Cold priming on pathogen susceptibility in the Arabidopsis eds1 mutant background requires a functional stromal Ascorbate Peroxidase

24 h cold exposure (4°C) is sufficient to reduce pathogen susceptibility in Arabidopsis thaliana against the virulent Pseudomonas syringae pv. tomato (Pst) strain even when the infection occurs five days later. This priming effect is independent of the immune regulator Enhanced Disease Susceptibility 1 (EDS1) and can be observed in the immune-compromised eds1–2 null mutant. In contrast, cold priming-reduced Pst susceptibility is strongly impaired in knock-out lines of the stromal and thylakoid ascorbate peroxidases (sAPX/tAPX) highlighting their relevance for abiotic stress-related increased immune resilience. Here, we extended our analysis by generating an eds1 sapx double mutant. eds1 sapx showed eds1-like resistance and susceptibility phenotypes against Pst strains containing the effectors avrRPM1 and avrRPS4. In comparison to eds1–2, susceptibility against the wildtype Pst strain was constitutively enhanced in eds1 sapx. Although a prior cold priming exposure resulted in reduced Pst titers in eds1–2, it did not alter Pst resistance in eds1 sapx. This demonstrates that the genetic sAPX requirement for cold priming of basal plant immunity applies also to an eds1 null mutant background

Cold Exposure Memory Reduces Pathogen Susceptibility in Arabidopsis Based on a Functional Plastid Peroxidase System

Chloroplasts serve as cold priming hubs modulating the transcriptional response of Arabidopsis thaliana to a second cold stimulus for several days by postcold accumulation of thylakoid ascorbate peroxidases (tAPX). In an attempt to investigate cross-priming effects of cold on plant pathogen protection, we show here that such a single 24-h cold treatment at 4°C decreased the susceptibility of Arabidopsis to virulent Pseudomonas syringae pv. tomato DC3000 but did not alter resistance against the avirulent P. syringae pv. tomato avRPM1 and P. syringae pv. tomato avrRPS4 strains or the effector-deficient P. syringae pv. tomato strain hrcC−. The effect of cold priming against P. syringae pv. tomato was active immediately after cold exposure and memorized for at least 5 days. The priming benefit was established independent of the immune regulator Enhanced Disease Susceptibility 1 (EDS1) or activation of the immune-related genes NHL10, FRK1, ICS1 and PR1 but required thylakoid-bound as well as stromal ascorbate peroxidase activities because the effect was absent or weak in corresponding knock-out-lines. Suppression of tAPX postcold regulation in a conditional-inducible tAPX-RNAi line led to increased bacterial growth numbers. This highlights that the plant immune system benefits from postcold regeneration of the protective chloroplast peroxidase system

Cold priming on pathogen susceptibility in the Arabidopsis eds1 mutant background requires a functional stromal Ascorbate Peroxidase

24 h cold exposure (4°C) is sufficient to reduce pathogen susceptibility in Arabidopsis thaliana against the virulent Pseudomonas syringae pv. tomato (Pst) strain even when the infection occurs five days later. This priming effect is independent of the immune regulator Enhanced Disease Susceptibility 1 (EDS1) and can be observed in the immune-compromised eds1–2 null mutant. In contrast, cold priming-reduced Pst susceptibility is strongly impaired in knock-out lines of the stromal and thylakoid ascorbate peroxidases (sAPX/tAPX) highlighting their relevance for abiotic stress-related increased immune resilience. Here, we extended our analysis by generating an eds1 sapx double mutant. eds1 sapx showed eds1-like resistance and susceptibility phenotypes against Pst strains containing the effectors avrRPM1 and avrRPS4. In comparison to eds1–2, susceptibility against the wildtype Pst strain was constitutively enhanced in eds1 sapx. Although a prior cold priming exposure resulted in reduced Pst titers in eds1–2, it did not alter Pst resistance in eds1 sapx. This demonstrates that the genetic sAPX requirement for cold priming of basal plant immunity applies also to an eds1 null mutant background

Effects of Microstructure Modification by Friction Surfacing on Wear Behavior of Al Alloys with Different Si Contents

In this work, Al alloys with 6.6%, 10.4%, and 14.6% Si were deposited as thick coatings by Friction Surfacing (FS), resulting in grain refinement and spheroidization of needle-shaped eutectic Si phase. Lubricated sliding wear tests were performed on a pin-on-disc tribometer using Al-Si alloys in as-cast and FS processed states as pins and 42CrMo4 steel discs. The chemical composition of the worn surfaces was analyzed by X-ray photoelectron spectroscopy (XPS). The wear mechanisms were studied by scanning electron microscopy (SEM) and focused ion beam (FIB), and the wear was evaluated by measuring the weight loss of the samples. For the hypoeutectic alloys, spheroidization of the Si phase particles in particular leads to a significant improvement in wear resistance. The needle-shaped Si phase in as-cast state fractures during the wear test and small fragments easily detach from the surface. The spherical Si phase particles in the FS state also break away from the surface, but to a smaller extent. No reduction in wear due to FS was observed for the hypereutectic alloy. Here, large bulky primary Si phase particles are already present in the as-cast state and do not change significantly during FS, providing high wear resistance in both material states. This study highlights the mechanisms and limitations of improved wear resistance of Si-rich Al alloys deposited as thick coatings by Friction Surfacing

