Auxin group

Research topics

We study the molecular mechanism of polar auxin transport and how metabolic and transport processes regulate intracellular auxin homeostasis.

The plant hormone auxin is a key regulator of many developmental processes in plants. It governs the spatial and temporal aspects of plant growth, helping to coordinate and integrate development. Unlike other plant hormones, auxin is distinctive in that its molecules are transported over long distances in some tissues, and this transport is polar — directional, from cell to cell. The mechanism of this polar auxin transport is highly complex, regulated at multiple levels, and gives rise to auxin gradients (auxin maxima) within the plant. These gradients are shaped not only by intercellular transport but also by mechanisms regulating auxin homeostasis inside the cell — auxin transport across intracellular membranes together with the metabolic processes that interconvert its active and inactive forms.

Recent highlights

Auxin transport in phloem development. A long-running collaboration with the Hardtke laboratory (University of Lausanne) traces how polar auxin transport shapes the developing phloem: from discovering how a BRX–PAX–PIP5K module polarizes PIN carriers in sieve elements, through showing that ectopic assembly of this machinery redirects developmental trajectories, to our most recent finding that sieve element maturation is completed by a rapid, cell-to-cell auxin/PIN expulsion mechanism.

Auxin homeostasis and inactivation. We dissect how plants keep auxin levels in check by degrading it — from DAO-catalysed oxidation of IAA–amino acid conjugates to, more recently, how distinct GH3 enzyme subgroups route auxin inactivation through either aspartate or glutamine conjugation.

Evolutionary origins of auxin transport. With Stanislav Vosolsobě and Katarina Kurtović, we trace carrier-based auxin transport into the streptophyte algae. We established the alga Chara braunii as a tractable model and showed it possesses functional, IAA-responsive PIN-type transporters — pushing carrier-based auxin transport deeper into plant evolutionary history. This line also fed a broader phytohormone-profiling resource spanning the plant lineage.

Auxin habituation in cultured cells. We also ask why cultured cells lose their dependence on external auxin. Habituation involves upregulation of the auxin receptor TIR1, allowing proliferation independent of added hormone.

Team

Selected publications

Balakireva AV, Karataeva TA, Karampelias M, Mitiouchkina TY, Morozov VV, Macháček J, Shakhova ES, Perfilov MM, Belozerova OA, Kovalchuk SI, Palkina KA, Dražná N, Vondráková Z, Müller K, Kalachova T, Fleiss A, Fernandez-Moreno JP, Alonso JM, Stepanova AN, Fakhranurova LI, Markina NM, Gorbachev DA, Bugaeva EN, Delnova GM, Choob VV, Yampolsky IV, Petrášek J, Mishin AS, Sarkisyan KS (2026) Non-invasive imaging of defence responses in plants. Nature Communications, 17:6393. DOI: 10.1038/s41467-026-70075-1

Jelínková A, Dalecká M, Drs M, Müller K, Schmidt V, Kashkan I, Aliaga Fandino AC, Karampelias M, Malínská K, Li K, Knirsch M, Benda A, Petrášek J, Hardtke CS (2026) Rapid cell-to-cell expulsion completes phloem sieve element maturation. Current Biology. DOI: 10.1016/j.cub.2026.06.042

Helusová L, Ušák D, Havránková Z, Dobrev PI, Svobodová B, Talpová J, Brunoni F, Moravec T, Müller K, Petrášek J (2026) GH3 phylogenetic subgroups define divergent routes of auxin inactivation via aspartate and glutamine conjugation. Plant Physiology, kiag412. DOI: 10.1093/plphys/kiag412

Kurtović K, Petrášek J, Vosolsobě S (2025) Optimized laboratory maintenance and functional testing of Chara braunii. Current Protocols, 6(1): e70279. DOI: 10.1002/cpz1.70279

Jelínek P, Müller K, Kobercová E, Přibylová A, Čovanová M, Dobrev PI, Vaculíková R, Vondráková Z, Helusová L, Bírošíková A, Fischer L, Petrášek J (2026) A novel mechanism of auxin habituation: upregulation of auxin receptor TRANSPORT INHIBITOR RESPONSE 1 allows cell proliferation independent of external auxin. New Phytologist, 249(3): 1268-1282. DOI: 10.1111/nph.70763

Kurtović K, Vosolsobě S, Nedvěd D, Müller K, Dobrev PI, Schmidt V, Piszczek P, Kuhn A, Smoljan A, Fisher TJ, Weijers D, Friml J, Bowman JL, Petrášek J (2025) The role of indole-3-acetic acid and characterization of PIN transporters in complex streptophyte alga Chara braunii. New Phytologist, 246(3): 1066-1083. DOI: 10.1111/nph.70019

