Delyan Zafirov

Fig. 1 (shortened, full legend in paper): Phosphorus availability tunes root architecture through TOR signaling. Pathways are represented without implying temporal or spatial sequence. Positive and negative regulation is denoted by arrowheads and flat-ended lines, respectively. (A) Nutrient control of TOR signaling. The TOR complex 1 (TORC1) integrates multiple mineral nutrient signals, including sulfur (S), nitrogen (N), phosphorus (P), iron (Fe), and potassium (K). Sulfate is transported via SULTRs, activating TOR. Nitrate, imported through NRTs, stimulates TOR via the ROP2 GTPase. Phosphate uptake through PHTs enhances ARSK1 expression and activity, which phosphorylates RAPTOR1B, activating TOR. Conversely, phosphate limitation lifts repression of PSR1 and ARSK1, which inhibits TORC. Iron is taken up via IRTs and eventually influences TORC activity.

🌱🧬 SPECIAL ISSUE REVIEW 🧬🌱

TORC1 integrates phosphorus and iron signals to regulate root architecture under stress, revealing key mechanisms of root plasticity and offering novel strategies to improve phosphorus use efficiency in crops – Choi et al.

🔗 doi.org/10.1093/jxb/...

#PlantScience 🧪

Pol II degradation activates cell death independently from the loss of transcription Pol II-mediated transcription is essential for eukaryotic life. While loss of transcription is thought to be universally lethal, the associated mechanisms promoting cell death are not yet known. Here,...

We just posted a preprint about a death mechanism that we find truly surprising.

When you turn off transcription, cells die (duh!)... but did you know this happens due to loss of Pol II itself, not loss of Pol II activity!?!

preprint here and a thread (1/n): www.biorxiv.org/content/10.1...
🧪

PELOTA at the Crossroads of Ribosome-associated quality control and Silencing: Coordinating Development, Stress, and Immunity in Plants Abstract. Ribosome-associated quality control (RaQC) pathways, including no-go decay (NGD) and non-stop decay (NSD), are essential for maintaining translat

❗️Excited to share our new review in J Exp Bot on PELOTA and ribosome-associated quality control in plants 🌱

We explore how translation surveillance connects with RNA silencing, development, and plant immunity.

Great work by PhD student Gemma Sans-Coll 👏

academic.oup.com/jxb/advance-...

Giant DNA viruses encode a hallmark translation initiation complex of eukaryotic life Giant DNA viruses encode a cap-binding complex homologous to eIF4F, the defining translation-initiation complex of eukaryotes. The viral cap-binding complex is required for viral protein synthesis and...

Giant DNA viruses encode a hallmark translation initiation complex of eukaryotic life: Cell www.cell.com/cell/fulltex...

The cover of Vol 77 | Issue 5 | 2026 of the Journal of Experimental Botany, Special Issue: Energy Management: Molecular Mechanisms and Signaling. Yellow coloured banners border the top and bottom of the page and in the centre the image depicts a whiteboard illustration of the original concept behind the workshop ‘Plant Energy Management: Molecular Mechanisms and Signalling,’ held at UPSC, Sweden, in August 2024. The aim was to expand upon the original TOR meeting by focusing on the inputs and outputs of the core energy management machinery in a species-agnostic manner. (Credit: Benoît Menand, Johannes Hanson, and Vanessa Wahl.)

📣 Check out JXB's newest Special Issue 📣
📘 Issue 5 of 2026 📘

⚡🌿 Energy Management: Molecular Mechanisms and Signalling 🌿⚡

📘 Guest edited by Benoît Menand, Johannes Hanson & Vanessa Wahl

🔗 academic.oup.com/jxb...

#JXBspecialissues #PlantScience 🧪 SEBiology

Immune activation suppresses reproductive growth in Arabidopsis through cytokinin signaling Johnston et al. report that defense hormones suppress cytokinin signaling, causing yield penalties. Restoring cytokinin in autoimmune plants relieves reproductive defects, confers broad pathogen resis...

Our beautiful work is out in Current Biology! @currentbiology.bsky.social

Immune activation suppresses reproductive growth in Arabidopsis through cytokinin signaling: Current Biology www.cell.com/current-biol...

Job vacancies: University of Hohenheim Current job opportunities at the University of Hohenheim

our cluster is searching for a technical assistant for supporting joint plant phenotyping experiments to be carried out at the University of Hohenheim
www.uni-hohenheim.de/en/job-openi...

Immune activation suppresses reproductive growth in Arabidopsis through cytokinin signaling Johnston et al. report that defense hormones suppress cytokinin signaling, causing yield penalties. Restoring cytokinin in autoimmune plants relieves reproductive defects, confers broad pathogen resis...

Immune activation suppresses reproductive growth in Arabidopsis through cytokinin signaling

www.cell.com/current-biol...

Reading one of the first publications documenting circadian rhythms in humans and it’s essentially two professors torturing an assistant prof.

so i guess not much has changed in academia in 130 years 🙃

Co-translational control of protein stability and quality in plants Abstract. Proteostasis relies on the coordinated control of protein synthesis, folding, modification and degradation, and an increasingly clear picture is

My review “Co-translational control of protein stability and quality in plants” is now online at @jxbotany.bsky.social, in which I describe how co-translational processing and ribosome-associated quality control together establish protein stability and fate early in synthesis. tinyurl.com/5dhhz9h6

RNA splicing generates a functionally specialized Rep protein isoform in geminiviruses — enabling timely control of the viral cycle. Strikingly, similar strategies might have evolved in DNA viruses infecting different kingdoms: www.biorxiv.org/content/10.6... Spearheaded by @delphinem-p.bsky.social!

