Translate text to:
In JoVE (1)
Other Publications (9)
Articles by Daniel von Wangenheim in JoVE
Light Sheet Fluorescence Microscopy of Plant Roots Growing on the Surface of a Gel
Daniel von Wangenheim1, Robert Hauschild2, Jiří Friml1
1Developmental and Cell Biology of Plants, Institute of Science and Technology Austria, 2Bioimaging Facility, Institute of Science and Technology Austria
Other articles by Daniel von Wangenheim on PubMed
High-resolution Live Imaging of Plant Growth in Near Physiological Bright Conditions Using Light Sheet Fluorescence Microscopy
The Plant Journal : for Cell and Molecular Biology. Oct, 2011 | Pubmed ID: 21711399
Most plant growth occurs post-embryonically and is characterized by the constant and iterative formation of new organs. Non-invasive time-resolved imaging of intact, fully functional organisms allows studies of the dynamics involved in shaping complex organisms. Conventional and confocal fluorescence microscopy suffer from limitations when whole living organisms are imaged at single-cell resolution. We applied light sheet-based fluorescence microscopy to overcome these limitations and study the dynamics of plant growth. We designed a special imaging chamber in which the plant is maintained vertically under controlled illumination with its leaves in the air and its root in the medium. We show that minimally invasive, multi-color, three-dimensional imaging of live Arabidopsis thaliana samples can be achieved at organ, cellular and subcellular scales over periods of time ranging from seconds to days with minimal damage to the sample. We illustrate the capabilities of the method by recording the growth of primary root tips and lateral root primordia over several hours. This allowed us to quantify the contribution of cell elongation to the early morphogenesis of lateral root primordia and uncover the diurnal growth rhythm of lateral roots. We demonstrate the applicability of our approach at varying spatial and temporal scales by following the division of plant cells as well as the movement of single endosomes in live growing root samples. This multi-dimensional approach will have an important impact on plant developmental and cell biology and paves the way to a truly quantitative description of growth processes at several scales.
Protoplasma. Jun, 2012 | Pubmed ID: 22183127
Intracellular organelle movements and positioning play pivotal roles in enabling plants to proliferate life efficiently and to survive diverse environmental stresses. The elaborate dissection of organelle dynamics and their underlying mechanisms (e.g., the role of the cytoskeleton in organelle movements) largely depends on the advancement and efficiency of organelle tracking systems. Here, we provide an overview of some recently developed tools for labeling and tracking organelle dynamics in living plant cells.
Proceedings of the National Academy of Sciences of the United States of America. Mar, 2013 | Pubmed ID: 23479644
In Arabidopsis, lateral root primordia (LRPs) originate from pericycle cells located deep within the parental root and have to emerge through endodermal, cortical, and epidermal tissues. These overlaying tissues place biomechanical constraints on the LRPs that are likely to impact their morphogenesis. This study probes the interplay between the patterns of cell division, organ shape, and overlaying tissues on LRP morphogenesis by exploiting recent advances in live plant cell imaging and image analysis. Our 3D/4D image analysis revealed that early stage LRPs exhibit tangential divisions that create a ring of cells corralling a population of rapidly dividing cells at its center. The patterns of division in the latter population of cells during LRP morphogenesis are not stereotypical. In contrast, statistical analysis demonstrated that the shape of new LRPs is highly conserved. We tested the relative importance of cell division pattern versus overlaying tissues on LRP morphogenesis using mutant and transgenic approaches. The double mutant aurora1 (aur1) aur2 disrupts the pattern of LRP cell divisions and impacts its growth dynamics, yet the new organ's dome shape remains normal. In contrast, manipulating the properties of overlaying tissues disrupted LRP morphogenesis. We conclude that the interaction with overlaying tissues, rather than the precise pattern of divisions, is most important for LRP morphogenesis and optimizes the process of lateral root emergence.
Current Biology : CB. May, 2013 | Pubmed ID: 23583551
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, lateral organs often show more complex growth behavior. 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). 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.
Methods in Molecular Biology (Clifton, N.J.). 2014 | Pubmed ID: 24057385
Live cell imaging is an essential methodology for studying the structure, dynamics, and functions of cells in a living plant under normal or stressed growth conditions. Arabidopsis thaliana is perfectly amenable to various live microscopy techniques. In this chapter, we provide guidelines to design live-imaging experiments. We discuss specifically the respective advantage of each microscopy technique, the choice of reporter, and the preparation of the sample. Detailed protocols for imaging of shoot and roots are provided.
Science (New York, N.Y.). Jan, 2014 | Pubmed ID: 24408432
Lateral root formation in plants can be studied as the process of interaction between chemical signals and physical forces during development. Lateral root primordia grow through overlying cell layers that must accommodate this incursion. Here, we analyze responses of the endodermis, the immediate neighbor to an initiating lateral root. Endodermal cells overlying lateral root primordia lose volume, change shape, and relinquish their tight junction-like diffusion barrier to make way for the emerging lateral root primordium. Endodermal feedback is absolutely required for initiation and growth of lateral roots, and we provide evidence that this is mediated by controlled volume loss in the endodermis. We propose that turgidity and rigid cell walls, typical of plants, impose constraints that are specifically modified for a given developmental process.
Trans-Golgi Network Localized Small GTPase RabA1d is Involved in Cell Plate Formation and Oscillatory Root Hair Growth
BMC Plant Biology. Sep, 2014 | Pubmed ID: 25260869
Small Rab GTPases are important regulators of vesicular trafficking in plants. AtRabA1d, a member of the RabA1 subfamily of small GTPases, was previously found in the vesicle-rich apical dome of growing root hairs suggesting a role during tip growth; however, its specific intracellular localization and role in plants has not been well described.
Frontiers in Plant Science. 2015 | Pubmed ID: 26858728
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.
Current Biology : CB. Feb, 2016 | Pubmed ID: 26832441
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.