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ABSTRACT Directional intercellular transport of the phytohormone auxin mediated by PIN-FORMED (PIN) efflux carriers has essential roles in both coordinating patterning processes and

integrating multiple external cues by rapidly redirecting auxin fluxes. PIN activity is therefore regulated by multiple internal and external cues, for which the underlying molecular

mechanisms are not fully elucidated. Here, we demonstrate that 3′-PHOSPHOINOSITIDE-DEPENDENT PROTEIN KINASE1 (PDK1), which is conserved in plants and mammals, functions as a molecular hub

that perceives upstream lipid signalling and modulates downstream substrate activity through phosphorylation. Using genetic analysis, we show that the loss-of-function _Arabidopsis pdk1.1_ 

_pdk1.2_ mutant exhibits a plethora of abnormalities in organogenesis and growth due to defective polar auxin transport. Further cellular and biochemical analyses reveal that PDK1

phosphorylates D6 protein kinase, a well-known upstream activator of PIN proteins. We uncover a lipid-dependent phosphorylation cascade that connects membrane-composition-based cellular

signalling with plant growth and patterning by regulating morphogenetic auxin fluxes. Access through your institution Buy or subscribe This is a preview of subscription content, access via

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institutional subscriptions * Read our FAQs * Contact customer support SIMILAR CONTENT BEING VIEWED BY OTHERS A PHOSPHOINOSITIDE HUB CONNECTS CLE PEPTIDE SIGNALING AND POLAR AUXIN EFFLUX

REGULATION Article Open access 26 January 2023 WAVY GROWTH ARABIDOPSIS E3 UBIQUITIN LIGASES AFFECT APICAL PIN SORTING DECISIONS Article Open access 01 September 2022 TMK-BASED CELL-SURFACE

AUXIN SIGNALLING ACTIVATES CELL-WALL ACIDIFICATION Article Open access 27 October 2021 DATA AVAILABILITY Source data for Figs. 1–6, and Extended Figs. 2–4, 7, 9 and 10 are provided with the

paper. Sequencing data from this Article is provided in the _Arabidopsis_ Genome Initiative databases under the following accession numbers: PIN1 (AT1G73590), PIN2 (AT5G57090), PIN3

(AT1G70940), PIN4 (AT2G01420), PIN7 (AT1G23080), PDK1.1 (AT5G04510), PDK1.2 (AT3G10540), D6PK (AT5G55910), D6PKL1 (AT4G26610), D6PKL2 (AT5G47750), D6PKL3 (AT3G27580), PID (AT2G34650), WAG1

(AT1G53700) and WAG2 (AT3G14370). All data necessary to evaluate the conclusions in the paper or the Supplementary Information are available from the corresponding authors on request. CHANGE

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ACKNOWLEDGEMENTS We thank C. Schwechheimer and B. Scheres for sharing published materials; M. Glanc for providing pET28a-PIN2/3 plasmids; X. Gao for help with SEM imaging, L. Rodriguez for

advice on co-IP; staff at the bioimaging and life science facilities of IST Austria for continuous service and assistance; and the Nottingham _Arabidopsis_ Stock Centre (NASC) and the

_Arabidopsis_ Biological Resource Centre (ABRC) for providing T-DNA insertional mutants. J.P. acknowledges the support from imaging facility of IEB CAS. The research leading to these results

has received funding from Chinese Ten-Thousand Talent Program (to H.-W.X.) and the European Union’s Horizon2020 program (ERC grant agreement no. 742985, to J.F.). S.T. was funded by a

European Molecular Biology Organization (EMBO) long-term postdoctoral fellowship (ALTF 723–2015). X.Z. was supported by a PhD scholarship from China Scholarship Council. AUTHOR INFORMATION

AUTHORS AND AFFILIATIONS * Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria Shutang Tan, Xixi Zhang, Gergely Molnár & Jiří Friml * Department of Applied

Genetics and Cell Biology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria Xixi Zhang & Gergely Molnár * National Key Laboratory of Plant Molecular Genetics,

CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China Wei Kong, Xiao-Li Yang & Hong-Wei

Xue * Institute of Experimental Botany, The Czech Academy of Sciences, Prague, Czech Republic Zuzana Vondráková, Roberta Filepová & Jan Petrášek * Joint Center for Single Cell Biology,

