Uncovering natural variation in root system architecture and growth dynamics using a robotics-assisted phenomics platform

The plant kingdom contains a stunning array of complex morphologies easily observed above-ground, but more challenging to visualize below-ground. Understanding the magnitude of diversity in root distribution within the soil, termed root system architecture (RSA), is fundamental in determining how this trait contributes to species adaptation in local environments. Roots are the interface between the soil environment and the shoot system and therefore play a key role in anchorage, resource uptake, and stress resilience. Previously, we presented the GLO-Roots (Growth and Luminescence Observatory for Roots) system to study the RSA of soil-grown Arabidopsis thaliana plants from germination to maturity (Rellán-Álvarez et al., 2015). In this study, we present the automation of GLO-Roots using robotics and the development of image analysis pipelines in order to examine the temporal dynamic regulation of RSA and the broader natural variation of RSA in Arabidopsis, over time. These datasets describe the developmental dynamics of two independent panels of accessions and reveal highly complex and polygenic RSA traits that show significant correlation with climate variables of the accessions’ respective origins

Integrating biological vasculature into a multi-organ-chip microsystem

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.A chip-based system mimicking the transport function of the human cardiovascular system has been established at minute but standardized microsystem scale. A peristaltic on-chip micropump generates pulsatile shear stress in a widely adjustable physiological range within a microchannel circuit entirely covered on all fluid contact surfaces with human dermal microvascular endothelial cells. This microvascular transport system can be reproducibly established within four days, independently of the individual endothelial cell donor background. It interconnects two standard tissue culture compartments, each of 5 mm diameter, through microfluidic channels of 500 μm width. Further vessel branching and vessel diameter reduction down to a microvessel scale of approximately 40 μm width was realised by a two-photon laser ablation technique applied to inserts, designed for the convenient establishment of individual organ equivalents in the tissue culture compartments at a later time. The chip layout ensures physiological fluid-to-tissue ratios. Moreover, an in-depth microscopic analysis revealed the fine-tuned adjustment of endothelial cell behaviour to local shear stresses along the microvasculature of the system. Time-lapse and 3D imaging two-photon microscopy were used to visualise details of spatiotemporal adherence of the endothelial cells to the channel system and to each other. The first indicative long-term experiments revealed stable performance over two and four weeks. The potential application of this system for the future establishment of human-on-a-chip systems and basic human endothelial cell research is discussed.BMBF, 0315569, GO-Bio 3: Multi-Organ-Bioreaktoren für die prädiktive Substanztestung im Chipforma

Opposite polarity programs regulate asymmetric subsidiary cell divisions in grasses.

Grass stomata recruit lateral subsidiary cells (SCs), which are key to the unique stomatal morphology and the efficient plant-atmosphere gas exchange in grasses. Subsidiary mother cells (SMCs) strongly polarise before an asymmetric division forms a SC. Yet apart from a proximal polarity module that includes PANGLOSS1 (PAN1) and guides nuclear migration, little is known regarding the developmental processes that form SCs. Here, we used comparative transcriptomics of developing wild-type and SC-less bdmute leaves in the genetic model grass Brachypodium distachyon to identify novel factors involved in SC formation. This approach revealed BdPOLAR, which forms a novel, distal polarity domain in SMCs that is opposite to the proximal PAN1 domain. Both polarity domains are required for the formative SC division yet exhibit various roles in guiding pre-mitotic nuclear migration and SMC division plane orientation, respectively. Nonetheless, the domains are linked as the proximal domain controls polarisation of the distal domain. In summary, we identified two opposing polarity domains that coordinate the SC division, a process crucial for grass stomatal physiology

SARS-CoV-2 Variant of Concern B.1.1.7: Diagnostic Sensitivity of Three Antigen-Detecting Rapid Tests.

Funder: Foundation for Innovative New DiagnosticsFunder: World Health OrganizationFunder: Ministry of Science, Research and Culture, State of Baden Wuerttemberg, German

Schwerpunkt: Rechtsextremismus und Soziale Arbeit

Das SI:SO-Heft widmet sich den folgenden Fragen: - Unter welchen Gesichtspunkten lassen sich Rechtspopulismus und Rechtsextremismus differenziert diskutieren? - Wie werden Rechtsextreme bestimmt und Rechtsextremismus identifiziert? - Inwiefern ist Soziale Arbeit von Rechtsextremismus und Rechtspopulismus betroffen? - Welche Kritiken gelten als zulässig, welche nicht und welche Auseinandersetzungen werden in der Sozialen Arbeit gemieden? - Welche politischen und zivilgesellschaftlichen Beiträge leistet Soziale Arbeit im Phänomenbereich Rechtsextremismus und Rechtspopulismus? - Welche Folgen ergeben sich für Hochschulen und Studium im Umgang mit Rechtsextremismus und Rechtspopulismus

Trinitarische Denkbewegungen als Bildungspotenzial. Ein Plädoyer für die Aufhebung didaktischer Unterkomplexität im Religionsunterricht

Festschrift für Michael Meyer-Blanc