@article{8582, abstract = {Cell and tissue polarization is fundamental for plant growth and morphogenesis. The polar, cellular localization of Arabidopsis PIN‐FORMED (PIN) proteins is crucial for their function in directional auxin transport. The clustering of PIN polar cargoes within the plasma membrane has been proposed to be important for the maintenance of their polar distribution. However, the more detailed features of PIN clusters and the cellular requirements of cargo clustering remain unclear. Here, we characterized PIN clusters in detail by means of multiple advanced microscopy and quantification methods, such as 3D quantitative imaging or freeze‐fracture replica labeling. The size and aggregation types of PIN clusters were determined by electron microscopy at the nanometer level at different polar domains and at different developmental stages, revealing a strong preference for clustering at the polar domains. Pharmacological and genetic studies revealed that PIN clusters depend on phosphoinositol pathways, cytoskeletal structures and specific cell‐wall components as well as connections between the cell wall and the plasma membrane. This study identifies the role of different cellular processes and structures in polar cargo clustering and provides initial mechanistic insight into the maintenance of polarity in plants and other systems.}, author = {Li, Hongjiang and von Wangenheim, Daniel and Zhang, Xixi and Tan, Shutang and Darwish-Miranda, Nasser and Naramoto, Satoshi and Wabnik, Krzysztof T and de Rycke, Riet and Kaufmann, Walter and Gütl, Daniel J and Tejos, Ricardo and Grones, Peter and Ke, Meiyu and Chen, Xu and Dettmer, Jan and Friml, Jiří}, issn = {14698137}, journal = {New Phytologist}, number = {1}, pages = {351--369}, publisher = {Wiley}, title = {{Cellular requirements for PIN polar cargo clustering in Arabidopsis thaliana}}, doi = {10.1111/nph.16887}, volume = {229}, year = {2021}, } @article{146, abstract = {The root cap protects the stem cell niche of angiosperm roots from damage. In Arabidopsis, lateral root cap (LRC) cells covering the meristematic zone are regularly lost through programmed cell death, while the outermost layer of the root cap covering the tip is repeatedly sloughed. Efficient coordination with stem cells producing new layers is needed to maintain a constant size of the cap. We present a signalling pair, the peptide IDA-LIKE1 (IDL1) and its receptor HAESA-LIKE2 (HSL2), mediating such communication. Live imaging over several days characterized this process from initial fractures in LRC cell files to full separation of a layer. Enhanced expression of IDL1 in the separating root cap layers resulted in increased frequency of sloughing, balanced with generation of new layers in a HSL2-dependent manner. Transcriptome analyses linked IDL1-HSL2 signalling to the transcription factors BEARSKIN1/2 and genes associated with programmed cell death. Mutations in either IDL1 or HSL2 slowed down cell division, maturation and separation. Thus, IDL1-HSL2 signalling potentiates dynamic regulation of the homeostatic balance between stem cell division and sloughing activity.}, author = {Shi, Chun Lin and Von Wangenheim, Daniel and Herrmann, Ullrich and Wildhagen, Mari and Kulik, Ivan and Kopf, Andreas and Ishida, Takashi and Olsson, Vilde and Anker, Mari Kristine and Albert, Markus and Butenko, Melinka A and Felix, Georg and Sawa, Shinichiro and Claassen, Manfred and Friml, Jirí and Aalen, Reidunn B}, journal = {Nature Plants}, number = {8}, pages = {596 -- 604}, publisher = {Nature Publishing Group}, title = {{The dynamics of root cap sloughing in Arabidopsis is regulated by peptide signalling}}, doi = {10.1038/s41477-018-0212-z}, volume = {4}, year = {2018}, } @article{1078, abstract = {One of the key questions in understanding plant development is how single cells behave in a larger context of the tissue. Therefore, it requires the observation of the whole organ with a high spatial- as well as temporal resolution over prolonged periods of time, which may cause photo-toxic effects. This protocol shows a plant sample preparation method for light-sheet microscopy, which is characterized by mounting the plant vertically on the surface of a gel. The plant is mounted in such a way that the roots are submerged in a liquid medium while the leaves remain in the air. In order to ensure photosynthetic activity of the plant, a custom-made lighting system illuminates the leaves. To keep the roots in darkness the water surface is covered with sheets of black plastic foil. This method allows long-term imaging of plant organ development in standardized conditions. }, author = {Von Wangenheim, Daniel and Hauschild, Robert and Friml, Jirí}, journal = {Journal of visualized experiments JoVE}, number = {119}, publisher = {Journal of Visualized Experiments}, title = {{Light sheet fluorescence microscopy of plant roots growing on the surface of a gel}}, doi = {10.3791/55044}, volume = {2017}, year = {2017}, } @article{722, abstract = {Plants are sessile organisms rooted in one place. The