School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China Hong-Wei Xue Authors * Shutang Tan View author publications You can also search for this author inPubMed 

Google Scholar * Xixi Zhang View author publications You can also search for this author inPubMed Google Scholar * Wei Kong View author publications You can also search for this author

inPubMed Google Scholar * Xiao-Li Yang View author publications You can also search for this author inPubMed Google Scholar * Gergely Molnár View author publications You can also search for

this author inPubMed Google Scholar * Zuzana Vondráková View author publications You can also search for this author inPubMed Google Scholar * Roberta Filepová View author publications You

can also search for this author inPubMed Google Scholar * Jan Petrášek View author publications You can also search for this author inPubMed Google Scholar * Jiří Friml View author

publications You can also search for this author inPubMed Google Scholar * Hong-Wei Xue View author publications You can also search for this author inPubMed Google Scholar CONTRIBUTIONS

S.T., J.F. and H.-W.X. designed experiments. S.T., X.Z., W.K. and X.-L.Y. performed experiments. G.M. provided [32P]ATP and helped with kinase assays. J.P., Z.V. and R.F. performed

experiments in BY-2 cells. S.T., J.F. and H.-W.X. analysed and interpreted the data. S.T., J.F. and H.-W.X. wrote the manuscript with input from other co-authors, and all of the authors read

and revised the manuscript. CORRESPONDING AUTHORS Correspondence to Jiří Friml or Hong-Wei Xue. ETHICS DECLARATIONS COMPETING INTERESTS The authors declare no competing interests.

ADDITIONAL INFORMATION PUBLISHER’S NOTE Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. EXTENDED DATA EXTENDED DATA

FIG. 1 EXPRESSION PATTERN OF _PDK1.1_ AND _PDK1.2_. GUS staining of _pPDK1.1::GUS_ and _pPDK1.2::GUS_ lines indicated that _PDK1.1_ and _PDK1.2_ were expressed in the vascular tissues in

both roots and shoots at various developmental stages, including young seedlings (A, F; 7 days), root stele (B, G; 7 days), columella cells (C, H, only with expression detected for _PDK1.1_;

7 days), lateral root primordia (D, I; 12 days), and dark-grown seedlings (E, J; 4 days). Representative images of three independent homozygous lines were shown. Scale bars, 1 mm. EXTENDED

DATA FIG. 2 IDENTIFICATION OF _ARABIDOPSIS PDK1.1_ AND _PDK1.2_ T-DNA INSERTIONAL MUTANTS. A, Schematic representation of _PDK1.1_ and _PDK1.2_ genes and positions of T-DNA insertions for

_pdk1.1_ and _pdk1.2_. Introns, exons, and non-coding regions are indicated by lines, black, or blank boxes respectively. Positions of primers are indicated. B, Identification of homozygous

_pdk1.1_ and _pdk1.2_ mutants. Genomic DNA of _pdk1.1_ and _pdk1.2_ mutants was used as templates for PCR amplification. Homozygous lines have a single amplified DNA fragment when using

LBa1/pdk1.1-RP or LBa1/pdk1.2-RP primers. n = 5 biologically independent experiments, with similar results obtained. C, qRT-PCR analysis confirmed the deficient expression of _PDK1.1_ and

_PDK1.2_ genes in _pdk1.1_ and _pdk1.2_ mutants, respectively. Total RNA of 7-day-old WT, _pdk1.1_ and _pdk1.2_ seedlings was extracted, reversely transcribed, and then used for analysis.

_ACTIN7_ was amplified and used as an internal reference to normalize the expression of _PDK1.1_ and _PDK1.2_, and the mean value in Col-0 was set as “1”. The experiments were biologically

repeated for 3 times. Dots represent individual samples, and lines indicate mean ± s.d.. _P_ values were calculated by a Welch’s two-tailed _t_-test. Source Data EXTENDED DATA FIG. 3

DEFICIENCY OF _PDK1.1_ AND _PDK1.2_ IMPAIRED THE HYPOCOTYL GRAVITROPISM UNDER DARK AND PHOTOTROPISM TOWARDS DIRECTIONAL LIGHT. A, Deficiency of _PDK1.1_ and _PDK1.2_ promoted the radial

growth in the root columella cell region. Transverse view of the root columella cells by CLSM. Left, a schematic image to show the positon for the transverse view; middle, Col-0; right,

