Mélanie Rich 🌱🍄

1/ ✨ New preprint alert ✨

It is my pleasure to share:
"Stepwise evolution of the developmental and symbiotic functions of DELLA in land plants"

Here we investigated the role of the single GRAS transcription factor DELLA in #MyMarchantia

doi.org/10.64898/202...

#PlantScience
A thread...

A huge THANK YOU to all co-authors @pierremarcdelaux.bsky.social @melaniekrich.bsky.social @mbianc.bsky.social @kellerjeanphd.bsky.social & more ! We are grateful for our funders @dfg.de @erc.europa.eu MSCA @agencerecherche.bsky.social

A THREAD, which I am calling 'Some Of The Many Reasons Lichen And Moss Are Fucking Brilliant'.

1. They make public seating super comfy.

bsky.app/profile/dj-a...

📺 Sur CNews, un cas de désinformation climatique est recensé toutes les heures !

Depuis janvier, @quotaclimat.org, @dataforgoodfr.bsky.social et @sciencefeedback.bsky.social ont recensé 529 cas de désinformation climatique dans les médias audiovisuels. Plus d'infos 👉 vert.eco/articles/529...

Exploring fern pathosystems and immune receptors to bridge gaps in plant immunity - BMC Biology Land plants include angiosperms, gymnosperms, bryophytes, lycophytes, and ferns, each of which may deploy distinct strategies to resist pathogens. Here, we investigate fern-pathogen interactions by characterizing novel pathosystems and analyzing the diversity of fern immune receptors. A collection of fern species was inoculated with a diverse set of filamentous microbes, and disease symptoms were assessed. We further leveraged published genome mining tools to analyse the diversity of receptor-like kinases, receptor-like proteins (RLKs/RLPs) and nucleotide-binding and leucine-rich repeats (NLRs), along with key immune signalling components, in ferns. Our results reveal that ferns exhibit a range of responses to pathogens, including putative non-host resistance and more specific resistance mechanisms. Among ten ferns tested, Pteris vittata displays the broadest spectrum of pathogen compatibility. Genome mining indicates that ferns encode a diverse repertoire of putative immune receptors, antimicrobial peptides, and mediators of systemic acquired resistance. Ferns possess numerous RLKs/RLPs, resembling those required for cell-surface immunity in angiosperms. They also encode diverse NLRs, including sub-families lost in flowering plants. These findings provide insights into disease resistance evolution and open promising perspectives for crop protection strategies.

1\ bmcbiol.biomedcentral.com/articles/10....
🌿🌿Our article on fern immunity has been peer-reviewed 🌿🌿
Thanks to @madeleinebaker.bsky.social @kellerjeanphd.bsky.social @maximebonhomme.bsky.social @pierremarcdelaux.bsky.social and @jacquet-chris.bsky.social

a quick thread 🧵 1/4

Have you ever wondered why pumpkins are never purple or blue like other plants? 🎃🌈

While most plants can produce pink, blue, and purple pigments (thanks to anthocyanins), the Cucurbitaceae family 🍈 🍉 🥒have lost all the pathway genes to produce these pigments.
🔗 doi.org/10.1101/2025...

A first dive in fern x pathogen interaction! More to come!

Congratulations @baptistebio.bsky.social @jacquet-chris.bsky.social et al.!

Various ferns species inoculated with S. sclerotiorum.

Want to see ferns under attack and how they respond to pathogens? Check out our latest paper!
doi.org/10.1186/s129...
Congrats on this huge team effort to @baptistebio.bsky.social @madeleinebaker.bsky.social @kellerjeanphd.bsky.social @maximebonhomme.bsky.social @pierremarcdelaux.bsky.social

This was indeed a fun read! Nothing makes you feel stupid as much as trying to read a paper out of your scope of knowledge

I wished I could have written something like this. Rude, fun and meaningful.
static1.squarespace.com/static/686d9...

Congratulation to our colleagues for this amazing work!

Thank you for the 🧵 ! Tagging for the #PlantScience feed!

~12 years after we coined it EPP1 with @oswaldovaldesl.bsky.social one afternoon when we were postdoc with @jeanmichelane.bsky.social!

Congrats @melaniekrich.bsky.social @tatiana-vernie.bsky.social et al. for the hard work!

EPP1 is the fourth member of the Common Symbiosis Pathway 🍄🌱!

What Everyone Should Know About Fungi by Age 15

5️⃣ Mycorrhizal fungi are often first responders post wildfires, droughts, and human disturbances, helping plants regenerate, rebuild root systems & reestablish nutrient pathways.

See the top 10 list (buff.ly/nMNaB60) and follow for new fungal facts.

