@article{8931, abstract = {Auxin is a major plant growth regulator, but current models on auxin perception and signaling cannot explain the whole plethora of auxin effects, in particular those associated with rapid responses. A possible candidate for a component of additional auxin perception mechanisms is the AUXIN BINDING PROTEIN 1 (ABP1), whose function in planta remains unclear. Here we combined expression analysis with gain- and loss-of-function approaches to analyze the role of ABP1 in plant development. ABP1 shows a broad expression largely overlapping with, but not regulated by, transcriptional auxin response activity. Furthermore, ABP1 activity is not essential for the transcriptional auxin signaling. Genetic in planta analysis revealed that abp1 loss-of-function mutants show largely normal development with minor defects in bolting. On the other hand, ABP1 gain-of-function alleles show a broad range of growth and developmental defects, including root and hypocotyl growth and bending, lateral root and leaf development, bolting, as well as response to heat stress. At the cellular level, ABP1 gain-of-function leads to impaired auxin effect on PIN polar distribution and affects BFA-sensitive PIN intracellular aggregation. The gain-of-function analysis suggests a broad, but still mechanistically unclear involvement of ABP1 in plant development, possibly masked in abp1 loss-of-function mutants by a functional redundancy.}, author = {Gelová, Zuzana and Gallei, Michelle C and Pernisová, Markéta and Brunoud, Géraldine and Zhang, Xixi and Glanc, Matous and Li, Lanxin and Michalko, Jaroslav and Pavlovicova, Zlata and Verstraeten, Inge and Han, Huibin and Hajny, Jakub and Hauschild, Robert and Čovanová, Milada and Zwiewka, Marta and Hörmayer, Lukas and Fendrych, Matyas and Xu, Tongda and Vernoux, Teva and Friml, Jiří}, issn = {0168-9452}, journal = {Plant Science}, keywords = {Agronomy and Crop Science, Plant Science, Genetics, General Medicine}, publisher = {Elsevier}, title = {{Developmental roles of auxin binding protein 1 in Arabidopsis thaliana}}, doi = {10.1016/j.plantsci.2020.110750}, volume = {303}, year = {2021}, } @article{9287, abstract = {The phytohormone auxin and its directional transport through tissues are intensively studied. However, a mechanistic understanding of auxin-mediated feedback on endocytosis and polar distribution of PIN auxin transporters remains limited due to contradictory observations and interpretations. Here, we used state-of-the-art methods to reexamine the auxin effects on PIN endocytic trafficking. We used high auxin concentrations or longer treatments versus lower concentrations and shorter treatments of natural (IAA) and synthetic (NAA) auxins to distinguish between specific and nonspecific effects. Longer treatments of both auxins interfere with Brefeldin A-mediated intracellular PIN2 accumulation and also with general aggregation of endomembrane compartments. NAA treatment decreased the internalization of the endocytic tracer dye, FM4-64; however, NAA treatment also affected the number, distribution, and compartment identity of the early endosome/trans-Golgi network (EE/TGN), rendering the FM4-64 endocytic assays at high NAA concentrations unreliable. To circumvent these nonspecific effects of NAA and IAA affecting the endomembrane system, we opted for alternative approaches visualizing the endocytic events directly at the plasma membrane (PM). Using Total Internal Reflection Fluorescence (TIRF) microscopy, we saw no significant effects of IAA or NAA treatments on the incidence and dynamics of clathrin foci, implying that these treatments do not affect the overall endocytosis rate. However, both NAA and IAA at low concentrations rapidly and specifically promoted endocytosis of photo-converted PIN2 from the PM. These analyses identify a specific effect of NAA and IAA on PIN2 endocytosis, thus contributing to its polarity maintenance and furthermore illustrate that high auxin levels have nonspecific effects on trafficking and endomembrane compartments. }, author = {Narasimhan, Madhumitha and Gallei, Michelle C and Tan, Shutang and Johnson, Alexander J and Verstraeten, Inge and Li, Lanxin and Rodriguez Solovey, Lesia and Han, Huibin and Himschoot, E and Wang, R and Vanneste, S and Sánchez-Simarro, J and Aniento, F and Adamowski, Maciek and Friml, Jiří}, issn = {1532-2548}, journal = {Plant Physiology}, number = {2}, pages = {1122–1142}, publisher = {Oxford University Press}, title = {{Systematic analysis of specific and nonspecific auxin effects on endocytosis and trafficking}}, doi = {10.1093/plphys/kiab134}, volume = {186}, year = {2021}, } @phdthesis{10083, abstract = {Plant motions occur across a wide spectrum of timescales, ranging from seed dispersal through bursting (milliseconds) and stomatal opening (minutes) to long-term adaptation of gross architecture. Relatively fast motions include water-driven growth as exemplified by root cell expansion under abiotic/biotic stresses or during gravitropism. A showcase is a root growth inhibition in 30 seconds triggered by the phytohormone auxin. However, the cellular and molecular mechanisms are still largely unknown. This thesis covers the studies about this topic as follows. By taking advantage of microfluidics combined with live imaging, pharmaceutical tools, and transgenic lines, we examined the kinetics of and causal relationship among various auxininduced rapid cellular changes in root growth, apoplastic pH, cytosolic Ca2+, cortical microtubule (CMT) orientation, and vacuolar morphology. We revealed that CMT reorientation and vacuolar constriction are the consequence of growth itself instead of responding directly to auxin. In contrast, auxin induces apoplast alkalinization to rapidly inhibit root growth in 30 seconds. This auxin-triggered apoplast alkalinization results from rapid H+- influx that is contributed by Ca2+ inward channel CYCLIC NUCLEOTIDE-GATED CHANNEL 14 (CNGC14)-dependent Ca2+ signaling. To dissect which auxin signaling mediates the rapid apoplast alkalinization, we combined microfluidics and genetic engineering to verify that TIR1/AFB receptors conduct a non-transcriptional regulation on Ca2+ and H+ -influx. This non-canonical pathway is mostly mediated by the cytosolic portion of TIR1/AFB. On the other hand, we uncovered, using biochemical and phospho-proteomic analysis, that auxin cell surface signaling component TRANSMEMBRANE KINASE 1 (TMK1) plays a negative role during auxin-trigger apoplast alkalinization and root growth inhibition through directly activating PM H+ -ATPases. Therefore, we discovered that PM H+ -ATPases counteract instead of mediate the auxintriggered rapid H+ -influx, and that TIR1/AFB and TMK1 regulate root growth antagonistically. This opposite effect of TIR1/AFB and TMK1 is consistent during auxin-induced hypocotyl elongation, leading us to explore the relation of two signaling pathways. Assisted with biochemistry and fluorescent imaging, we verified for the first time that TIR1/AFB and TMK1 can interact with each other. The ability of TIR1/AFB binding to membrane lipid provides a basis for the interaction of plasma membrane- and cytosol-localized proteins. Besides, transgenic analysis combined with genetic engineering and biochemistry showed that vi they do function in the same pathway. Particularly, auxin-induced TMK1 increase is TIR1/AFB dependent, suggesting TIR1/AFB regulation on TMK1. Conversely, TMK1 also regulates TIR1/AFB protein levels and thus auxin canonical signaling. To follow the study of rapid growth regulation, we analyzed another rapid growth regulator, signaling peptide RALF1. We showed that RALF1 also triggers a rapid and reversible growth inhibition caused by H + influx, highly resembling but not dependent on auxin. Besides, RALF1 promotes auxin biosynthesis by increasing expression of auxin biosynthesis enzyme YUCCAs and thus induces auxin signaling in ca. 1 hour, contributing to the sustained RALF1-triggered growth inhibition. These studies collectively contribute to understanding rapid regulation on plant cell growth, novel auxin signaling pathway as well as auxin-peptide crosstalk. }, author = {Li, Lanxin}, issn = {2663-337X}, publisher = {Institute of Science and Technology Austria}, title = {{Rapid cell growth regulation in Arabidopsis}}, doi = {10.15479/at:ista:10083}, year = {2021}, } @article{10015, abstract = {Auxin plays a dual role in growth regulation and, depending on the tissue and concentration of the hormone, it can either promote or inhibit division and expansion processes in plants. Recent studies have revealed that, beyond transcriptional reprogramming, alternative auxincontrolled mechanisms regulate root growth. Here, we explored the impact of different concentrations of the synthetic auxin NAA that establish growth-promoting and -repressing conditions on the root tip proteome and phosphoproteome, generating a unique resource. From the phosphoproteome data, we pinpointed (novel) growth regulators, such as the RALF34-THE1 module. Our results, together with previously published studies, suggest that auxin, H+-ATPases, cell wall modifications and cell wall sensing receptor-like kinases are tightly embedded in a pathway regulating cell elongation. Furthermore, our study assigned a novel role to MKK2 as a regulator of primary root growth and a (potential) regulator of auxin biosynthesis and signalling, and suggests the importance of the MKK2 Thr31 phosphorylation site for growth regulation in the Arabidopsis root tip.