#TIR1
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pierremarcdelaux.bsky.social
and we thought auxin signalling was "kind of solved"..

TIR1-produced cAMP is essential for auxin response (in Arabidopsis thaliana) 🔽

www.nature.com/articles/s41...
TIR1-produced cAMP as a second messenger in transcriptional auxin signalling - Nature
cAMP produced by the TIR1/AFB receptors of the main endogenous developmental plant hormone auxin acts as a true second messenger, revising the established paradigm of transcriptional auxin signalling.
www.nature.com
March 5, 2025 at 9:32 PM
apmahonen.bsky.social
Wow, cAMP production appears to be the key for activating canonical auxin signalling, not AUX/IAA degradation!

Also annoying - I need to revise quite a many teaching slides to update auxin signalling 😀
www.nature.com/articles/s41...
TIR1-produced cAMP as a second messenger in transcriptional auxin signalling - Nature
cAMP produced by the TIR1/AFB receptors of the main endogenous developmental plant hormone auxin acts as a true second messenger, revising the established paradigm of transcriptional auxin signalling.
www.nature.com
March 5, 2025 at 4:39 PM
mjprigge.bsky.social
The second new paper from the Estelle lab out this week describes the phenotype of moss lines lacking all seven Class-A ARFs (Activating ARFs) and was lead former postdoc Carlisle Bascom, Jr.
academic.oup.com/jxb/advance-...
Figure 1 from Bascom et al JEXBOT comparing the arfa-septuple mutant's growth to that of WT, tir1/afb-quad, and iaa2-degron. The arfa mutant's phenotype is strong but less severe than those of the tir1/afb and iaa2 mutants.
May 5, 2025 at 10:39 PM
mjprigge.bsky.social
I also donated TIR1-mOrange2, AFB1-mECFP, AFB3-mEGFP, AFB5-mCherry, and iaa6-C78R lines
May 12, 2026 at 7:28 AM
onasu29.bsky.social
限定商品は食べずにはいられない
今回のは全部Tir1です
大当たりです
June 21, 2025 at 3:39 AM
meera-sundaram.bsky.social
#worm25 since I missed the first plenary session due to flight delays I’ve been catching up by watching it online - Cool talk from Roger Pocock! The individual neuron-specific TIR1 strains will be an amazing tool - And I love the term « Hobertian »! 😂
July 9, 2025 at 2:41 PM
mjprigge.bsky.social
Here's a comparison I use to introduce phenotypes of moss grown on auxin & NH4.
Comparison of wild type, tir1/afb-, and aux/iaa- moss (Physcomitrium patens) grown for 21 days on BCD medium and BCD supplemented with ammonium tartrate or auxin. The mutants look the same ±auxin, but NH4 enhances the tir1/afb mutant and suppresses the aux/iaa mutant.
November 28, 2024 at 12:10 AM
biorxiv-plants.bsky.social
TOW links TIR1/AFB-mediated signalling with Receptor-Like Kinases in auxin canalization https://www.biorxiv.org/content/10.1101/2025.04.25.650570v1
April 29, 2025 at 2:18 PM
mjprigge.bsky.social
Uh oh, we just noticed that the "OsTIR1" used in hundreds of papers using Auxin-Induced Depletion (AID) is actually OsAFB2 not the TIR1 ortholog.
March 27, 2025 at 9:16 PM
cp-trendsplantsci.bsky.social
Role of cAMP in TIR1/AFB auxin signaling: open issues #plantscience
Role of cAMP in TIR1/AFB auxin signaling: open issues
The canonical mechanism by which the phytohormone auxin regulates transcription has been one of the cornerstones of plant signaling. The recent unexpected discovery of cyclic AMP (cAMP) as a second messenger in this pathway has revised its foundations while leaving many open questions and gaps in our understanding; these will be discussed in this forum article.
dlvr.it
November 17, 2025 at 1:41 PM
sshadan.bsky.social
While work @nature recently showed that the TIR1/AFB receptors of the plant hormone auxin have adenylate cyclase activity, further work now shows the broad physiological significance of this activity during plant development, via transcriptional reprogramming.