soil resources that plants require are often distributed in a highly heterogeneous pattern. To aid foraging, plants have evolved roots whose growth and development are highly responsive to soil signals. As a result, 3D root architecture is shaped by myriad environmental signals to ensure resource capture is optimised and unfavourable environments are avoided. The first signals sensed by newly germinating seeds — gravity and light — direct root growth into the soil to aid seedling establishment. Heterogeneous soil resources, such as water, nitrogen and phosphate, also act as signals that shape 3D root growth to optimise uptake. Root architecture is also modified through biotic interactions that include soil fungi and neighbouring plants. This developmental plasticity results in a ‘custom-made’ 3D root system that is best adapted to forage for resources in each soil environment that a plant colonises.}, author = {Morris, Emily and Griffiths, Marcus and Golebiowska, Agata and Mairhofer, Stefan and Burr Hersey, Jasmine and Goh, Tatsuaki and Von Wangenheim, Daniel and Atkinson, Brian and Sturrock, Craig and Lynch, Jonathan and Vissenberg, Kris and Ritz, Karl and Wells, Darren and Mooney, Sacha and Bennett, Malcolm}, issn = {09609822}, journal = {Current Biology}, number = {17}, pages = {R919 -- R930}, publisher = {Cell Press}, title = {{Shaping 3D root system architecture}}, doi = {10.1016/j.cub.2017.06.043}, volume = {27}, year = {2017}, } @article{525, abstract = {The Casparian strip is an important barrier regulating water and nutrient uptake into root tissues. New research reveals two peptide signals and their co-receptors play critical roles patterning and maintaining barrier integrity. }, author = {Daniel von Wangenheim and Goh, Tatsuaki and Dietrich, Daniela and Bennett, Malcolm J}, journal = {Current Biology}, number = {5}, pages = {R172 -- R174}, publisher = {Cell Press}, title = {{Plant biology: Building barriers… in roots}}, doi = {10.1016/j.cub.2017.01.060}, volume = {27}, year = {2017}, } @misc{5565, abstract = {One of the key questions in understanding plant development is how single cells behave in a larger context of the tissue. Therefore, it requires the observation of the whole organ with a high spatial- as well as temporal resolution over prolonged periods of time, which may cause photo-toxic effects. This protocol shows a plant sample preparation method for light-sheet microscopy, which is characterized by mounting the plant vertically on the surface of a gel. The plant is mounted in such a way that the roots are submerged in a liquid medium while the leaves remain in the air. In order to ensure photosynthetic activity of the plant, a custom-made lighting system illuminates the leaves. To keep the roots in darkness the water surface is covered with sheets of black plastic foil. This method allows long-term imaging of plant organ development in standardized conditions. The Video is licensed under a CC BY NC ND license. }, author = {Von Wangenheim, Daniel and Hauschild, Robert and Friml, Jirí}, publisher = {Institute of Science and Technology Austria}, title = {{Light Sheet Fluorescence microscopy of plant roots growing on the surface of a gel}}, doi = {10.15479/AT:ISTA:66}, year = {2017}, } @article{946, abstract = {Roots navigate through soil integrating environmental signals to orient their growth. The Arabidopsis root is a widely used model for developmental, physiological and cell biological studies. Live imaging greatly aids these efforts, but the horizontal sample position and continuous root tip displacement present significant difficulties. Here, we develop a confocal microscope setup for vertical sample mounting and integrated directional illumination. We present TipTracker – a custom software for automatic tracking of diverse moving objects usable on various microscope setups. Combined, this enables observation of root tips growing along the natural gravity vector over prolonged periods of time, as well as the ability to induce rapid gravity or light stimulation. We also track migrating cells in the developing zebrafish embryo, demonstrating the utility of this system in the acquisition of high-resolution data sets of dynamic samples. We provide detailed descriptions of the tools enabling the easy implementation on other microscopes.