}, author = {Nikonorova, N and Murphy, E and Fonseca de Lima, CF and Zhu, S and van de Cotte, B and Vu, LD and Balcerowicz, D and Li, Lanxin and Kong, X and De Rop, G and Beeckman, T and Friml, Jiří and Vissenberg, K and Morris, PC and Ding, Z and De Smet, I}, issn = {2073-4409}, journal = {Cells}, keywords = {primary root, (phospho)proteomics, auxin, (receptor) kinase}, publisher = {MDPI}, title = {{The Arabidopsis root tip (phospho)proteomes at growth-promoting versus growth-repressing conditions reveal novel root growth regulators}}, doi = {10.3390/cells10071665}, volume = {10}, year = {2021}, } @unpublished{10095, abstract = {Growth regulation tailors plant development to its environment. A showcase is response to gravity, where shoots bend up and roots down1. This paradox is based on opposite effects of the phytohormone auxin, which promotes cell expansion in shoots, while inhibiting it in roots via a yet unknown cellular mechanism2. Here, by combining microfluidics, live imaging, genetic engineering and phospho-proteomics in Arabidopsis thaliana, we advance our understanding how auxin inhibits root growth. We show that auxin activates two distinct, antagonistically acting signalling pathways that converge on the rapid regulation of the apoplastic pH, a causative growth determinant. Cell surface-based TRANSMEMBRANE KINASE1 (TMK1) interacts with and mediates phosphorylation and activation of plasma membrane H+-ATPases for apoplast acidification, while intracellular canonical auxin signalling promotes net cellular H+-influx, causing apoplast alkalinisation. The simultaneous activation of these two counteracting mechanisms poises the root for a rapid, fine-tuned growth modulation while navigating complex soil environment.}, author = {Li, Lanxin and Verstraeten, Inge and Roosjen, Mark and Takahashi, Koji and Rodriguez Solovey, Lesia and Merrin, Jack and Chen, Jian and Shabala, Lana and Smet, Wouter and Ren, Hong and Vanneste, Steffen and Shabala, Sergey and De Rybel, Bert and Weijers, Dolf and Kinoshita, Toshinori and Gray, William M. and Friml, Jiří}, booktitle = {Research Square}, issn = {2693-5015}, title = {{Cell surface and intracellular auxin signalling for H+-fluxes in root growth}}, doi = {10.21203/rs.3.rs-266395/v3}, year = {2021}, } @article{9010, abstract = {Availability of the essential macronutrient nitrogen in soil plays a critical role in plant growth, development, and impacts agricultural productivity. Plants have evolved different strategies for sensing and responding to heterogeneous nitrogen distribution. Modulation of root system architecture, including primary root growth and branching, is among the most essential plant adaptions to ensure adequate nitrogen acquisition. However, the immediate molecular pathways coordinating the adjustment of root growth in response to distinct nitrogen sources, such as nitrate or ammonium, are poorly understood. Here, we show that growth as manifested by cell division and elongation is synchronized by coordinated auxin flux between two adjacent outer tissue layers of the root. This coordination is achieved by nitrate‐dependent dephosphorylation of the PIN2 auxin efflux carrier at a previously uncharacterized phosphorylation site, leading to subsequent PIN2 lateralization and thereby regulating auxin flow between adjacent tissues. A dynamic computer model based on our experimental data successfully recapitulates experimental observations. Our study provides mechanistic insights broadening our understanding of root growth mechanisms in dynamic environments.}, author = {Ötvös, Krisztina and Marconi, Marco and Vega, Andrea and O’Brien, Jose and Johnson, Alexander J and Abualia, Rashed and Antonielli, Livio and Montesinos López, Juan C and Zhang, Yuzhou and Tan, Shutang and Cuesta, Candela and Artner, Christina and Bouguyon, Eleonore and Gojon, Alain and Friml, Jiří and Gutiérrez, Rodrigo A. and Wabnik, Krzysztof T and Benková, Eva}, issn = {1460-2075}, journal = {EMBO Journal}, number = {3}, publisher = {Embo Press}, title = {{Modulation of plant root growth by nitrogen source-defined regulation of polar auxin transport}}, doi = {10.15252/embj.2020106862}, volume = {40}, year = {2021}, } @article{9887, abstract = {Clathrin-mediated endocytosis is the major route of entry of cargos into cells and thus underpins many physiological processes. During endocytosis, an area of flat membrane is remodeled by proteins