Fusarium graminearum forms mycotoxin producing infection structures on wheat

<p>Abstract</p> <p>Background</p> <p>The mycotoxin producing fungal pathogen <it>Fusarium graminearum </it>is the causal agent of Fusarium head blight (FHB) of small grain cereals in fields worldwide. Although <it>F. graminearum </it>is highly investigated by means of molecular genetics, detailed studies about hyphal development during initial infection stages are rare. In addition, the role of mycotoxins during initial infection stages of FHB is still unknown. Therefore, we investigated the infection strategy of the fungus on different floral organs of wheat (<it>Triticum aestivum </it>L.) under real time conditions by constitutive expression of the <it>dsRed </it>reporter gene in a <it>TRI5prom</it>::<it>GFP </it>mutant. Additionally, trichothecene induction during infection was visualised with a green fluorescent protein (GFP) coupled <it>TRI5 </it>promoter. A tissue specific infection pattern and <it>TRI5 </it>induction were tested by using different floral organs of wheat. Through combination of bioimaging and electron microscopy infection structures were identified and characterised. In addition, the role of trichothecene production for initial infection was elucidated by a Δ<it>TRI5</it>-<it>GFP </it>reporter strain.</p> <p>Results</p> <p>The present investigation demonstrates the formation of foot structures and compound appressoria by <it>F. graminearum</it>. All infection structures developed from epiphytic runner hyphae. Compound appressoria including lobate appressoria and infection cushions were observed on inoculated caryopses, paleas, lemmas, and glumes of susceptible and resistant wheat cultivars. A specific trichothecene induction in infection structures was demonstrated by different imaging techniques. Interestingly, a Δ<it>TRI5</it>-<it>GFP </it>mutant formed the same infection structures and exhibited a similar symptom development compared to the wild type and the <it>TRI5prom</it>::<it>GFP </it>mutant.</p> <p>Conclusions</p> <p>The different specialised infection structures of <it>F. graminearum </it>on wheat florets, as described in this study, indicate that the penetration strategy of this fungus is far more complex than postulated to date. We show that trichothecene biosynthesis is specifically induced in infection structures, but is neither necessary for their development nor for formation of primary symptoms on wheat.</p

Databases for Software Engineering Environments - The Goal has not yet been attained

We argue that, despite a substantial number of proposed and existing new database systems, a suitable database system for software development environments and especially process-centred environments does not yet exist. We do so by first reviewing and refining the requirements for such systems. We then review a number of available and archetypical database systems and show that they do not meet these requirements

Las ‘sectas’ protestantes y el espíritu del (anti-) imperialismo

Latin America, the United States of America, religion, and politics are ingredients of a brew with considerable explosive power. The four terms denote factors in a complex and, for the most part, violently intertwined relationship. Historically, this relation has been shaped primarily by the Protestant mission in Latin America and its Pan-American objectives. Yet, this mission now belongs to the past. The once American religiosity of the missionaries has taken different and more charismatic forms under the conflicting conditions of life in Latin America and today is shaped in particular by the class antagonisms of the subcontinent. However, this does not mean that some evangelical organizations do not continue to represent political interests of their Northern neighbor, or that vice versa,the political religiosity of the South does not contribute to ideological struggles in the United States, either through Liberation Theology in the 1980s, or today through the solidarity with Latin American migrants. The present book visualises the logic of the inter-American entanglements by tracing and interpreting exemplary developments and conflicts, framing the narrative plot between two important religious events in 1916 and 2016

Las ‘sectas’ protestantes y el espíritu del (anti-) imperialismo

Latin America, the United States of America, religion, and politics are ingredients of a brew with considerable explosive power. The four terms denote factors in a complex and, for the most part, violently intertwined relationship. Historically, this relation has been shaped primarily by the Protestant mission in Latin America and its Pan-American objectives. Yet, this mission now belongs to the past. The once American religiosity of the missionaries has taken different and more charismatic forms under the conflicting conditions of life in Latin America and today is shaped in particular by the class antagonisms of the subcontinent. However, this does not mean that some evangelical organizations do not continue to represent political interests of their Northern neighbor, or that vice versa,the political religiosity of the South does not contribute to ideological struggles in the United States, either through Liberation Theology in the 1980s, or today through the solidarity with Latin American migrants. The present book visualises the logic of the inter-American entanglements by tracing and interpreting exemplary developments and conflicts, framing the narrative plot between two important religious events in 1916 and 2016

Relativistic dust disks and the Wilson-Mathews approach

Treating problems in full general relativity is highly complex and frequently approximate methods are employed to simplify the solution. We present comparative solutions of a infinitesimally thin relativistic, stationary, rigidly rotating disk obtained using the full equations and the approximate approach suggested by Wilson & Mathews. We find that the Wilson-Mathews method has about the same accuracy as the first post-Newtonian approximation.Comment: 4 Pages, 5 eps-figures, uses revtex.sty. Submitted to PR

Investigating the effect of a nap following experimental trauma on analogue PTSD symptoms

Cognitive models assume that the incomplete integration of a traumatic experience into the autobiographical memory results in typical symptoms associated with post-traumatic stress disorder (PTSD) such as intrusive re-experiencing. Sleep supports the integration of new experiences into existing memory networks through memory consolidation. In fifty-six females, we investigated whether a 90-min daytime nap (n = 33) compared to a wake period (n = 23) after being exposed to an experimental trauma (i.e. a trauma film) prevents PTSD analogue symptoms. Intrusive memories were recorded for seven days using a diary, overall PTSD symptoms were assessed using the Impact of Event Scale (IES-R) and affective response to trauma cues were measured one week after experimental trauma. The two groups did not differ in any of the analogue PTSD symptoms. However, participants obtaining rapid eye movement (REM) sleep in the nap experienced less distressing intrusive memories. Moreover, the duration of REM sleep and slow wave activity was negatively correlated with analogue PTSD symptoms. Our findings suggest that even a short sleep period after experimental trauma can play a protective role in trauma memory formation but only if the nap contains REM sleep. Our data provide additional evidence for a critical role of REM sleep in PTSD development