@hanhtkvu.bsky.social @embl.org & we are looking for a #postdoc to study #regeneration x #autophagy across kingdoms of life. Pls spread the word & get in touch if you are interested www.health-life-sciences.de/opportunitie...

Cool story from @meristemania.bsky.social lab on growth-defense tradeoff at the shoot apical meristem www.biorxiv.org/content/10.6...

Recruitment of bifunctional regulator thermospermine to methylated ribosomes directs xylem fate Polyamines are often associated with ribosomes and are thought to stabilize their integrity. In Arabidopsis, the polyamine thermospermine (tSpm) affects xylem cell fate. tSpm induces translation of SU...

Recruitment of bifunctional regulator thermospermine to methylated ribosomes directs xylem fate | Science www.science.org/doi/10.1126/...

Great news: Marie Curie postdoctoral fellowships for Julia Baulies and @delyan.bsky.social funded. Looking forward to exciting work on root regeneration and TOR signaling, respectively!

Really excited about this - thanks for the support !

Looking to work with and learn from world-leading experts in plant cell imaging? I’ve got an open PhD position www.photobodies.com/about-6 in the framework of the AGILE Marie Curie Doctoral Network cordis.europa.eu/project/id/1...
Deadline: 15th of April, start date September 2026. #phd #job

Looking forward to meeting you at PEM2026 this summer, in beautiful Montpellier 🌱 Registration is open, join us! 👇🏼

Fluorescent proteins (mTurquoise2, mEGFP, mCitrine, mScarlet-I) move between cells via plasmodesmata in the epidermis of Nicotiana benthamiana. (Image credit: Rory Greenhalgh, Jacob O. Brunkard.)

🌱 SPECIAL ISSUE EDITORIAL 🌱

🔬 Plasmodesmata (PD) are membrane-lined channels in cell walls 🔬
In this editorial, Brunkard & Burch-Smith shift focus from "which molecules move through PD?" to "which molecules are *prevented* from moving through PD?" 🔎

🔗 doi.org/10.1093/jxb/...
#PlantScience 🧪

Root growth in Arabidopsis depends on the amount of glutathione and not the glutathione redox potential Abstract. Activity of the root apical meristem and hence plant growth strictly depends on glutathione homeostasis. Despite compelling evidence for this dep

Root growth in Arabidopsis depends on the amount of glutathione and not the glutathione redox potential academic.oup.com/jxb/article-... @jxbotany.bsky.social

Functional Characterization of Target of Rapamycin (TOR) Signalling in Physcomitrella Target of rapamycin (TOR) is a conserved protein kinase and an important signalling hub in eukaryotes. The moss Physcomitrella ( Physcomitrium patens ) is a model organism for plant physiology, develo...

Happy to share that our improved preprint
Functional Characterization of Target of Rapamycin (TOR) Signalling in Physcomitrella
has been accepted for publication. Stay tuned.
www.biorxiv.org/content/10.1...

mRNA methylation at the crossroads of translation, transport, and decay in plant development and stress responses Modified nucleotides on RNAs have been investigated for over six decades for their potential role in regulating gene expression and protein synthesis …

mRNA methylation at the crossroads of translation, transport, and decay in plant development and stress responses

www.sciencedirect.com/science/arti...

Indeed a great story illustrating how the plant TOR kinase can control the balance between growth and defense against pathogens !

Raffinose induces autophagy to promote the growth of Arabidopsis Thaliana - BMC Plant Biology Background Plant growth depends on the integration of environmental signals and nutrient availability. Under stress conditions, growth is often attenuated to prioritise defense, creating a trade-off b...

Excited to share our work about autophagy and raffinose. So proud of Sahar Magen for doing a great job and grateful for all the people who helped bring this work to light.
link.springer.com/article/10.1...

Great preprint by Liu, Blanford et al. (2025) on how trehalose 6-phosphate #T6P stimulates plant cell growth via #PlantTOR and is required for sucrose-induced TOR activation in #Arabidopsis by suppressing #SnRK1 in a dose-dependent manner, thereby mediating the antagonistic TOR–SnRK1 relationship.

Timing of transcription controls the selective translation of newly synthesized mRNAs during acute environmental stress Under stress, cells adapt their gene expression programs through changes in transcription and translation. It is unclear how cells determine which mRNAs are translated or repressed. Zedan et al. show that the timing of mRNA production alone determines the selectivity of translation, thereby coupling the processes of transcription and translation.

Timing of transcription controls the selective translation of newly synthesized mRNAs during acute environmental stress

AGO5 restricts virus vertical transmission in plant gametophytes The propagation of a viral infection from a host parent to its progeny is known as vertical transmission, or seed transmission in plants. It allows viral infections to rapidly spread locally via polle...

Preprint alert! It is my great pleasure to announce the first manuscript from the lab, a story that started @gmivienna.bsky.social and was mainly accomplished by the intrepid @gesahoffmann.bsky.social at @mpi-mp-potsdam.bsky.social. A brief thread with our findings
www.biorxiv.org/content/10.1...

A synthetic transcription cascade enables direct in planta shoot regeneration for transgenesis and gene editing in multiple plants #resource #MolecularPlant cell.com/molecular-pl...

Bioluminescent sentinel plants enable autonomous diagnostics of viral infections Plants engineered with synthetic genetic programs can transform how we monitor and manage the extension of crop pests and diseases. Here, we establish a bioluminescent platform in Nicotiana benthamian...

Such a cool pre-print on making sentinel plants - so much potential!

Bioluminescent sentinel plants enable autonomous diagnostics of viral infections

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

An important connection with the plant TOR signalling pathway!