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PIN-driven auxin transport emerged early in streptophyte evolution


PIN-FORMED (PIN) transporters mediate directional, intercellular movement of the phytohormone auxin in land plants. To elucidate the evolutionary origins of this developmentally crucial mechanism, we analysed the single PIN homologue of a simple green alga Klebsormidium flaccidum. KfPIN functions as a plasma membrane-localized auxin exporter in land plants and heterologous models. While its role in algae remains unclear, PIN-driven auxin export is probably an ancient and conserved trait within streptophytes.

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Fig. 1: KfPIN expression in land plant models provokes phenotypes indicative of modulated auxin transport.
Fig. 2: KfPIN auxin transport capacity.
Fig. 3: KfPIN subcellular localization.

Data availability

The underlying data of this study are available from the corresponding author upon request.


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We thank E. D. Cooper and C. F. Delwiche for sharing the K. flaccidum transcriptome sequences before their publication and valuable suggestions; and M. Fílová and R. Granbom for technical assistance. This work was financially supported by the Ministry of Education, Youth and Sports of Czech Republic (MEYS CR) under the projects NPU I, MSM/LO1417 (R.S., S.V. and J.P.), CEITEC 2020, LQ1601 (T.N. and M.Z.), CZ.02.1.01/0.0/0.0/16_019/0000827 (M.K.) and CZ.02.1.01/0.0/0.0/16_013/0001775 (J.P.), the Czech Science Foundation, projects GA18-26981S (J.F. and M.Z.) and GA17-17966Y (M.Z.), German Research Foundation (DFG) project HA3468/6-1 (U.Z.H.), the European Union’s Horizon 2020 programme (ERC grant agreement 742985) (J.F.) and US NSF Award DEB-1036506. T.N., M.Z. and E.M. acknowledge the CELLIM Core Facility of CEITEC and R.S., P.S. and J.P. acknowledge the imaging facility of IEB CAS, both supported by the Czech-BioImaging large RI project (LM2015062 funded by MEYS CR). T.N., M.Z. and E.M. acknowledge the Plant Sciences Core Facility of CEITEC MU. K.L. and M.K. acknowledge the Knut and Alice Wallenberg Foundation, the Swedish Governmental Agency for Innovation Systems (VINNOVA), the Swedish Research Council (VR) and the Swedish Metabolomics Centre.

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Authors and Affiliations



J.F., J.P. and R.S. conceptualized the project. R.S., E.M. and T.V. performed and analysed most experiments. T.V. cloned most constructs. Y.Z. cloned the PIN2::KfPIN:GFP construct and produced and analysed the Arabidopsis line. D.P.J. and U.Z.H. provided data on Xenopus oocytes. M.Z. designed the anti-KfPIN-specific antibody. M.K. analysed auxin content in biomass and media. S.V. performed statistical analysis. M.Z., T.N., K.M., K.L., P.S., J.F. and J.P. oversaw the experiments. R.S. wrote the manuscript and J.F. and J.P. oversaw the writing.

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Correspondence to Jiří Friml.

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The authors declare no competing interests.

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Peer review information Nature Plants thanks Bert van Duijn and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary Figs. 1–5, Supplementary Table 1, Supplementary Methods and Supplementary Methods References.

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Skokan, R., Medvecká, E., Viaene, T. et al. PIN-driven auxin transport emerged early in streptophyte evolution. Nat. Plants 5, 1114–1119 (2019).

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