_pdk1.1 pdk1.2_. Scale bars, 20 µm. n = 3 biologically independent experiments, with similar results obtained. B, Deficiency of _PDK1.1_ and _PDK1.2_ gave rise to more columns, but not

layers of, root columella cells. Quantification is based on CLSM images of PI-stained roots. Layer numbers were counted for both undifferentiated and differentiated columella cells. Dots

represent individual plants, and lines indicate mean ± s.d.. n = 18, 26, 18, and 26, from left to right, respectively. _P_ values were calculated by a Welch’s two-tailed _t_-test. C–E,

Deficiency of _PDK1.1_ and _PDK1.2_ impaired root and shoot gravitropic response in the dark. Etiolated seedlings of Col-0, _pdk1.1_, _pdk1.2_, and _pdk1.1 pdk1.2_ were grown under dark for

90 h and a representative photo was shown (C). Scale bar, 5 mm. n = 5 biologically independent experiments, with similar results obtained (C). (D), Root tip angles are shown as polar bar

charts. n = 61, 62, 69, and 71, respectively. (E), Hypocotyl angles are shown as polar bar charts. n = 51, 50, 59, and 68, respectively. F–G, _pdk1.1 pdk1.2_ showed defects in phototropism.

Seedlings of Col-0, _pdk1.1_, _pdk1.2_, and _pdk1.1 pdk1.2_ were grown under dark for 90 h, exposed to white light for 24 h, and were then subjected to directional white light in a box

covered with aluminium foil from the other sides. A representative photo is shown (f). Scale bar, 5 mm. n = 3 biologically independent experiments, with similar results obtained (F). (G),

hypocotyl angles are shown by polar bar charts. n = 56, 62, 67, and 62, respectively. _P_ values were calculated by a Welch’s two-tailed _t_-test, and also by a further F-test to indicate

differences of variances (D, E, and G). Source Data EXTENDED DATA FIG. 4 DEFICIENCY OF _PDK1.1_ AND _PDK1.2_ IMPAIRED THE NORMAL DEVELOPMENT OF THE APICAL HOOK AND HIGH TEMPERATURE-INDUCED

HYPOCOTYL ELONGATION. A, B, Observation (A, scale bar, 5 mm) and quantification (B) showed that etiolated seedlings (90 h) of _pdk1.1 pdk1.2_ exhibited less tight apical hooks. n = 5

biologically independent experiments, with similar results obtained (A). n = 14, 18, 12 and 17 seedlings for Col-0, _pdk1.1_, _pdk1.2_, and _pdk1.1 pdk1.2_ respectively (B). C, Etiolated

seedlings of _pdk1.1 pdk1.2_ exhibited comparably long hypocotyls to Col-0. Seedlings were grown under dark for 90 h. n = 20, 21, 20 and 17 seedlings for Col-0, _pdk1.1_, _pdk1.2_, and

_pdk1.1 pdk1.2_ respectively. D, Etiolated seedlings of _pdk1.1 pdk1.2_ did not form exaggerated apical hooks in the presence of ACC. Seedlings of Col-0, _pdk1.1_, _pdk1.2_, and _pdk1.1

pdk1.2_ were grown under dark for 90 h in the absence or presence of ACC (10 µM). Scale bars, 500 µm. n = 3 biologically independent experiments, with similar results obtained. E–F, _pdk1.1

pdk1.2_ showed defects in high temperature-induced hypocotyl elongation. Seedlings of Col-0, _pdk1.1_, _pdk1.2_ and _pdk1.1 pdk1.2_ were grown under light at 22 °C (n = 16, 20, 18 and 22

respectively) or 29 °C (n = 20, 21, 17 and 18) for 5 days, and hypocotyl elongation was observed (E, scale bar, 1 cm) and quantified (E). Hypocotyl length was measured by the Image J program

and shown as mean ± s.d. (left) or relative length by setting the hypocotyl length of Col-0 and _pdk1.1 pdk1.2_ at 22 °C as “1”, respectively (right). Dots represent individual plants, and

lines indicate mean ± s.d.. Different letters represent significant difference, _P <_ 0.05, by one-way ANOVA with a Tukey multiple comparison test, and _P_ values are shown for each