to create a spherical vesicle against intracellular forces. The protein machinery which mediates this membrane bending in plants is unknown. However, it is known that plant endocytosis is actin independent, thus indicating that plants utilize a unique mechanism to mediate membrane bending against high-turgor pressure compared to other model systems. Here, we investigate the TPLATE complex, a plant-specific endocytosis protein complex. It has been thought to function as a classical adaptor functioning underneath the clathrin coat. However, by using biochemical and advanced live microscopy approaches, we found that TPLATE is peripherally associated with clathrin-coated vesicles and localizes at the rim of endocytosis events. As this localization is more fitting to the protein machinery involved in membrane bending during endocytosis, we examined cells in which the TPLATE complex was disrupted and found that the clathrin structures present as flat patches. This suggests a requirement of the TPLATE complex for membrane bending during plant clathrin–mediated endocytosis. Next, we used in vitro biophysical assays to confirm that the TPLATE complex possesses protein domains with intrinsic membrane remodeling activity. These results redefine the role of the TPLATE complex and implicate it as a key component of the evolutionarily distinct plant endocytosis mechanism, which mediates endocytic membrane bending against the high-turgor pressure in plant cells.}, author = {Johnson, Alexander J and Dahhan, Dana A and Gnyliukh, Nataliia and Kaufmann, Walter and Zheden, Vanessa and Costanzo, Tommaso and Mahou, Pierre and Hrtyan, Mónika and Wang, Jie and Aguilera Servin, Juan L and van Damme, Daniël and Beaurepaire, Emmanuel and Loose, Martin and Bednarek, Sebastian Y and Friml, Jiří}, issn = {1091-6490}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {51}, publisher = {National Academy of Sciences}, title = {{The TPLATE complex mediates membrane bending during plant clathrin-mediated endocytosis}}, doi = {10.1073/pnas.2113046118}, volume = {118}, year = {2021}, } @article{7582, abstract = {Small RNAs (smRNA, 19–25 nucleotides long), which are transcribed by RNA polymerase II, regulate the expression of genes involved in a multitude of processes in eukaryotes. miRNA biogenesis and the proteins involved in the biogenesis pathway differ across plant and animal lineages. The major proteins constituting the biogenesis pathway, namely, the Dicers (DCL/DCR) and Argonautes (AGOs), have been extensively studied. However, the accessory proteins (DAWDLE (DDL), SERRATE (SE), and TOUGH (TGH)) of the pathway that differs across the two lineages remain largely uncharacterized. We present the first detailed report on the molecular evolution and divergence of these proteins across eukaryotes. Although DDL is present in eukaryotes and prokaryotes, SE and TGH appear to be specific to eukaryotes. The addition/deletion of specific domains and/or domain-specific sequence divergence in the three proteins points to the observed functional divergence of these proteins across the two lineages, which correlates with the differences in miRNA length across the two lineages. Our data enhance the current understanding of the structure–function relationship of these proteins and reveals previous unexplored crucial residues in the three proteins that can be used as a basis for further functional characterization. The data presented here on the number of miRNAs in crown eukaryotic lineages are consistent with the notion of the expansion of the number of miRNA-coding genes in animal and plant lineages correlating with organismal complexity. Whether this difference in functionally correlates with the diversification (or presence/absence) of the three proteins studied here or the miRNA signaling in the plant and animal lineages is unclear. Based on our results of the three proteins studied here and previously available data concerning the evolution of miRNA genes in the plant and animal lineages, we believe that miRNAs probably evolved once in the ancestor to crown eukaryotes and have diversified independently in the eukaryotes.