Summary Zymoseptoria tritici is a filamentous fungus causing Septoria tritici blotch in wheat. The pathogen has a narrow host range and infections of grasses other than susceptible wheat are blocked early after stomatal penetration. During these abortive infections, the fungus shows a markedly different gene expression pattern. However, the underlying mechanisms causing differential gene expression during host and non‐host interactions are largely unknown, but likely include transcriptional regulators responsible for the onset of an infection programme in compatible hosts. MoCOD1, a member of the fungal Zn(II)2Cys6 transcription factor family, has been shown to directly affect pathogenicity in the rice blast pathogen Magnaporthe oryzae. Here, we analyse the role of the putative transcription factor Zt107320, a homologue of MoCOD1, during infection of compatible and incompatible hosts by Z. tritici. We show for the first time that Zt107320 is differentially expressed in host versus non‐host infections and that lower expression corresponds to an incompatible infection of non‐hosts. Applying reverse genetics approaches, we further show that Zt107320 regulates the dimorphic switch as well as the growth rate of Z. tritici and affects fungal cell wall composition in vitro. Moreover, ∆Zt107320 mutants showed reduced virulence during compatible infections of wheat. We conclude that Zt107320 directly influences pathogen fitness and propose that Zt107320 is involved in the regulation of growth processes and pathogenicity during infection.

formation 19 20 Word count: 6136 21 22 Zt107320 directly influences pathogen fitness and propose that Zt107320 regulates growth processes 38 and pathogenicity during infection. Our results suggest that this putative transcription factor is 39 involved in discriminating compatible and non-compatible infections. 40 41 2018), which may contribute to the genomic variation observed for Z. tritici (Grandaubert et al. 2017; 55 Hartmann et al. 2017). Under experimental conditions, the fungus has a narrow host range infecting 56 wheat and shows abortive infections on closely related non-host grass species like Triticum 57 monococcum (Jing et al. 2008) and Brachypodium distachyon (Kellner et al. 2014; O'Driscoll et al. 58 2015). However, the underlying determinants of host specialisation and host specificity of Z. tritici 59 are largely unknown. 60 A previous study comparing the expression profiles of Z. tritici between early infection (4 days post 61 infection) of the compatible host T. aestivum and the non-host B. distachyon revealed a set of 289 62genes that were similarly expressed in the two hosts, but differentially expressed compared to 63 growth in axenic culture (Kellner et al. 2014). These genes are likely crucial for Z. tritici during 64 stomatal penetration that occurs in same way in both hosts. However, 40 genes showed differential 65 expression between host and non-host infections (Kellner et al. 2014) and are possibly involved in 66 the discrimination of compatible and non-compatible host-pathogen interactions. The signalling and 67 157

The observed insect decline, which threatens agricultural productivity and ecosystem stability, calls for comprehensive international insect monitoring. Monitoring implementation demands standardisation and the integration of new and innovative methods. Therefore, we compared two quantitative butterfly survey methods – the commonly applied transect counts (or ‘Pollard walks’) and more extensive area-time counts. We evaluated the influence of the two methods on the estimation of biodiversity variables such as species richness and species abundance to examine whether they could be applied alternatively for the calculation of butterfly trend indicators. During 576 surveys we conducted 5-minute transect counts and 25-minute area-time counts simultaneously at 144 different sites in Western Austria. The estimated relative butterfly abundance of the two methods for 119 observed species showed a strong linear relationship. While we found 2.4 times more species per site with the more extensive area-time counts than with the transect counts, we also observed a strong correlation between estimates of local abundance (Pearson’s r = 0.85) and observed species richness (Pearson’s r = 0.81) based on the two methods. Area-time counts provide thorough assessments on a given location, enabling a close connection to specific habitat types and facilitating comparability with other plot-based biodiversity assessments. They are more suitable than transect counts when aiming to analyse the drivers of temporal and spatial variability in butterfly occurrence. Furthermore, area-time counts can be used synergistically for the calculation of international butterfly abundance trends (e.g., European butterfly indicators), as we found strong linear relationships for all applied indicators with both methods.

Ein Grundproblem der Klimawandelbildung ist die ,,Unsichtbarkeit“ von Klimawandel und seinen Folgen. Priorität im Projekt KlimaAlps ist, Klimawandelfolgen in ausgewählten Landschaftsräumen (,,KlimaTopen“) in der Projektregion Bayern und Österreich für jedermann/jederfrau in der Lebenswelt sichtbar zu machen. Darüber hinaus wird Lernen an ein authentisches Setting im KlimaTop angebunden. Durch Zusammenführung von KlimaTopen und Ausbildungsmodulen (KlimaModule) wird eine innovative Form von Klimawandel(aus)bildung entwickelt.