genotype compared with Col-0 (B, C, and F). Source Data EXTENDED DATA FIG. 5 LOSS OF FUNCTION OF _PDK1.1_ AND _PDK1.2_ IMPAIRED AUXIN DISTRIBUTION. Observation of the auxin responsive

reporter DR5rev::GFP by CLSM indicated a dramatic decrease of the auxin maxima in _pdk1.1 pdk1.2_ (E–H) compared with Col-0 (A–D). Fused cotyledon exhibiting two sites of auxin maxima in

light-grown 7-day-old seedlings of _pdk1.1 pdk1.2_ (E) compared with one of Col-0 (A); roots of light-grown 10-day-old seedlings (B and F); apical hooks of 10 µM ACC treated 4-day-old

etiolated seedlings (C and G); roots of 10 µM ACC treated 4-day-old etiolated seedlings (D and H). Scale bars, 200 µm. n = 3 biologically independent experiments, with similar results

obtained. EXTENDED DATA FIG. 6 DEFICIENCY OF _PDK1.1_ AND _PDK1.2_ DID NOT AFFECT THE POLARITY OF PIN PROTEINS. A, Deficiency of _PDK1.1_ and _PDK1.2_ did not change the polarity of

PIN1-YFP. Four-day-old seedlings of _pPIN1::PIN1-YFP_ in Col-0 and _pPIN1::PIN1-YF_P in _pdk1.1 pdk1.2_ were imaged by CLSM. Scale bars, 20 µm. n = 2 biologically independent experiments,

with similar results obtained (A-G). B, Deficiency of _PDK1.1_ and _PDK1.2_ did not change the polarity of PIN2-GFP. Four-day-old seedlings of _pPIN2::PIN2-GFP_ in Col-0 and

_pPIN2::PIN2-GFP_ in _pdk1.1 pdk1.2_ were imaged by CLSM. Scale bars, 20 µm. C–F, Deficiency of _PDK1.1_ and _PDK1.2_ did not change the polarity of PIN3-GFP. Four-day-old seedlings of

_pPIN3::PIN3-GFP_ in Col-0 and _pPIN3::PIN3-GFP_ in _pdk1.1 pdk1.2_ were imaged by CLSM. (C) subcellular localisation of PIN3-GFP; (D) an amplified view of PIN3-GFP in the root stele; (E) a

close view of PIN3-GFP in root columella cells; (F) a 3D-projection of PIN3-GFP localisation in root columella cells. The “Green Fire Blue” LUT was used for photo visualization based on

fluorescence intensity by Fiji. Scale bars, 20 µm. G, A transverse view of the root columella cells revealed the overproliferation, with an enlarged region expressing PIN3-GFP. Four-day-old

seedlings of _pPIN3::PIN3-GFP_ in Col-0 and _pPIN3::PIN3-GFP_ in _pdk1.1 pdk1.2_ were stained with PI, and imaged by CLSM, at the position as marked in the left image. Scale bars, 20 µm.

EXTENDED DATA FIG. 7 ANALYSIS OF _PDK1_ TRANSGENIC LINES. A, Expression of _PDK1.1_ or _PDK1.2_ (_p35S::Venus-PDK1.1, p35S::Venus-PDK1.2, p35S::mCherry-PDK1.1_ and _p35S::mCherry-PDK1.2_)

rescued the growth defects of _pdk1.1 pdk1.2_. Adult plants (25-day-old) were observed and representative photos were shown. Scale bar, 2 cm. B, Western blot analysis verified the PDK1.1 or

PDK1.2 expression (_p35S::Venus-PDK1.1_ and _p35S::Venus-PDK1.2_) in _pdk1.1 pdk1.2_, respectively. Seven-day-old T3 homozygous seedlings were used for protein extraction and subjected to

analysis. Upper panel, anti-GFP (1:2000); lower panel, Ponceau staining. C, Western blot verified the PDK1.1 or PDK1.2 expression (_p35S::mCherry-PDK1.1_ and _p35S::mCherry-PDK1.2_) in