}, author = {Moturu, Taraka Ramji and Sinha, Sansrity and Salava, Hymavathi and Thula, Sravankumar and Nodzyński, Tomasz and Vařeková, Radka Svobodová and Friml, Jiří and Simon, Sibu}, issn = {2223-7747}, journal = {Plants}, number = {3}, publisher = {MDPI}, title = {{Molecular evolution and diversification of proteins involved in miRNA maturation pathway}}, doi = {10.3390/plants9030299}, volume = {9}, year = {2020}, } @article{7600, abstract = {Directional intercellular transport of the phytohormone auxin mediated by PIN FORMED (PIN) efflux carriers plays essential roles in both coordinating patterning processes and integrating multiple external cues by rapidly redirecting auxin fluxes. Multilevel regulations of PIN activity under internal and external cues are complicated; however, the underlying molecular mechanism remains elusive. Here we demonstrate that 3’-Phosphoinositide-Dependent Protein Kinase1 (PDK1), which is conserved in plants and mammals, functions as a molecular hub integrating the upstream lipid signalling and the downstream substrate activity through phosphorylation. Genetic analysis uncovers that loss-of-function Arabidopsis mutant pdk1.1 pdk1.2 exhibits a plethora of abnormalities in organogenesis and growth, due to the defective PIN-dependent auxin transport. Further cellular and biochemical analyses reveal that PDK1 phosphorylates D6 Protein Kinase to facilitate its activity towards PIN proteins. Our studies establish a lipid-dependent phosphorylation cascade connecting membrane composition-based cellular signalling with plant growth and patterning by regulating morphogenetic auxin fluxes.}, author = {Tan, Shutang and Zhang, Xixi and Kong, Wei and Yang, Xiao-Li and Molnar, Gergely and Vondráková, Zuzana and Filepová, Roberta and Petrášek, Jan and Friml, Jiří and Xue, Hong-Wei}, issn = {2055-0278}, journal = {Nature Plants}, pages = {556--569}, publisher = {Springer Nature}, title = {{The lipid code-dependent phosphoswitch PDK1–D6PK activates PIN-mediated auxin efflux in Arabidopsis}}, doi = {10.1038/s41477-020-0648-9}, volume = {6}, year = {2020}, } @article{7619, abstract = {Cell polarity is a fundamental feature of all multicellular organisms. In plants, prominent cell polarity markers are PIN auxin transporters crucial for plant development. To identify novel components involved in cell polarity establishment and maintenance, we carried out a forward genetic screening with PIN2:PIN1-HA;pin2 Arabidopsis plants, which ectopically express predominantly basally localized PIN1 in the root epidermal cells leading to agravitropic root growth. From the screen, we identified the regulator of PIN polarity 12 (repp12) mutation, which restored gravitropic root growth and caused PIN1-HA polarity switch from basal to apical side of root epidermal cells. Complementation experiments established the repp12 causative mutation as an amino acid substitution in Aminophospholipid ATPase3 (ALA3), a phospholipid flippase with predicted function in vesicle formation. ala3 T-DNA mutants show defects in many auxin-regulated processes, in asymmetric auxin distribution and in PIN trafficking. Analysis of quintuple and sextuple mutants confirmed a crucial role of ALA proteins in regulating plant development and in PIN trafficking and polarity. Genetic and physical interaction studies revealed that ALA3 functions together with GNOM and BIG3 ARF GEFs. Taken together, our results identified ALA3 flippase as an important interactor and regulator of ARF GEF functioning in PIN polarity, trafficking and auxin-mediated development.}, author = {Zhang, Xixi and Adamowski, Maciek and Marhavá, Petra and Tan, Shutang and Zhang, Yuzhou and Rodriguez Solovey, Lesia and Zwiewka, Marta and Pukyšová, Vendula and Sánchez, Adrià Sans and Raxwal, Vivek Kumar and Hardtke, Christian S. and Nodzynski, Tomasz and Friml, Jiří}, issn = {1532-298X}, journal = {The Plant Cell}, number = {5}, pages = {1644--1664}, publisher = {American Society of Plant Biologists}, title = {{Arabidopsis flippases cooperate with ARF GTPase exchange factors to regulate the trafficking and polarity of PIN auxin transporters}}, doi = {10.1105/tpc.19.00869}, volume = {32}, year = {2020}, } @article{7646, abstract = {In plant cells, environmental stressors promote changes in connectivity between the cortical ER and the PM. Although this process is tightly regulated in space and time, the molecular signals and structural components mediating these changes in inter-organelle communication are only starting to be characterized. In this report, we confirm the presence of a putative tethering complex containing the synaptotagmins 1 and 5 (SYT1 and SYT5) and the Ca2+ and lipid binding protein 1 (CLB1/SYT7). This complex is enriched at ER-PM contact sites (EPCS), have slow responses to changes in extracellular Ca2+, and display severe cytoskeleton-dependent rearrangements in response to the trivalent lanthanum (La3+) and gadolinium (Gd3+) rare earth elements (REEs). Although REEs are generally used as non-selective cation channel blockers at the PM, here we show that the slow internalization of REEs into the cytosol underlies the activation of the Ca2+/Calmodulin intracellular signaling, the accumulation of phosphatidylinositol-4-phosphate (PI4P) at the PM, and the cytoskeleton-dependent rearrangement of the SYT1/SYT5 EPCS complexes. We propose that the observed EPCS rearrangements act as a slow adaptive response to sustained stress conditions, and that this process involves the accumulation of stress-specific phosphoinositides species at the PM.