Thanks Jean-Michel!!!

Beyond nitrogen: phosphate controls root nodule symbiosis commitment While root nodule symbiosis (RNS) is primarily recognized for nitrogen acquisition, it is heavily influenced by phosphorus levels. In natural agroecosystems, nitrogen limitation frequently co-occurs with phosphorus deficiency, yet the role of phosphorus in modulating RNS remains understudied. Recent research in the legume Phaseolus vulgaris shows that phosphorus starvation suppresses nodulation by downregulating the master regulator gene Nodule Inception, mediated by phosphate-responsive factors such as Phosphate Starvation Response-Like 7. We propose an integrated model where phosphate signaling functions as a metabolic checkpoint, balancing carbon availability, nitrogen demand, and phosphorus status. Elucidating how phosphate scarcity rewires these symbiotic gene networks is essential for sustainable agriculture, allowing for the optimization of symbiotic nitrogen fixation in nutrient-depleted environments.

Great review from @iamjawaharsingh.bsky.social, @oswaldovaldesl.bsky.social and @dromius.bsky.social in @cp-trendsplantsci.bsky.social -> Beyond nitrogen: phosphate controls root nodule symbiosis commitment

Beyond nitrogen: phosphate controls root nodule symbiosis commitment While root nodule symbiosis (RNS) is primarily recognized for nitrogen acquisition, it is heavily influenced by phosphorus levels. In natural agroecosystems, nitrogen limitation frequently co-occurs with phosphorus deficiency, yet the role of phosphorus in modulating RNS remains understudied. Recent research in the legume Phaseolus vulgaris shows that phosphorus starvation suppresses nodulation by downregulating the master regulator gene Nodule Inception, mediated by phosphate-responsive factors such as Phosphate Starvation Response-Like 7. We propose an integrated model where phosphate signaling functions as a metabolic checkpoint, balancing carbon availability, nitrogen demand, and phosphorus status. Elucidating how phosphate scarcity rewires these symbiotic gene networks is essential for sustainable agriculture, allowing for the optimization of symbiotic nitrogen fixation in nutrient-depleted environments.

Beyond nitrogen: phosphate controls root nodule symbiosis commitment #plantscience

New Opinion with @iamjawaharsingh.bsky.social @oswaldovaldesl.bsky.social in @cp-trendsplantsci.bsky.social
No Phosphate, less nitrogen fixing symbiosis and nodules, regardless of nitrogen status. PHR-L7 represses NIN in Common bean under phosphate starvation.
www.sciencedirect.com/science/arti...

Very useful protocol from @kathschiessl.bsky.social. Thank you!  -> Spatiotemporal analysis of cell division during symbiotic root nodule development in the model legume Medicago truncatula

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The root nodule symbiosis regulator NIN exhibits broad DNA binding specificity conferred by an NLP-inherited motif

Ané Lab Jean-Michel Ané

2 postdoc openings in my lab:
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One for a maize geneticist and one for a bacterial geneticist

Picture featuring @manishbiotechie.bsky.social, @balptekin.bsky.social and @sairamnagalla.bsky.social. The first two left my lab over the last few months to start their own labs!

schematic diagram showing phosphate starvation responses (PSR) and how they regulate nodulation and AM symbiosis in 3 plant species: Arabidopsis thaliana, P. vulgaris, and M. truncatula. Taken from Batnini and Kumar (https://doi.org/10.1093/pcp/pcaf133) in their Commentary to: Singh, J., Mendoza-Soto, A. B., Tiwari, M., Acevedo-Sandoval, T. T., Formey, D., Ané, J.-M., Isidra-Arellano, M. C., & Valdés-López, O. (2025). Phosphate deficiency reduces nodule formation through a phosphate starvation response-like protein in Phaseolus vulgaris. Plant and Cell Physiology. https://doi.org/10.1093/pcp/pcaf069.

Feeding symbiosis...

Singh @oswaldovaldesl.bsky.social et al show that the PHR-L7 transcription factor in common bean halts early nodulation under P-scarce conditions, linking nutrient availability with #nodulation

🔗 doi.org/10.1093/pcp/...

Commentary & Fig: doi.org/10.1093/pcp/...

#PlantScience

Thanks for sharing this!!