}, author = {Von Wangenheim, Daniel and Hauschild, Robert and Fendrych, Matyas and Barone, Vanessa and Benková, Eva and Friml, Jirí}, journal = {eLife}, publisher = {eLife Sciences Publications}, title = {{Live tracking of moving samples in confocal microscopy for vertically grown roots}}, doi = {10.7554/eLife.26792}, volume = {6}, year = {2017}, } @article{526, abstract = {Plants form new organs with patterned tissue organization throughout their lifespan. It is unknown whether this robust post-embryonic organ formation results from stereotypic dynamic processes, in which the arrangement of cells follows rigid rules. Here, we combine modeling with empirical observations of whole-organ development to identify the principles governing lateral root formation in Arabidopsis. Lateral roots derive from a small pool of founder cells in which some take a dominant role as seen by lineage tracing. The first division of the founders is asymmetric, tightly regulated, and determines the formation of a layered structure. Whereas the pattern of subsequent cell divisions is not stereotypic between different samples, it is characterized by a regular switch in division plane orientation. This switch is also necessary for the appearance of patterned layers as a result of the apical growth of the primordium. Our data suggest that lateral root morphogenesis is based on a limited set of rules. They determine cell growth and division orientation. The organ-level coupling of the cell behavior ensures the emergence of the lateral root's characteristic features. We propose that self-organizing, non-deterministic modes of development account for the robustness of plant organ morphogenesis.}, author = {Daniel von Wangenheim and Fangerau, Jens and Schmitz, Alexander and Smith, Richard S and Leitte, Heike and Stelzer, Ernst H and Maizel, Alexis}, journal = {Current Biology}, number = {4}, pages = {439 -- 449}, publisher = {Cell Press}, title = {{Rules and self-organizing properties of post-embryonic plant organ cell division patterns}}, doi = {10.1016/j.cub.2015.12.047}, volume = {26}, year = {2016}, } @article{1238, abstract = {The dynamic localization of endosomal compartments labeled with targeted fluorescent protein tags is routinely followed by time lapse fluorescence microscopy approaches and single particle tracking algorithms. In this way trajectories of individual endosomes can be mapped and linked to physiological processes as cell growth. However, other aspects of dynamic behavior including endosomal interactions are difficult to follow in this manner. Therefore, we characterized the localization and dynamic properties of early and late endosomes throughout the entire course of root hair formation by means of spinning disc time lapse imaging and post-acquisition automated multitracking and quantitative analysis. Our results show differential motile behavior of early and late endosomes and interactions of late endosomes that may be specified to particular root hair domains. Detailed data analysis revealed a particular transient interaction between late endosomes—termed herein as dancing-endosomes—which is not concluding to vesicular fusion. Endosomes preferentially located in the root hair tip interacted as dancing-endosomes and traveled short distances during this interaction. Finally, sizes of early and late endosomes were addressed by means of super-resolution structured illumination microscopy (SIM) to corroborate measurements on the spinning disc. This is a first study providing quantitative microscopic data on dynamic spatio-temporal interactions of endosomes during root hair tip growth.}, author = {Von Wangenheim, Daniel and Rosero, Amparo and Komis, George and Šamajová, Olga and Ovečka, Miroslav and Voigt, Boris and Šamaj, Jozef}, journal = {Frontiers in Plant Science}, number = {JAN2016}, publisher = {Frontiers Research Foundation}, title = {{Endosomal interactions during root hair growth}}, doi = {10.3389/fpls.2015.01262}, volume = {6}, year = {2016}, } @article{2844, abstract = {As soon as a seed germinates, plant growth relates to gravity to ensure that the root penetrates the soil and the shoot expands aerially. Whereas mechanisms of positive and negative orthogravitropism of primary roots and shoots are relatively well understood [1-3], lateral organs often show more complex growth behavior [4]. Lateral roots (LRs) seemingly suppress positive gravitropic growth and show a defined gravitropic set-point angle (GSA) that allows radial expansion of the root system (plagiotropism) [3, 4]. Despite its eminent importance for root architecture, it so far remains completely unknown how lateral organs partially suppress positive orthogravitropism. Here we show that the phytohormone auxin steers GSA formation and limits positive orthogravitropism in LR. Low and high auxin levels/signaling lead to radial or axial root systems, respectively. At a cellular level, it is the auxin transport-dependent regulation of asymmetric growth in the elongation zone that determines GSA. Our data suggest that strong repression of PIN4/PIN7 and transient PIN3 expression limit auxin redistribution in young LR columella cells. We conclude that PIN activity, by temporally limiting the asymmetric auxin fluxes in the tip of LRs, induces transient, differential growth responses in the elongation zone and, consequently, controls root architecture.}, author = {Rosquete, Michel and Von Wangenheim, Daniel and Marhavy, Peter and Barbez, Elke and Stelzer, Ernst and Benková, Eva and Maizel, Alexis and Kleine Vehn, Jürgen}, journal = {Current Biology}, number = {9}, pages = {817 -- 822}, publisher = {Cell Press}, title = {{An auxin transport mechanism restricts positive orthogravitropism in lateral roots}}, doi = {10.1016/j.cub.2013.03.064}, volume = {23}, year = {2013}, }