Political Skill Camouflages Machiavellianism: Career Role Performance and Organizational Misbehavior at Short and Long Tenure

On the basis of socioanalytic theory (Hogan & Shelton, 1998) and mimicry-deception theory (Jones, 2014), we hypothesized that political skill would effectively mask Machiavellianism (socioanalytic theory) with consequences for coworker perceived career role performance and actual counterproductive work behavior at low and high levels of job tenure (mimicrydeception theory). We tested our hypotheses in a triangular multisource design in two complementary studies comprised of both target workers and coworkers with a total of N = 1,438 participants. In Study 1, we found that when political skill was high, targets received high career role performance ratings from coworkers, and this was also the case when targets had high levels of Machiavellianism (socioanalytic masking effect). For targets with low political skill, the career role performance ratings of high Machiavellians was low at long tenure. The results of Study 2 partly disconfirmed mimicry-deception theory: Individuals high in Machiavellianism and high in political skill did not tend to avoid engaging in overtly mean behaviors toward others and extracting organizational resources at short tenure. Implications and limitations are discussed

MODUS-COVID Bericht vom 19.03.2021

Unser Bericht geht von folgenden Grundüberlegungen aus: Trotz Notbremse wird die dritte Welle im Maximum zu höheren Inzidenzen führen als die zweite Welle, da die Mutation B.1.1.7 deutlich ansteckender ist, als die bisherigen Virusvarianten. Nahezu alle Infektionen in unserem Modell beruhen auf ungeschützten Kontakten in Innenräumen. Wenn der R-Wert unter 1 gehalten werden soll, müssen zusätzliche Anstrengungen unternommen werden, um solche ungeschützten Kontakte zu reduzieren.BMBF, 01KX2022A, MODUS-COVID: Modellgestützte Untersuchung von Schulschließungen und weiteren Maßnahmen zur Eindämmung von Covid-19 - Teilprojekt 1: Urbane und regionale Simulation auf Basis von datengestützten, synthetischen Bewegungsprofile

MODUS-COVID Bericht vom 09.04.2021

Die uns zur Verfügung stehenden Mobilitätsdaten zeigen ein differenziertes Bild der Aktivitäten während der letzten Wochen: erhöhte Aktivitäten im Außenbereich vor Ostern, erhöhte Aktivitäten in Innenräumen während der Osterfeiertage, und seitdem ein gegenüber Ende Februar wieder abgesenktes Aktivitätsniveau. In der Analyse der zur Zeit geltenden Maßnahmen konzentrieren wir uns auf Berlin. Die dort angeordneten Maßnahmen adressieren die drei kritischen Bereiche Arbeit, Schulen, und private Besuche. Wenn alle diese Maßnahmen vollumfänglich wirksam wären und durch wärmeres Wetter zusätzliche Freizeitaktivitäten von innen nach außen verlegt würden, könnte dies laut unseren Simulationen insgesamt fast reichen, um den R-Wert unter 1 zu drücken. rere Personen gleichzeitig aufhalten; sehr gut wirksam wäre ein (fast) vollständiges Verbot privater Besuche, wie z.B. in Großbritannien am 5. Januar eingeführt. Im Sinne des oben gesagten kommt als “harter aber kurzer” Lockdown eigentlich nur das nahezu vollständige Verbot privater Kontakte in Frage; nur diese Maßnahme senkt die Infektionszahlen innerhalb von drei Wochen sehr deutlich.BMBF, 01KX2022A, MODUS-COVID: Modellgestützte Untersuchung von Schulschließungen und weiteren Maßnahmen zur Eindämmung von Covid-19 - Teilprojekt 1: Urbane und regionale Simulation auf Basis von datengestützten, synthetischen Bewegungsprofile

The Lancet Countdown on health and climate change: from 25 years of inaction to a global transformation for public health

Climate change underpins all the social and environmental determinants of health but also has positive implications. The Lancet Countdown: Tracking Progress on Health and Climate Change is an international, multi-disciplinary research collaboration between academic institutions following on from the 2015 Lancet Commission on Health and Climate Change, which emphasised that the response to climate change could be “the greatest global health opportunity of the 21st century”