Nutrient-symbiosis cross talk links phosphate starvation signaling with nodulation control Phosphate (Pi) is one of the most important nutrients for plant growth and productivity, as it is an essential building block for a wide range of biomolecules. However, Pi is often poorly available in soils because of its low mobility and tendency to bind strongly to soil particles (Wang et al. 2025). This limitation poses a particular challenge for legumes, where symbiotic nitrogen fixation in root nodules demands high energy and phosphorus inputs. Under Pi limitation, nodules number is tightly regulated through the long-distance signaling pathway called autoregulation of nodulation (AON) to avoid an energetic imbalance (Isidra-Arellano and Valdes-López 2024). Although phosphate starvation responses (PSR) are well-characterized, the precise mechanisms by which Pi status is directly integrated into the genetic control of rhizobial nodulation have remained unclear.

Very nice commentary on @oswaldovaldesl.bsky.social's recent paper -> Nutrient-symbiosis cross talk links phosphate starvation signaling with nodulation control

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Plz RP. Come join us at @slcuplants.bsky.social @cam.ac.uk to study effector-targeted plant processes impacting plant cell biology and development.
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9/ Altogether our work demonstrates that ERS clade transcription factors have been acting as the transcriptional link between the CSP and the infectosome since the most recent common ancestor of land plants.

10/ A huge THANK YOU to all co-authors for the amazing team effort! We are grateful for our funders @erc.europa.eu MSCA @dfg.de @agencerecherche.bsky.social

Symbiotic diversification relies on an ancestral gene network in plants Symbioses have been fundamental to colonization of terrestrial ecosystems by plants and their evolution. Emergence of the ancient arbuscular mycorrhizal symbiosis was followed by the diversification o...

1/ It is my pleasure to share the latest preprint of the team: "Symbiotic diversification relies on an ancestral gene network in plants"

doi.org/10.1101/2025...

Here, we identified and functionally validated a novel master regulator of intracellular symbioses!

A thread ...
#PlantScience

Starve or share? Phosphate availability shapes plant–microbe interactions Phosphorus is an essential macronutrient that supports core biological processes such as photosynthesis, respiration, and the biosynthesis of nucleic acids and membranes [1]. Plants take up phosphorus from the soil as inorganic orthophosphate (Pi) [2], yet Pi is poorly available in most soils due to its rapid fixation into insoluble complexes with iron and aluminium in acidic soils, and calcium in alkaline soils [3]. Consequently, Pi availability is a major limitation for plant growth and crop productivity [3]. To cope with Pi deficiency, plants have evolved a highly coordinated network of local and systemic phosphate starvation responses (PSRs) that are rapidly reversed upon Pi resupply. These PSRs involve morphological, transcriptional, and metabolic adjustments. Local responses primarily reshape root system architecture (e.g., inhibition of primary root growth, root hair formation and lateral root formation), systemic responses aim to maintain Pi homeostasis through improved Pi uptake, recycling, and utilisation [3]. In Arabidopsis, systemic PSRs are orchestrated by the MYB-type coiled-coil transcription factor Phosphate Response 1 (PHR1; [4]) and its homologues PHR1-likes (PHLs; [5–7], and orthologs have been described in several plant species [8–12] (Fig 1). These transcription factors activate Pi starvation-induced (PSI) genes by binding to the PHR1 Binding Sequence (P1BS) in their promoters [4] (Fig 1A). Among the targets are genes encoding high-affinity Pi transporters and enzymes involved in membrane phospholipids remodelling [3,5,13,14]. PHR activity is tightly regulated by SYG1/Pho81/XPR1 (SPX) domain-containing proteins. SPX domains act as high-affinity receptors for inositol pyrophosphates (PP-InsPs), which serve as proxies for cellular Pi status and mediate the interaction between SPX and PHR [15–17] thereby inhibiting PHR by sequestering it away from the nucleus or DNA [18–22] (Fig 1A). Interestingly, Pi signalling is not isolated but tightly interconnected with nitrogen status. In rice, under high nitrate conditions, the nitrate sensor Nitrate Transporter 1.1B (NRT1.1B; [23]) interacts with SPX4, promoting SPX4 degradation via the E3 ligase NRT1.1B interacting protein 1 (NBIP1; [24]). As a result, PHR2 and NIN-like protein 3 (NLP3; [25]) are released from SPX-mediated inhibition, translocate into the nucleus and activate PSI and nitrate-response genes, respectively [24]. In Arabidopsis, the expression of several PSI genes is reduced in an nrt1.1 mutant and is influenced not only by Pi but also by nitrate availability [26]. Furthermore, PHR1 and NLPs regulate the expression of Nitrate-Inducible GARP-type Transcriptional Repressor 1 (NIGT1) genes, which encode repressors of specific nitrate-response genes [27] as well as SPX genes [28]. These examples illustrate the tight interconnection between Pi and nitrate signalling, which has been comprehensively reviewed elsewhere [29,30]. MicroRNAs, particularly miR399 and miR827, add additional layers of regulation by downregulating negative regulators of Pi uptake, contributing to a robust and multi-tiered response system [31–35]. Notably, the SPX–PHR regulatory module is evolutionarily conserved across land plants, including early diverging lineages such as Marchantia polymorpha, highlighting its fundamental role in signalling [36].