www.nature.com/articles/s41...
TIR1-produced cAMP as a second messenger in transcriptional auxin signalling - Nature
cAMP produced by the TIR1/AFB receptors of the main endogenous developmental plant hormone auxin acts as a true second messenger, revising the established paradigm of transcriptional auxin signalling.
www.nature.com
March 5, 2025 at 4:03 PM
iebcas.bsky.social
#new_paper: A novel mechanism of auxin habituation: upregulation of auxin receptor TRANSPORT INHIBITOR RESPONSE 1 allows cell proliferation independent of external auxin
@newphyt.bsky.social: auxin, auxin autonomy, cell division, cell line, habituation, Nicotiana tabacum,TIR1
doi.org/10.1111/nph....
December 10, 2025 at 10:38 AM
cp-trendsplantsci.bsky.social
Decoding dialog: the auxin–calcium signaling crosstalk in plants #plantscience
Decoding dialog: the auxin–calcium signaling crosstalk in plants
Auxin and calcium (Ca2+) are central plant signals that coordinate growth, development, and responses to environmental cues. Typically studied as largely parallel pathways, they are now increasingly recognized as interconnected networks whose activities converge at multiple regulatory levels. Recent advances in live imaging, biosensors, optogenetics, and structural approaches have revealed that auxin can rapidly trigger Ca2+ influx from the apoplast via TRANSPORT INHIBITOR RESPONSE1 (TIR1)/AUXIN-SIGNALING F-BOX (AFB)-dependent signaling mechanisms and Ca2+ channels, presumably involving cyclic nucleotides produced by TIR1/AFB auxin receptors. Conversely, Ca2+ signals arising from mechanosensing, wounding, and environmental stress can modulate auxin transport, signaling, and transcriptional outputs. Together, these discoveries highlight a dynamic, reciprocal signaling axis where Ca2+ acts both downstream and upstream of auxin to shape growth, development, tropisms, and regeneration.
dlvr.it
September 4, 2026 at 12:40 PM
stvanneste.bsky.social
Forgot to quote...

#auxin, habitation in tobacco cell suspensions. I might need to check my TIR1 expression too, after all these years 😉
newphyt.bsky.social New Phytologist @newphyt.bsky.social · Dec 10
High expression of TIR1 stimulates plant cell proliferation by enhancing sensitivity to auxin

Jelínek et al. @iebcas.bsky.social

nph.onlinelibrary.wiley.com/doi/10.1111/...
Endogenous levels of indole-3-acetic acid in auxin-habituated lines.
December 11, 2025 at 7:22 PM
biorxiv-plants.bsky.social
Guanylate cyclase activity of TIR1/AFB auxin receptorsin rapid auxin responses https://www.biorxiv.org/content/10.1101/2023.11.18.567481v1
Guanylate cyclase activity of TIR1/AFB auxin receptorsin rapid auxin responses https://www.biorxiv.org/content/10.1101/2023.11.18.567481v1
The major developmental signal in plants, auxin is perceived by TIR1/AFB receptors. It triggers tran
www.biorxiv.org
November 19, 2023 at 2:06 AM
istaresearch.bsky.social
Check out this recent preprint:

doi.org/10.1101/2025...
Nuclear auxin signalling induces autophagy for developmental reprogramming
The phytohormone auxin is a central regulator of plant growth and development, traditionally known for mediating transcriptional reprogramming through the canonical TIR1/AFB-Aux/IAA signalling pathway...
doi.org
November 12, 2025 at 12:37 PM
ingen15godzzil2.bsky.social
おれの料理レパートリーが至っていなかっただけで、スーパーに並ぶレベルの子ってみんな主役張れる強さのTir1食材だったりするのか？もしかして
January 19, 2025 at 10:10 AM
meristemania.bsky.social
Paradigm shifting work from the Friml lab - degradation of auxin response repressors is not causal for the transcriptional reprogramming, cAMP signaling is - awesome read! www.nature.com/articles/s41...
TIR1-produced cAMP as a second messenger in transcriptional auxin signalling - Nature
cAMP produced by the TIR1/AFB receptors of the main endogenous developmental plant hormone auxin acts as a true second messenger, revising the established paradigm of transcriptional auxin signalling.
www.nature.com
March 6, 2025 at 1:19 PM
jxbotany.bsky.social
🚦🌍🧬 REVIEW 🧬🌍🚦

This review synthesizes plant 3',5'-cAMP signaling networks, from homeostatic enzymes to downstream effectors, and their role in integrating environmental responses with development – Luo et al.

🔗 doi.org/10.1093/jxb/...

