky.social

Research Associate - Reprogramming Development (closes 7 October 2025)

www.cam.ac.uk

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Reposted by Zoe Nahas

Hilde Schneemann @hildeschneemann.bsky.social · 17d

🚂 This petition needs your signatures! Save the wonderful nighttrain that gets you into the center of Paris/Vienna/Berlin in time for breakfast whilst you doze off or have memorable encounters and conversations with fellow travellers agir.greenvoice.fr/petitions/sa...

🚂 Sauvons les trains de nuit Paris-Berlin et Paris-Vienne

Signez la pétition maintenant !

agir.greenvoice.fr

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Reposted by Zoe Nahas

Cristina Ferrándiz @cristicris.bsky.social · Sep 11

It was already known that auxins (surprise!) had a key role controlling the end of flowering, plant menopause. Now we can tell you how and where they act in the inflorescence meristem to control the process.
@irenegonzlez.bsky.social
www.cell.com/current-biology/fulltext/S0960-9822%2825%2901002-4

Local regulation of auxin-related pathways in the shoot apical meristem plays a major role during proliferative arrest

González-Cuadra et al. show that repression of auxin-related pathways locally in the SAM is key in the control of proliferative arrest. FRUITFULL regulates these pathways to promote meristem arrest. B...

www.cell.com

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Zoe Nahas @zoenahas.bsky.social · 19d

Oh amazing @jamespblloyd.bsky.social, this makes me very happy to hear, so thank you! My PhD built very directly on previous work in the Leyser group, including Scott's :)

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Zoe Nahas @zoenahas.bsky.social · 19d

Thanks Adrien!! @halloulab.bsky.social

Zoe Nahas @zoenahas.bsky.social · 19d

Thanks Jim! Hope you're well :)

Zoe Nahas @zoenahas.bsky.social · 19d

Check out the link below for a summary of our recent paper on how plants coordinate their branching architecture, via @slcuplants.bsky.social 🌱

Sainsbury Laboratory Cambridge University (SLCU) @slcuplants.bsky.social · 26d

🌱From Bud to Branch🌱
New model reveals how local & systemic signals combine to regulate shoot branching.
"...by modulating #auxin transport, local #BRC1 expression in each bud could contribute to the systemic control of branching." @zoenahas.bsky.social
🔗 dx.plos.org/10.1371/jour...
@plosbiology.org

Axillary buds are located at the base of each leaf. Initially dormant, each can grow into a branch. To study how branching is regulated by local signalling within each bud and by systemic signalling from other buds, we used stem sections with two axillary buds and their associated leaves (left). This signalling network influences, for example, whether one bud grows and rapidly inhibits the other (middle), or whether both buds grow simultaneously (right).

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Zoe Nahas @zoenahas.bsky.social · 19d

TLDR: Combining experiments + modelling is really useful (& fun ✨) to generate and test hypotheses about multi-scale signal integration. We propose an integrated model of shoot branching regulation that accounts for the ability of buds to regulate the number + location of growing branches 16/16

Zoe Nahas @zoenahas.bsky.social · 19d

It's interesting that BRC1 is responsive to local environmental cues like light. Having local sensing relayed into a decentralised mode of regulation could enable flexible adjustment of branching to heterogenous environmental conditions while maintaining whole-plant coordination 15/n

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Zoe Nahas @zoenahas.bsky.social · 19d

The overall point? We propose that BRC1 influences the competitive strength of each bud by tuning how easily buds export auxin, while systemic auxin transport balances growth of the whole shoot system 14/n

a tree with lots of green leaves is against a white background

ALT: a tree with lots of green leaves is against a white background

media.tenor.com

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Zoe Nahas @zoenahas.bsky.social · 19d

We found that changing only the model parameter hypothesised to be BRC1 could predict largely accurately the effect of strigolactone on plants where PIN1 is insensitive to strigolactone (so where strigolactone is expected to act only/mostly through BRC1) 13/n

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Zoe Nahas @zoenahas.bsky.social · 19d

Throughout, we could test the effect of strigolactone independent of BRC1 by applying strigolactone to a brc1 mutant, but we couldn't do the same with PIN1 given the pin1 mutant is pleiotropic & doesn't even form axillary buds. So we made a chimeric PIN1 with impaired sensitivity to strigolact 12/n

Zoe Nahas @zoenahas.bsky.social · 19d

By varying two parameters representing the effects of strigolactone on (i) BRC1 & (ii) PIN1, the model could capture the competition outcomes and growth dynamics of many different 2-node mutants with varying BRC1 levels, with or without altered PIN1 🕺 11/n

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Zoe Nahas @zoenahas.bsky.social · 19d

So we built a mathematical model of interactions between 2 buds! As a simple self-activating and mutually-inhibiting system. If, as hypothesised, BRC1 affects background rate of bud auxin efflux, modifying this parameter in our model should reproduce the phenotypes of plants w/ altered BRC1 10/n

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Zoe Nahas @zoenahas.bsky.social · 19d

We wondered, can these two hypotheses account for the wide range of bud-bud interactions we observe in different mutants/treatments? But with 2 buds, branching outcomes are an emergent property of local and bud-bud regulation, w/ regulatory interactions that are feedback-driven so non-intuitive..9/n

a woman is looking at a triangle with the equation a = 1b / h written on it .

ALT: a woman is looking at a triangle with the equation a = 1b / h written on it .

media.tenor.com