_pdk1.1 pdk1.2_, respectively. Seven-day-old T3 homozygous seedlings were used for protein extraction and subjected to analysis. Upper panel, anti-RFP (1:2000); lower panel, Ponceau

staining. D–E, mCherry-fused PDK1.1 (D) and PDK1.2 (E) localised to both cytoplasm and the basal side of PM. Four-day-old seedlings of _p35S::mCherry-PDK1.1_ and _p35S::mCherry-PDK1.2_ were

imaged by CLSM. Open arrowheads indicated the basal polar localisation. Scale bar, 10 µm. F–I, Subcellular localisation of Venus-fused PDK1.1N (F, cytoplasm), Venus-fused PDK1.1C (G, both

cytoplasm and nucleus), Venus-fused PDK1.2N (h, cytoplasm), and Venus-fused PDK1.2C (i, both cytoplasm and nucleus). Four-day-old seedlings expressing corresponding fusion proteins were

imaged by CLSM. Scale bar, 10 µm. n = 4, 2, 3, and 3 biologically independent experiments for (A), (B), (C), and (D) respectively, with similar results obtained. Source Data EXTENDED DATA

FIG. 8 FUNCTIONAL _PPDK1.1::VENUS-PDK1.1_ LOCALISED AT BOTH CYTOPLASM AND THE BASAL SIDE OF PM. A, _pPDK1.1::Venus-PDK1.1_ rescued the growth defects of _pdk1.1 pdk1.2_. 25-day-old adult

plants were observed and representative photos are shown. Scale bar, 2 cm. B, _pPDK1.1::Venus-PDK1.1_ rescued the lateral root defects of _pdk1.1 pdk1.2_. 10-day-old seedlings were observed

and representative photos are shown. Scale bar, 2 cm. C, _pPDK1.1::Venus-PDK1.1_ rescued the defects of _pdk1.1 pdk1.2_ in the hypocotyl gravitropic response. 4-day-old etiolated seedlings

were observed and representative photos are shown. Scale bar, 2 cm. D, Venus-fused PDK1.1 localised to both cytoplasm and PM, especially with a predominant presence at the basal side of PM.

Four-day-old seedlings of _pPDK1.1::Venus-PDK1.1_ were imaged by CLSM. Open arrowheads indicate the basal polar localisation. The “Green Fire Blue” LUT was used for photo visualization based

on fluorescence intensity by Fiji. Scale bar, 20 µm. E, Venus-PDK1.1 localized to cytoplasm (upper image) in interphase tobacco BY-2 cells, and the association with PM was obvious only

during cytokinesis (arrow in lower image). An _XVE>>Venus-PDK1.1_ line was induced for 48 h with 1 μM β-estradiol and were then imaged by spinning disk confocal microscope. Scale bar,

10 μm. n = 3, 3, 2, 3, and 2 biologically independent experiments for (A), (B), (C), (D), and (E) respectively, with similar results obtained. EXTENDED DATA FIG. 9 MCHERRY-D6PKS CO-LOCALISED

WITH VENUS-PDK1.1 AT THE BASAL SIDE OF PM. A, mCherry-fused D6PKs localised to the basal side of PM. Four-day-old seedlings of _p35S::mCherry-D6PK/D6PKLs_ (short as _D0 to D3_) were imaged

by CLSM. The “mpl-inferno” LUT was used for photo visualization based on fluorescence intensity by Fiji. Scale bars, 10 µm. B, Western blot verified the mCherry-D0~D3 protein level

(_35S::mCherry-D0~D3_) in Col-0, respectively. Seven-day-old T3 homozygous seedlings were used for protein extraction and subjected to Western blot analysis. Upper panel, anti-RFP (1:1000),

short exposure (0.5 sec); medium panel, anti-RFP (1:1000), long exposure (5 sec, for low expression of mCherry-D3); lower panel, Ponceau staining. C, Venus-PDK1.1 co-localised with

mCherry-D6PKL2 and mCherry-D6PKL3 at the basal side of PM. Four-day-old seedlings of _p35S::mCherry-_D6PKL2_/ p35S::Venus-PDK1.1_ and _p35S::mCherry-_D6PKL3_/ p35S::Venus-PDK1.1_ were imaged

by CLSM. Scale bar, 10 µm. D, _In vitro_ kinase assay with [32P]-ATP revealed that GST-PDK1.2-conducted phosphorylation of D6PK facilitates its activity towards PIN-HL phosphorylation.

