TY - JOUR A1 - Thurow, Corinna A1 - Krischke, Markus A1 - Mueller, Martin J. A1 - Gatz, Christiane T1 - Induction of jasmonoyl-isoleucine (JA-Ile)-dependent JASMONATE ZIM-DOMAIN (JAZ) genes in NaCl-treated Arabidopsis thaliana roots can occur at very low JA-Ile levels and in the absence of the JA/JA-Ile transporter JAT1/AtABCG16 JF - Plants N2 - The plant hormone jasmonoyl-isoleucine (JA-Ile) is an important regulator of plant growth and defense in response to various biotic and abiotic stress cues. Under our experimental conditions, JA-Ile levels increased approximately seven-fold in NaCl-treated Arabidopsis thaliana roots. Although these levels were around 1000-fold lower than in wounded leaves, genes of the JA-Ile signaling pathway were induced by a factor of 100 or more. Induction was severely compromised in plants lacking the JA-Ile receptor CORONATINE INSENSITIVE 1 or enzymes required for JA-Ile biosynthesis. To explain efficient gene expression at very low JA-Ile levels, we hypothesized that salt-induced expression of the JA/JA-Ile transporter JAT1/AtABCG16 would lead to increased nuclear levels of JA-Ile. However, mutant plants with different jat1 alleles were similar to wild-type ones with respect to salt-induced gene expression. The mechanism that allows COI1-dependent gene expression at very low JA-Ile levels remains to be elucidated. KW - allene oxide synthase KW - CORONATINE INSENSITIVE 1 KW - jasmonoyl-isoleucine KW - JA/JA-Ile transport protein JAT1 KW - roots KW - salt Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-219382 SN - 2223-7747 VL - 9 IS - 12 ER - TY - JOUR A1 - Krauss, Jochen A1 - Vikuk, Veronika A1 - Young, Carolyn A. A1 - Krischke, Markus A1 - Mueller, Martin J. A1 - Baerenfaller, Katja T1 - Correction: Krauss, J., et al. Epichloë endophyte infection rates and alkaloid content in commercially available grass seed mixtures in Europe. Microorganisms 2020, 8, 498 JF - Microorganisms N2 - No abstract available. KW - Epichloë KW - endophyte Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-216254 SN - 2076-2607 VL - 8 IS - 10 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 - Ferber, Elena A1 - Gerhards, Julian A1 - Sauer, Miriam A1 - Krischke, Markus A1 - Dittrich, Marcus T. A1 - Müller, Tobias A1 - Berger, Susanne A1 - Fekete, Agnes A1 - Mueller, Martin J. T1 - Chemical Priming by Isothiocyanates Protects Against Intoxication by Products of the Mustard Oil Bomb JF - Frontiers in Plant Science N2 - In Brassicaceae, tissue damage triggers the mustard oil bomb i.e., activates the degradation of glucosinolates by myrosinases leading to a rapid accumulation of isothiocyanates at the site of damage. Isothiocyanates are reactive electrophilic species (RES) known to covalently bind to thiols in proteins and glutathione, a process that is not only toxic to herbivores and microbes but can also cause cell death of healthy plant tissues. Previously, it has been shown that subtoxic isothiocyanate concentrations can induce transcriptional reprogramming in intact plant cells. Glutathione depletion by RES leading to breakdown of the redox potential has been proposed as a central and common RES signal transduction mechanism. Using transcriptome analyses, we show that after exposure of Arabidopsis seedlings (grown in liquid culture) to subtoxic concentrations of sulforaphane hundreds of genes were regulated without depletion of the cellular glutathione pool. Heat shock genes were among the most highly up-regulated genes and this response was found to be dependent on the canonical heat shock factors A1 (HSFA1). HSFA1-deficient plants were more sensitive to isothiocyanates than wild type plants. Moreover, pretreatment of Arabidopsis seedlings with subtoxic concentrations of isothiocyanates increased resistance against exposure to toxic levels of isothiocyanates and, hence, may reduce the autotoxicity of the mustard oil bomb by inducing cell protection mechanisms. KW - autotoxicity KW - heat shock response KW - isothiocyanates KW - mustard oil bomb KW - reactive electrophilic species KW - redox homeostasis KW - sulforaphane Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-207104 SN - 1664-462X VL - 11 ER - TY - JOUR A1 - Krauss, Jochen A1 - Vikuk, Veronika A1 - Young, Carolyn A. A1 - Krischke, Markus A1 - Mueller, Martin J. A1 - Baerenfaller, Katja T1 - Epichloë endophyte infection rates and alkaloid content in commercially available grass seed mixtures in Europe JF - Microorganisms N2 - Fungal endophytes of the genus Epichloë live symbiotically in cool season grass species and can produce alkaloids toxic to insects and vertebrates, yet reports of intoxication of grazing animals have been rare in Europe in contrast to overseas. However, due to the beneficial resistance traits observed in Epichloë infected grasses, the inclusion of Epichloë in seed mixtures might become increasingly advantageous. Despite the toxicity of fungal alkaloids, European seed mixtures are rarely tested for Epichloë infection and their infection status is unknown for consumers. In this study, we tested 24 commercially available seed mixtures for their infection rates with Epichloë endophytes and measured the concentrations of the alkaloids ergovaline, lolitrem B, paxilline, and peramine. We detected Epichloë infections in six seed mixtures, and four contained vertebrate and insect toxic alkaloids typical for Epichloë festucae var. lolii infecting Lolium perenne. As Epichloë infected seed mixtures can harm livestock, when infected grasses become dominant in the seeded grasslands, we recommend seed producers to test and communicate Epichloë infection status or avoiding Epichloë infected seed mixtures. KW - Epichloë spp. KW - grass endophytes KW - cool-season grass species KW - infection rates KW - alkaloids KW - toxicity KW - livestock KW - horses KW - Lolium perenne KW - perennial ryegrass Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-203323 SN - 2076-2607 VL - 8 IS - 4 ER -