#PlantScience 🧪
Fig. 3.Schematic representation of the crosstalk between cAMP and phytohormone signaling pathways. Abbreviations: TIR1/AFB, Transport Inhibitor Response 1/Auxin Signaling F-Box Protein; NCED3, 9-cis-epoxycarotenoid dioxygenase 3; ABA, abscisic acid; IAA, indole-3-acetic acid; JA, jasmonic acid; SA, salicylic acid; GA, gibberellin; CK, cytokinin; TAA1, Tryptophan Aminotransferase of Arabidopsis 1; YUC, YUCCA; MYC2, Myelocytomatosis 2; CNGC2, Cyclic Nucleotide-Gated Ion Channel 2.
March 22, 2026 at 9:30 AM
karimaelm.bsky.social
Wow 🤩🤩
"...degradation of Aux/IAAs is not sufficient for the transcriptional signalling.
In contrast, cAMP production seems sufficient to activate transcription of auxin-regulated genes."
Love reading papers that revisit well-established mechanisms !

www.nature.com/articles/s41...
TIR1-produced cAMP as a second messenger in transcriptional auxin signalling - Nature
cAMP produced by the TIR1/AFB receptors of the main endogenous developmental plant hormone auxin acts as a true second messenger, revising the established paradigm of transcriptional auxin signalling.
www.nature.com
March 5, 2025 at 5:50 PM
barrlab.bsky.social
DAF-2/IGF-1 degradation: Males WAY outlive hermaphrodites! This is so cool. @patrickphillips.bsky.social
Fig. 1 Ubiquitous and tissue-specific DAF-2 degradation extends male lifespan. (a) Kaplan- Meier curves showing survival of C. elegans hermaphrodites and males following ubiquitous DAF-2 degradation. Purple lines denote hermaphrodites and green lines denote males. Dashed lines denote the negative controls (TIR1-only on auxin) and solid lines denote DAF-degradation with 1mM auxin treatment. Each line represents at least two biological replicates with total n = 183–235.
November 7, 2025 at 9:41 PM
adernburg.bsky.social
Work from Mark Estelle and others identified mutations in the Arabidopsis TIR1 protein that block its interaction with Cullin 1. We leveraged this information to repurpose the AID system as an auxin-inducible dimerization system.
October 29, 2023 at 5:41 PM
newphyt.bsky.social
Nuclear auxin signaling and temperature: perception and response across scales

#TansleyInsight by Sageman-Furnas and Strader @luciastrader.bsky.social

nph.onlinelibrary.wiley.com/doi/10.1111/...

#plantscience
The figure is a horizontal schematic illustration how auxin signaling may act across scales from biophysical to whole plant. From left to right the figure contains 7 representative stages, 1: IDR dynamics represented by a loosely drawn cartoon of a molecular structure, 2: Binding dynamics, represented by two cartoons of the proteins TIR1 and Aux/IAAs, 3: Protein stability, represented by a cartoon of the 26s proteasome, 4: Nucleo-cytoplasmic partitioning, represented by a simplified cell with ARF7 proteins in the cytosol and the nucleus, 5: Signal transduction, represented by a schematic of activated transcription of auxin biosynthesis genes by PIF4, 6: Auxin homeostasis and transport, represented by a schematic of auxin conjugation and a simplified cell with arrows representing auxin movement between cells, and 7: Thermomorphogenesis, represented by two seedlings growing at 22º and 28º, with the seedlings at 28 degrees having longer hypocotyls and roots.
August 17, 2026 at 12:02 PM
spicybotrytis.bsky.social
We often ignore literature and citations in niche fields leading us to ask for experiments that have been done when reviewing those fields. It is as if it was okay to say "Nothing in the manuscript directly shows that auxin binds TIR1 and this needs to be validated."
February 11, 2025 at 6:55 PM
somssich.bsky.social
📜 FERONIA-mediated TIR1/AFB2 oxidation stimulates auxin signalling in Arabidopsis

🧑‍🔬 Baiyan Lu, Chao Li, et al.

📔 Molecular Plant

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

#️⃣ #PlantScience #Phytohormones #PlantSignalling #Auxin #Feronia
FERONIA-mediated TIR1/AFB2 oxidation stimulates auxin signalling in Arabidopsis
The phytohormone auxin plays a pivotal role in governing plant growth and development. While the TRANSPORT INHIBITOR RESPONSE1/AUXIN SIGNALING F-BOX (…
www.sciencedirect.com
April 8, 2024 at 7:37 AM