Schmidt V, Skokan R, Depaepe T, Kurtović K, Haluška S, Vosolsobě S, Vaculíková R, Pil A, Dobrev PI, Motyka V, Van Der Straeten D, Petrášek J (2024) Phytohormone profiling in an evolutionary framework. Nature Communications. DOI: 10.1038/s41467-024-47753-z

Aliaga Fandino AC, Jelínková A, Marhava P, Petrášek J, Hardtke CS (2024) Ectopic assembly of an auxin efflux control machinery shifts developmental trajectories. The Plant Cell. DOI: 10.1093/plcell/koae023

Kurtović K, Schmidt V, Nehasilová M, Vosolsobě S, Petrášek J (2023) Rediscovering Chara as a model organism for molecular and evo-devo studies. Protoplasma. DOI: 10.1007/s00709-023-01900-3

Müller K, Dobrev PI, Pěnčík A, Hošek P, Vondráková Z, Filepová R, Malínská K, Brunoni F, Helusová L, Moravec T, Retzer K, Harant K, Novák O, Hoyerová K, Petrášek J (2021) DIOXYGENASE FOR AUXIN OXIDATION 1 catalyzes the oxidation of IAA amino acid conjugates. Plant Physiology. DOI: 10.1093/plphys/kiab242

---

Serre NBC, Wernerová D, Vittal P, Dubey SM, Medvecká E, Jelínková A, Petrášek J, Grossmann G, Fendrych M (2023) The AUX1-AFB1-CNGC14 module establishes a longitudinal root surface pH profile. eLife. DOI: 10.7554/eLife.85193

El Houari I, Klíma P, Baekelandt A, Staswick PE, Uzunova V, Del Genio CI, Steenackers W, Dobrev PI, Filepová R, Novák O, Napier R, Petrášek J, Inzé D, Boerjan W, Vanholme B (2023) Non-specific effects of the CINNAMATE-4-HYDROXYLASE inhibitor piperonylic acid. The Plant Journal. DOI: 10.1111/tpj.16237

Kashkan I, Hrtyan M, Retzer K, Humpolíčková J, Jayasree A, Filepová R, Vondráková Z, Simon S, Rombaut D, Jacobs TB, Frilander MJ, Hejátko J, Friml J, Petrášek J, Růžička K (2021) Mutually opposing activity of PIN7 splicing isoforms is required for auxin-mediated tropic responses in Arabidopsis thaliana. New Phytologist. DOI: 10.1111/nph.17792

Vosolsobě S, Skokan R, Petrášek J (2020) The evolutionary origins of auxin transport: what we know and what we need to know. Journal of Experimental Botany. DOI: 10.1093/jxb/eraa169

Tan S, Di Donato M, Glanc M, Zhang X, Klíma P, Liu J, Bailly A, Ferro N, Petrášek J, Geisler M, Friml J (2020) Non-steroidal anti-inflammatory drugs target TWISTED DWARF1-regulated actin dynamics and auxin transport-mediated plant development. Cell Reports. DOI: 10.1016/j.celrep.2020.108463

Collaborators (recent and ongoing)

We highly appreciate the collaboration with other laboratories, in particular with

• Prof. Jiří Friml (IST Austria)
• Prof. Eva Benková (IST, Austria)
• Prof. Angus Murphy (University of Maryland, USA)
• Ass. Prof. Wendy Peer (University of Maryland, USA)
• Prof. Alain Gojon and Dr. Philippe Nacry (Institut de Biologie Intégrative des Plantes, CNRS/INRA, Montpellier, France)
• Prof. Richard M. Napier (School of Life Sciences, University of Warwick, UK)
• Prof. Christoph Ringli (Institute of Plant Biology, University of Zurich, Switzerland)
• Dr. Bartel Vanholme (Department of Plant Systems Biology, VIB, Ghent, Belgium)
• Prof. Martin Hof (J. Heyrovský Institute of Physical Chemistry, CAS, Prague)
• Assoc. Prof. Christian Luschnig (BOKU, Vienna, Austria)
• Assoc. Prof. Jürgen Kleine-Vehn (BOKU, Vienna, Austria)
• Prof. Christian S. Hardtke (University of Lausanne, Switzerland)
• Prof. Ondřej Novák (Palacký University & Institute of Experimental Botany, Laboratory of Growth Regulators, Olomouc, Czechia)