Upper panel, autoradiography; lower panel, CBB staining. E, _In vitro_ kinase assay with [32P]-ATP revealed that GST-PDK1.2-conducted full phosphorylation and activation of D6PK, towards

His-PIN1-HL phosphorylation, required the phosphorylation at S345 for D6PK. Upper panel, autoradiography of 32P; lower panel, CBB staining. n = 3, 2, 2, 3, and 3 biologically independent

experiments for (A), (B), (C), (D), and (E) respectively, with similar results obtained. Source Data EXTENDED DATA FIG. 10 OVEREXPRESSION OF _VENUS-D6PK__S345D_ RESCUED THE DEFECTS OF

LATERAL ROOT FORMATION AND HYPOCOTYL GRAVITROPISM IN _PDK1.1 PDK1.2_. A, B, _35S::Venus-D6PK__S345D_ (L3 as a representative line) rescued the lateral root defects of _pdk1.1 pdk1.2_.

Nine-day-old seedlings were observed. n = 3 biologically independent experiments, with similar results obtained. A representative photo is shown in (A, scale bar, 2 cm), and the lateral root

number was quantified (b). Dots represent individual plants, and lines indicate mean ± s.d.. n = 15, 15, 14 and 14 individual seedlings for Col-0, _pdk1.1 pdk1.2_, _35S::Venus-D6PK__S345D_

in _pdk1.1 pdk1.2_ (L3), and _35S::Venus-D6PK__S345D_ in _pdk1.1 pdk1.2_ (L5), respectively. Different letters represent significant difference, _P <_ 0.05, by one-way ANOVA with a Tukey

multiple comparison test, and _P_ values are shown for each genotype compared with Col-0. C, The subcellular localisations of Venus-D6PK, Venus-D6PKS345A, and Venus-D6PKS345D exhibit

difference in PM targeting, but not show difference in the basal polarity. Four-day-old seedlings of _p35S::Venus-D6PK_, _p35S::Venus-D6PK__S345A_, and _p35S::Venus-D6PK__S345D_, in Col-0

and _pdk1.1 pdk1.2_ respectively, were imaged by CLSM. The “Green Fire Blue” LUT was used for photo visualization based on fluorescence intensity by Fiji. Representative photos of at least

three independent transgenic lines were shown. Scale bars, 10 µm. n = 2 biologically independent experiments, with similar results obtained. Source Data SUPPLEMENTARY INFORMATION

SUPPLEMENTARY INFORMATION Supplementary Figs. 1–9, Tables 1–7 and references for the Supplementary Information. REPORTING SUMMARY SOURCE DATA SOURCE DATA FIG. 1 Statistical source data.

SOURCE DATA FIG. 2 Statistical source data. SOURCE DATA FIG. 3 Unprocessed western blots and/or gels. SOURCE DATA FIG. 4 Statistical source data. SOURCE DATA FIG. 4 Unprocessed western blots

and/or gels. SOURCE DATA FIG. 5 Statistical source data. SOURCE DATA FIG. 5 Unprocessed western blots and/or gels. SOURCE DATA FIG. 6 Statistical source data. SOURCE DATA FIG. 6 Unprocessed

western blots and/or gels. SOURCE DATA EXTENDED DATA FIG. 2 Statistical source data. SOURCE DATA EXTENDED DATA FIG. 2 Unprocessed western blots and/or gels. SOURCE DATA EXTENDED DATA FIG. 3

Statistical source data. SOURCE DATA EXTENDED DATA FIG. 4 Statistical source data. SOURCE DATA EXTENDED DATA FIG. 7 Unprocessed western blots and/or gels. SOURCE DATA EXTENDED DATA FIG. 9

Statistical source data. SOURCE DATA EXTENDED DATA FIG. 9 Unprocessed western blots and/or gels. SOURCE DATA EXTENDED DATA FIG. 10 Statistical source data. RIGHTS AND PERMISSIONS Reprints

and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Tan, S., Zhang, X., Kong, W. _et al._ The lipid code-dependent phosphoswitch PDK1–D6PK activates PIN-mediated auxin efflux in

_Arabidopsis_. _Nat. Plants_ 6, 556–569 (2020). https://doi.org/10.1038/s41477-020-0648-9 Download citation * Received: 31 August 2019 * Accepted: 25 March 2020 * Published: 11 May 2020 *

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