}, author = {Lee, E and Vila Nova Santana, B and Samuels, E and Benitez-Fuente, F and Corsi, E and Botella, MA and Perez-Sancho, J and Vanneste, S and Friml, Jiří and Macho, A and Alves Azevedo, A and Rosado, A}, issn = {1460-2431}, journal = {Journal of Experimental Botany}, number = {14}, pages = {3986–3998}, publisher = {Oxford University Press}, title = {{Rare earth elements induce cytoskeleton-dependent and PI4P-associated rearrangement of SYT1/SYT5 ER-PM contact site complexes in Arabidopsis}}, doi = {10.1093/jxb/eraa138}, volume = {71}, year = {2020}, } @article{7686, abstract = {The agricultural green revolution spectacularly enhanced crop yield and lodging resistance with modified DELLA-mediated gibberellin signaling. However, this was achieved at the expense of reduced nitrogen-use efficiency (NUE). Recently, Wu et al. revealed novel gibberellin signaling that provides a blueprint for improving tillering and NUE in Green Revolution varieties (GRVs). }, author = {Xue, Huidan and Zhang, Yuzhou and Xiao, Guanghui}, issn = {1360-1385}, journal = {Trends in Plant Science}, number = {6}, pages = {520--522}, publisher = {Elsevier}, title = {{Neo-gibberellin signaling: Guiding the next generation of the green revolution}}, doi = {10.1016/j.tplants.2020.04.001}, volume = {25}, year = {2020}, } @article{7695, abstract = {The TPLATE complex (TPC) is a key endocytic adaptor protein complex in plants. TPC in Arabidopsis (Arabidopsis thaliana) contains six evolutionarily conserved subunits and two plant-specific subunits, AtEH1/Pan1 and AtEH2/Pan1, although cytoplasmic proteins are not associated with the hexameric subcomplex in the cytoplasm. To investigate the dynamic assembly of the octameric TPC at the plasma membrane (PM), we performed state-of-the-art dual-color live cell imaging at physiological and lowered temperatures. Lowering the temperature slowed down endocytosis, thereby enhancing the temporal resolution of the differential recruitment of endocytic components. Under both normal and lowered temperature conditions, the core TPC subunit TPLATE and the AtEH/Pan1 proteins exhibited simultaneous recruitment at the PM. These results, together with co-localization analysis of different TPC subunits, allow us to conclude that TPC in plant cells is not recruited to the PM sequentially but as an octameric complex.}, author = {Wang, J and Mylle, E and Johnson, Alexander J and Besbrugge, N and De Jaeger, G and Friml, Jiří and Pleskot, R and van Damme, D}, issn = {1532-2548}, journal = {Plant Physiology}, number = {3}, pages = {986--997}, publisher = {American Society of Plant Biologists}, title = {{High temporal resolution reveals simultaneous plasma membrane recruitment of TPLATE complex subunits}}, doi = {10.1104/pp.20.00178}, volume = {183}, year = {2020}, } @article{7697, abstract = {* Morphogenesis and adaptive tropic growth in plants depend on gradients of the phytohormone auxin, mediated by the membrane‐based PIN‐FORMED (PIN) auxin transporters. PINs localize to a particular side of the plasma membrane (PM) or to the endoplasmic reticulum (ER) to directionally transport auxin and maintain intercellular and intracellular auxin homeostasis, respectively. However, the molecular cues that confer their diverse cellular localizations remain largely unknown. * In this study, we systematically swapped the domains between ER‐ and PM‐localized PIN proteins, as well as between apical and basal PM‐localized PINs from Arabidopsis thaliana , to shed light on why PIN family members with similar topological structures reside at different membrane compartments within cells. * Our results show that not only do the N‐ and C‐terminal transmembrane domains (TMDs) and central hydrophilic loop contribute to their differential subcellular localizations and cellular polarity, but that the pairwise‐matched N‐ and C‐terminal TMDs resulting from intramolecular domain–domain coevolution are also crucial for their divergent patterns of localization. * These findings illustrate the complexity of the evolutionary path of PIN proteins in acquiring their plethora of developmental functions and adaptive growth in plants.