Nice review from @oswaldovaldesl.bsky.social, Martina Ried and coll.  - > Starve or share? Phosphate availability shapes plant–microbe interactions

Starve or share? Phosphate availability shapes plant–microbe interactions

New review paper in collaboration with Martina Ried

Starve or Share? Phosphate availability shapes plant-microbe interactions

journals.plos.org/plospathogen...

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!!!

Stop displaying journal names on your slides A mentoring event at a scientific Congress called for better support of early-career scientists — but what followed sent mixed signals…

I just published: Stop displaying journal names on your slides

A mentoring event at a Congress called for better support of early-career scientists - but what followed sent mixed signals. This blog reflects on those moments and ends with a pledge.

medium.com/p/stop-displ...

Meet the Scientists Making Chickpeas Tastier and Healthier! YouTube video by Good Day Sacramento

For those of you who know Doug Cook from UC Davis:
www.youtube.com/watch?v=mXJu...

Happy to share our latest manuscript from our lab in collaboration with @jeanmichelane.bsky.social

Phosphate deficiency reduces nodule formation through a Phosphate Starvation Response -Like protein in Phaseolus vulgaris url: academic.oup.com/pcp/article/...

What will happen when we run out of phosphorous? 🥀

@hatem-rouached.bsky.social talks about ARSK1 & TORC1 interactions to regulate growth under P-deficiency #ICAR2025

See also review on the effects of low P on root nodule symbiosis by @oswaldovaldesl.bsky.social

🔗 doi.org/10.1093/pcp/...

Postdoctoral Fellowship in Mexico

Understanding the Crucial Role of Phosphate and Iron Availability in Regulating Root Nodule Symbiosis Abstract. The symbiosis between legumes and nitrogen-fixing bacteria (rhizobia) is instrumental in sustaining the nitrogen cycle and providing fixed nitrog

Feeding symbiosis...

Isidra-Arellano & @oswaldovaldesl.bsky.social provide insight into the influence of phosphate & iron uptake and homeostasis on root nodule symbiosis, and how this could be harnessed for more efficient nitrogen fixation in legume crops.

📖 doi.org/10.1093/pcp/...

#plantscience

Schematic diagram showing active/inactive SL receptors and their roles in distinct SL signaling pathways in the facultative parasitic plant, P. japonicum.

Back-to-back #strigolactone perception...

In this issue academic.oup.com/pcp/issue/65..., two papers by Takei et al. & White et al. shed light on the diverse roles of KAI2 SL receptors in a facultative #parasiticplant

Commentary by PCP Editor, Satoko Yoshida doi.org/10.1093/pcp/...

#plantscience

Conservation of symbiotic signaling since the most recent common ancestor of land plants | PNAS Plants have colonized lands 450 million years ago. This terrestrialization was facilitated by developmental and functional innovations. Recent evo-...

Really pleased to transition from 2024 to 2025 with Tatiana Vernie's work on the evolution of the common symbiosis pathway published @pnas.org 🔽

We finally demonstrate that ☘️ have maintained a genetic pathway to engage with🍄for half a billion years!

www.pnas.org/doi/10.1073/...

CEP signaling coordinates plant immunity with nitrogen status - Nature Communications Rzemieniewski et al. demonstrated that Arabidopsis thaliana CEPs regulate immunity via three CEP receptors with distinct expression patterns and ligand specificities. CEPs and their receptors coordina...

📜 CEP signaling coordinates plant immunity with nitrogen status

🧑‍🔬 Jakub Rzemieniewski, Martin Stegmann, et al.

📔 @naturecomms.bsky.social

🔗 www.nature.com/articles/s41...

#️⃣ #PlantScience #PlantNutrition #PlantImmunity #PlantSignaling

Hi everyone!! We are excited to be here as a community of scientists working on #plantscience ☘️🌱 and their associated microbes 🍄 !

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