Really glad to share this team work

Schematic representation of the Common Symbiosis Pathway. The plasma membrane receptor SYMRK phosphorylates EPP1, this leads to a calcium spiking activation of the kinase CCaMK that in turn phosphorylates the transcription factor CYCLOPS to activate the symbiotic program

Together with new data in RNS from our colleagues @nikolajabel.bsky.social et al. doi.org/10.1101/2025..., we hope close the gap in our understanding of the common symbiosis pathway for plant endosymbioses! 7/7

EPP1 is an ancestral component of the plant Common Symbiosis Pathway The success of plants on land has been enabled by mutualistic intracellular associations with microbes for 450 million years ([Delaux and Schornack 2021][1]). Because of their intracellular nature, th...

www.biorxiv.org/content/10.1...
and
www.biorxiv.org/content/10.1...

Two papers to tell us more about mysterious EPP1, a protein required for symbiosis. Well done @tatiana-vernie.bsky.social and all co-authors.

We propose that EPP1 has been a core component of AMS signaling since the origin of land plants as we know them 🌱🍄 6/7

Here we show abolition of AMS in epp1 mutants in the flowering plant Petunia and in the liverwort Marchantia. We also find that EPP1 is directly phosphorylated by the SYMRK receptor and that the epp1 phenotype can be complemented by an autoactive version of the kinase CCaMK 5/7

Knowing EPP1 belongs to the short list of genes conserved across land plants in species with the ability to form endosymbiosis and convergently lost in the ones having lost this ability, we decided switch model plants to test the function of EPP1 in Arbuscular Mycorrhiza Symbiosis (AMS). 4/7

A Novel Positive Regulator of the Early Stages of Root Nodule Symbiosis Identified by Phosphoproteomics Abstract. Signals and signaling pathways underlying the symbiosis between legumes and rhizobia have been studied extensively over the past decades. In a pr

Previously, Early Phosphorylated Protein 1 (EPP1) was suggested to play an essential role in Root Nodule Symbiosis but the high copy number of EPP1 genes in Medicago (4!) limited our ability to study its function doi.org/10.1093/pcp/... doi.org/10.1111/nph.... . 3/7

With @tatiana-vernie.bsky.social @mbianc.bsky.social @baptistebio.bsky.social @kellerjeanphd.bsky.social @malick-mbengue.bsky.social @pierremarcdelaux.bsky.social and many others 2/7

EPP1 is an ancestral component of the plant Common Symbiosis Pathway The success of plants on land has been enabled by mutualistic intracellular associations with microbes for 450 million years ([Delaux and Schornack 2021][1]). Because of their intracellular nature, th...

So happy to see the latest preprint of the team out! www.biorxiv.org/content/10.1...
The continuation of a long standing project started by @oswaldovaldesl.bsky.social in @jeanmichelane.bsky.social‘s lab. 1/7 🧵

A Novel Positive Regulator of the Early Stages of Root Nodule Symbiosis Identified by Phosphoproteomics Abstract. Signals and signaling pathways underlying the symbiosis between legumes and rhizobia have been studied extensively over the past decades. In a pr

For more information: academic.oup.com/pcp/article/...
nph.onlinelibrary.wiley.com/doi/10.1111/...

Our findings suggest that EPP1 serves as a key molecular bridge between plasma membrane signaling and downstream responses doing root nodule symbiosis, helping to close a long-standing gap in the field.
Congratulations to everyone involved in this work!

EPP1 couples receptor activation to cytoplasmic signaling in root nodule symbiosis Legume symbiosis with nitrogen-fixing bacteria is controlled by a cascade of signaling events leading to root nodule development. While plant cell-surface receptors initiate this process, the link bet...

We’re thrilled to share our latest preprint!
In this study we provide a mechanistic insight into how the protein EPP1 (first identified in Rose et al., 2012) functions in partnership with SYMRK.
www.biorxiv.org/content/10.1...

Multi-generational vulture nests hold 700 years of human artifacts Crossbow bolts, sandals, slingshots, and more.

super cool study found human artifacts in Bearded vulture nests, incl. "weaponry like a crossbow bolt and wooden lance, decorated sheep leather, and parts of a slingshot....a shoe made from twigs and grass is ~675-years-old." link to paper: doi.org/10.1002/ecy..... www.popsci.com/environment/... 🧪🌍🦉

EPP1 is an ancestral component of the plant Common Symbiosis Pathway The success of plants on land has been enabled by mutualistic intracellular associations with microbes for 450 million years (Delaux and Schornack 2021). Because of their intracellular nature, the est...

Fantastic work from @pierremarcdelaux.bsky.social annd col. expanding the basic genetic toolkit enabling symbiotic interactions in plants www.biorxiv.org/content/10.1...

EPP1 is an ancestral component of the plant Common Symbiosis Pathway The success of plants on land has been enabled by mutualistic intracellular associations with microbes for 450 million years (Delaux and Schornack 2021). Because of their intracellular nature, the est...

www.biorxiv.org/content/10.1...
Great story in collaboration with @pierremarcdelaux.bsky.social and @jeanmichelane.bsky.social groups. EPP1 story continues after many years of collaborations with Pierre-Marc and Jean-Michel!!!

I repeat, the Common Signalling pathway for symbiosis is on fire! Kudos to our colleagues from Toulouse 🍄🌿