}, author = {Zhang, Yuzhou and Hartinger, Corinna and Wang, Xiaojuan and Friml, Jiří}, issn = {1469-8137}, journal = {New Phytologist}, number = {5}, pages = {1406--1416}, publisher = {Wiley}, title = {{Directional auxin fluxes in plants by intramolecular domain‐domain co‐evolution of PIN auxin transporters}}, doi = {10.1111/nph.16629}, volume = {227}, year = {2020}, } @article{7793, abstract = {Hormonal signalling in animals often involves direct transcription factor-hormone interactions that modulate gene expression. In contrast, plant hormone signalling is most commonly based on de-repression via the degradation of transcriptional repressors. Recently, we uncovered a non-canonical signalling mechanism for the plant hormone auxin whereby auxin directly affects the activity of the atypical auxin response factor (ARF), ETTIN towards target genes without the requirement for protein degradation. Here we show that ETTIN directly binds auxin, leading to dissociation from co-repressor proteins of the TOPLESS/TOPLESS-RELATED family followed by histone acetylation and induction of gene expression. This mechanism is reminiscent of animal hormone signalling as it affects the activity towards regulation of target genes and provides the first example of a DNA-bound hormone receptor in plants. Whilst auxin affects canonical ARFs indirectly by facilitating degradation of Aux/IAA repressors, direct ETTIN-auxin interactions allow switching between repressive and de-repressive chromatin states in an instantly-reversible manner.}, author = {Kuhn, André and Ramans Harborough, Sigurd and McLaughlin, Heather M and Natarajan, Bhavani and Verstraeten, Inge and Friml, Jiří and Kepinski, Stefan and Østergaard, Lars}, issn = {2050-084X}, journal = {eLife}, publisher = {eLife Sciences Publications}, title = {{Direct ETTIN-auxin interaction controls chromatin states in gynoecium development}}, doi = {10.7554/elife.51787}, volume = {9}, year = {2020}, } @article{7949, abstract = {Peptides derived from non-functional precursors play important roles in various developmental processes, but also in (a)biotic stress signaling. Our (phospho)proteome-wide analyses of C-terminally encoded peptide 5 (CEP5)-mediated changes revealed an impact on abiotic stress-related processes. Drought has a dramatic impact on plant growth, development and reproduction, and the plant hormone auxin plays a role in drought responses. Our genetic, physiological, biochemical and pharmacological results demonstrated that CEP5-mediated signaling is relevant for osmotic and drought stress tolerance in Arabidopsis, and that CEP5 specifically counteracts auxin effects. Specifically, we found that CEP5 signaling stabilizes AUX/IAA transcriptional repressors, suggesting the existence of a novel peptide-dependent control mechanism that tunes auxin signaling. These observations align with the recently described role of AUX/IAAs in stress tolerance and provide a novel role for CEP5 in osmotic and drought stress tolerance.}, author = {Smith, S and Zhu, S and Joos, L and Roberts, I and Nikonorova, N and Vu, LD and Stes, E and Cho, H and Larrieu, A and Xuan, W and Goodall, B and van de Cotte, B and Waite, JM and Rigal, A and R Harborough, SR and Persiau, G and Vanneste, S and Kirschner, GK and Vandermarliere, E and Martens, L and Stahl, Y and Audenaert, D and Friml, Jiří and Felix, G and Simon, R and Bennett, M and Bishopp, A and De Jaeger, G and Ljung, K and Kepinski, S and Robert, S and Nemhauser, J and Hwang, I and Gevaert, K and Beeckman, T and De Smet, I}, issn = {1535-9484}, journal = {Molecular & Cellular Proteomics}, number = {8}, pages = {1248--1262}, publisher = {American Society for Biochemistry and Molecular Biology}, title = {{The CEP5 peptide promotes abiotic stress tolerance, as revealed by quantitative proteomics, and attenuates the AUX/IAA equilibrium in Arabidopsis}}, doi = {10.1074/mcp.ra119.001826}, volume = {19}, year = {2020}, } @article{8138, abstract = {Directional transport of the phytohormone auxin is a versatile, plant-specific mechanism regulating many aspects of plant development. The recently identified plant hormones, strigolactones (SLs), are implicated in many plant traits; among others, they modify the phenotypic output of PIN-FORMED (PIN) auxin transporters for fine-tuning of growth and developmental responses. Here, we show in pea and Arabidopsis that SLs target processes dependent on the canalization of auxin flow, which involves auxin feedback on PIN subcellular distribution. D14 receptor- and MAX2 F-box-mediated SL signaling inhibits the formation of auxin-conducting channels after wounding or from artificial auxin sources, during vasculature de novo formation and regeneration. At the cellular level, SLs interfere with auxin effects on PIN polar targeting, constitutive PIN trafficking as well as clathrin-mediated endocytosis. Our results identify a non-transcriptional mechanism of SL action, uncoupling auxin feedback on PIN polarity and trafficking, thereby regulating vascular tissue formation and regeneration.