TY - JOUR A1 - König, Julia A1 - Guerreiro, Marco Alexandre A1 - Peršoh, Derek A1 - Begerow, Dominik A1 - Krauss, Jochen T1 - Knowing your neighbourhood - the effects of Epichloë endophytes on foliar fungal assemblages in perennial ryegrass in dependence of season and land-use intensity JF - PeerJ N2 - Epichloë endophytes associated with cool-season grass species can protect their hosts from herbivory and can suppress mycorrhizal colonization of the hosts’ roots. However, little is known about whether or not Epichloë endophyte infection can also change the foliar fungal assemblages of the host. We tested 52 grassland study sites along a land-use intensity gradient in three study regions over two seasons (spring vs. summer) to determine whether Epichloë infection of the host grass Lolium perenne changes the fungal community structure in leaves. Foliar fungal communities were assessed by Next Generation Sequencing of the ITS rRNA gene region. Fungal community structure was strongly affected by study region and season in our study, while land-use intensity and infection with Epichloë endophytes had no significant effects. We conclude that effects on non-systemic endophytes resulting from land use practices and Epichloë infection reported in other studies were masked by local and seasonal variability in this study’s grassland sites. KW - endophytic fungi KW - symbiosis KW - Lolium perenne KW - land use KW - fungus-plant interaction KW - foliar fungal community KW - Epichloë Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176814 VL - 6 IS - e4660 ER - TY - JOUR A1 - Beer, Katharina A1 - Joschinski, Jens A1 - Sastre, Alazne Arrazola A1 - Krauss, Jochen A1 - Helfrich-Förster, Charlotte T1 - A damping circadian clock drives weak oscillations in metabolism and locomotor activity of aphids (Acyrthosiphon pisum) JF - Scientific Reports N2 - Timing seasonal events, like reproduction or diapause, is crucial for the survival of many species. Global change causes phenologies worldwide to shift, which requires a mechanistic explanation of seasonal time measurement. Day length (photoperiod) is a reliable indicator of winter arrival, but it remains unclear how exactly species measure day length. A reference for time of day could be provided by a circadian clock, by an hourglass clock, or, as some newer models suggest, by a damped circadian clock. However, damping of clock outputs has so far been rarely observed. To study putative clock outputs of Acyrthosiphon pisum aphids, we raised individual nymphs on coloured artificial diet, and measured rhythms in metabolic activity in light-dark illumination cycles of 16:08 hours (LD) and constant conditions (DD). In addition, we kept individuals in a novel monitoring setup and measured locomotor activity. We found that A. pisum is day-active in LD, potentially with a bimodal distribution. In constant darkness rhythmicity of locomotor behaviour persisted in some individuals, but patterns were mostly complex with several predominant periods. Metabolic activity, on the other hand, damped quickly. A damped circadian clock, potentially driven by multiple oscillator populations, is the most likely explanation of our results. KW - circadian mechanisms KW - behavioural ecology KW - damped circadian clock KW - Acyrthosiphon pisum Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170020 VL - 7 IS - 14906 ER - TY - JOUR A1 - Vikuk, Veronika A1 - Fuchs, Benjamin A1 - Krischke, Markus A1 - Mueller, Martin J. A1 - Rueb, Selina A1 - Krauss, Jochen T1 - Alkaloid Concentrations of Lolium perenne Infected with Epichloë festucae var. lolii with Different Detection Methods—A Re-Evaluation of Intoxication Risk in Germany? JF - Journal of Fungi N2 - Mycotoxins in agriculturally used plants can cause intoxication in animals and can lead to severe financial losses for farmers. The endophytic fungus Epichloë festucae var. lolii living symbiotically within the cool season grass species Lolium perenne can produce vertebrate and invertebrate toxic alkaloids. Hence, an