}, author = {Zhang, J and Mazur, E and Balla, J and Gallei, Michelle C and Kalousek, P and Medveďová, Z and Li, Y and Wang, Y and Prat, Tomas and Vasileva, Mina K and Reinöhl, V and Procházka, S and Halouzka, R and Tarkowski, P and Luschnig, C and Brewer, PB and Friml, Jiří}, issn = {2041-1723}, journal = {Nature Communications}, number = {1}, pages = {3508}, publisher = {Springer Nature}, title = {{Strigolactones inhibit auxin feedback on PIN-dependent auxin transport canalization}}, doi = {10.1038/s41467-020-17252-y}, volume = {11}, year = {2020}, } @article{8271, author = {He, Peng and Zhang, Yuzhou and Xiao, Guanghui}, issn = {1752-9867}, journal = {Molecular Plant}, number = {9}, pages = {1238--1240}, publisher = {Elsevier}, title = {{Origin of a subgenome and genome evolution of allotetraploid cotton species}}, doi = {10.1016/j.molp.2020.07.006}, volume = {13}, year = {2020}, } @article{8337, abstract = {Cytokinins are mobile multifunctional plant hormones with roles in development and stress resilience. Although their Histidine Kinase receptors are substantially localised to the endoplasmic reticulum, cellular sites of cytokinin perception and importance of spatially heterogeneous cytokinin distribution continue to be debated. Here we show that cytokinin perception by plasma membrane receptors is an effective additional path for cytokinin response. Readout from a Two Component Signalling cytokinin-specific reporter (TCSn::GFP) closely matches intracellular cytokinin content in roots, yet we also find cytokinins in extracellular fluid, potentially enabling action at the cell surface. Cytokinins covalently linked to beads that could not pass the plasma membrane increased expression of both TCSn::GFP and Cytokinin Response Factors. Super-resolution microscopy of GFP-labelled receptors and diminished TCSn::GFP response to immobilised cytokinins in cytokinin receptor mutants, further indicate that receptors can function at the cell surface. We argue that dual intracellular and surface locations may augment flexibility of cytokinin responses.}, author = {Antoniadi, Ioanna and Novák, Ondřej and Gelová, Zuzana and Johnson, Alexander J and Plíhal, Ondřej and Simerský, Radim and Mik, Václav and Vain, Thomas and Mateo-Bonmatí, Eduardo and Karady, Michal and Pernisová, Markéta and Plačková, Lenka and Opassathian, Korawit and Hejátko, Jan and Robert, Stéphanie and Friml, Jiří and Doležal, Karel and Ljung, Karin and Turnbull, Colin}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Cell-surface receptors enable perception of extracellular cytokinins}}, doi = {10.1038/s41467-020-17700-9}, volume = {11}, year = {2020}, } @article{8607, abstract = {Clathrin-mediated endocytosis (CME) and its core endocytic machinery are evolutionarily conserved across all eukaryotes. In mammals, the heterotetrameric adaptor protein complex-2 (AP-2) sorts plasma membrane (PM) cargoes into vesicles through the recognition of motifs based on tyrosine or di-leucine in their cytoplasmic tails. However, in plants, very little is known on how PM proteins are sorted for CME and whether similar motifs are required. In Arabidopsis thaliana, the brassinosteroid (BR) receptor, BR INSENSITIVE1 (BRI1), undergoes endocytosis that depends on clathrin and AP-2. Here we demonstrate that BRI1 binds directly to the medium AP-2 subunit, AP2M. The cytoplasmic domain of BRI1 contains five putative canonical surface-exposed tyrosine-based endocytic motifs. The tyrosine-to-phenylalanine substitution in Y898KAI reduced BRI1 internalization without affecting its kinase activity. Consistently, plants carrying the BRI1Y898F mutation were hypersensitive to BRs. Our study demonstrates that AP-2-dependent internalization of PM proteins via the recognition of functional tyrosine motifs also operates in plants.}, author = {Liu, D and Kumar, R and LAN, Claus and Johnson, Alexander J and Siao, W and Vanhoutte, I and Wang, P and Bender, KW and Yperman, K and Martins, S and Zhao, X and Vert, G and Van Damme, D and Friml, Jiří and Russinova, E}, issn = {1532-298x}, journal = {Plant Cell}, number = {11}, pages = {3598--3612}, publisher = {American Society of Plant Biologists}, title = {{Endocytosis of BRASSINOSTEROID INSENSITIVE1 is partly driven by a canonical tyrosine-based Motif}}, doi = {10.1105/tpc.20.00384}, volume = {32}, year = {2020}, }