exact quantitation of alkaloid concentrations is essential to determine intoxication risk for animals. Many studies use different methods to detect alkaloid concentrations, which complicates the comparability. In this study, we showed that alkaloid concentrations of individual plants exceeded toxicity thresholds on real world grasslands in Germany, but not on the population level. Alkaloid concentrations on five German grasslands with high alkaloid levels peaked in summer but were also below toxicity thresholds on population level. Furthermore, we showed that alkaloid concentrations follow the same seasonal trend, regardless of whether plant fresh or dry weight was used, in the field and in a common garden study. However, alkaloid concentrations were around three times higher when detected with dry weight. Finally, we showed that alkaloid concentrations can additionally be biased to different alkaloid detection methods. We highlight that toxicity risks should be analyzed using plant dry weight, but concentration trends of fresh weight are reliable. KW - Epichloë KW - Lolium perenne KW - toxicity KW - grasslands KW - HPLC/UPLC methods KW - endophyte KW - plant fresh/dry weight KW - alkaloid detection methods KW - mycotoxins KW - phenology Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-213171 SN - 2309-608X VL - 6 IS - 3 ER - TY - JOUR A1 - Le Provost, Gaëtane A1 - Thiele, Jan A1 - Westphal, Catrin A1 - Penone, Caterina A1 - Allan, Eric A1 - Neyret, Margot A1 - van der Plas, Fons A1 - Ayasse, Manfred A1 - Bardgett, Richard D. A1 - Birkhofer, Klaus A1 - Boch, Steffen A1 - Bonkowski, Michael A1 - Buscot, Francois A1 - Feldhaar, Heike A1 - Gaulton, Rachel A1 - Goldmann, Kezia A1 - Gossner, Martin M. A1 - Klaus, Valentin H. A1 - Kleinebecker, Till A1 - Krauss, Jochen A1 - Renner, Swen A1 - Scherreiks, Pascal A1 - Sikorski, Johannes A1 - Baulechner, Dennis A1 - Blüthgen, Nico A1 - Bolliger, Ralph A1 - Börschig, Carmen A1 - Busch, Verena A1 - Chisté, Melanie A1 - Fiore-Donno, Anna Maria A1 - Fischer, Markus A1 - Arndt, Hartmut A1 - Hoelzel, Norbert A1 - John, Katharina A1 - Jung, Kirsten A1 - Lange, Markus A1 - Marzini, Carlo A1 - Overmann, Jörg A1 - Paŝalić, Esther A1 - Perović, David J. A1 - Prati, Daniel A1 - Schäfer, Deborah A1 - Schöning, Ingo A1 - Schrumpf, Marion A1 - Sonnemann, Ilja A1 - Steffan-Dewenter, Ingolf A1 - Tschapka, Marco A1 - Türke, Manfred A1 - Vogt, Juliane A1 - Wehner, Katja A1 - Weiner, Christiane A1 - Weisser, Wolfgang A1 - Wells, Konstans A1 - Werner, Michael A1 - Wolters, Volkmar A1 - Wubet, Tesfaye A1 - Wurst, Susanne A1 - Zaitsev, Andrey S. A1 - Manning, Peter T1 - Contrasting responses of above- and belowground diversity to multiple components of land-use intensity JF - Nature Communications N2 - Land-use intensification is a major driver of biodiversity loss. However, understanding how different components of land use drive biodiversity loss requires the investigation of multiple trophic levels across spatial scales. Using data from 150 agricultural grasslands in central Europe, we assess the influence of multiple components of local- and landscape-level land use on more than 4,000 above- and belowground taxa, spanning 20 trophic groups. Plot-level land-use intensity is strongly and negatively associated with aboveground trophic groups, but positively or not associated with belowground trophic groups. Meanwhile, both above- and belowground trophic groups respond to landscape-level land use, but to different drivers: aboveground diversity of grasslands is promoted by diverse surrounding land-cover, while belowground diversity is positively related to a high permanent forest cover in the surrounding landscape. These results highlight a role of landscape-level land use in shaping belowground communities, and suggest that revised agroecosystem management strategies are needed to conserve whole-ecosystem biodiversity. KW - biodiversity KW - community ecology KW - grassland ecology Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-371552 VL - 12 ER -