TY - JOUR A1 - Berger, Susanne A1 - Ellersiek, Ulrike A1 - Steinmüller, Klaus T1 - Cyanobacteria contain a mitochrondrial complex I-homologous NADH-dehydrogenase N2 - Thylakoid and cytoplasmic membranes of the cyanobacterium Syncchocystis sp. PCC 6803 were purified by sucrose gradient centrifugation. Both membranes oxidize NADH in a rotenone-sensitive reaction. Antibodies prepared against psbG/ndhKand ndhJ fusion proteins detect the corresponding polypeptides in both membrane preparations. This demonstrates that a NADH-dehydrogenase, homologous to the mitochondrial NADHubiquinone-oxidoreductase (complex I of the respiratory chain) is present in cyanobacteria, The NADH-dehydrogenase can be solubilized with the detergent /-D-dodecylmaltoside. Sedimentation analysis of the solubilized enzyme on a sucrose gradient indicates that it is a multisubunit protein complex. KW - Respiratory chain KW - NADH-dehydrogenase KW - Cyanobacteria KW - Synechocystis 6803 Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31223 ER - TY - JOUR A1 - Berger, Susanne A1 - Ellersiek, Ulrike A1 - Kinzelt, Dagmar A1 - Steinmüller, Klaus T1 - Immunopurification of a subcomplex of the NAD(P)H-plastoquinone-oxidoreductase from the cyanobacterium Synechocystis sp. PCC6803 N2 - An antibody against the NDH-K subunit of the NAD(P)H-dehydrogenase from the cyanobacterium Synechocystis sp. PCC6803 was used to isolate a subcomplex ofthe enzyme from Triton X-lOO solubilized total membranes by immunoaffinity chromatography. The isolated subcomplex consisted of seven major polypeptides with molecular masses of 43, 27, 24, 21, 18, 14 and 7 kDa. The amino-terminal amino acid sequences of the polypeptides were determined. By comparing the sequences with the amino acid sequences deduced from DNA. three proteins were identified as NDH-H (43 kDa). NDH-K (27 kDa) and NDH-J (24 kDa). A fourth subunit (NDH-J, 21 kDa) was identified by Western blot analysis with an NDH-J antibody. KW - NAD(P)H-dehydrogenase KW - Cyanobacteria KW - Synechocystis sp. PCC6803 KW - NDH-H KW - NDH-I KW - NDH-J KW - NDH-K Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31249 ER - TY - JOUR A1 - Berger, Susanne A1 - Ellersiek, Ulrike A1 - Westhoff, Peter A1 - Steinmüller, Klaus T1 - Studies on the expression of NDH-H, a subunit of the NAD(P)H-plastoquinone-oxidoreductase of higher-plant chloroplasts N2 - The plastid genomes of higher plants contain eleven reading frames (ndhA-K) that are homologous to genes encoding subunits of the mitochondrial NADH-ubiquinone-oxidoreductase (complex I). The carboxyterminal end of the NDH-H subunit from rice (Oryza sativa L.) was expressed as a fusion protein in Escherichia coli and antibodies against the fusion protein were generated in rabbits. The antibody was used to study the expression of NDH-H, and the following results were obtained: (i) NDH-H is expressed in mono- and dicotyledonous plants, (ii) NDH-H is localized on the stroma lamellae of the thylakoid membrane and (iii) NDH-H is expressed in etioplasts. Together with the finding that two other ndh genes (ndhI and ndhK) are expressed in plastids, these results point to the existence of an NAD(P)H-plastoquinone-oxidoreductase on the thylakoid membrane. The possible function of the enzyme in plastids is discussed and it is suggested that it works in balancing the ATP/ADP and the NADPH/NADP ratios during changing external (i.e. light) or internal (i.e. ATP and NADPH demands of biosynthetic pathways of the plastid) conditions. KW - NAD(P)H-plastoquinone-oxidoreductase KW - ndhH gene KW - Plastid DNA Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31283 ER - TY - JOUR A1 - Stotz, Henrik U. A1 - Mueller, Stefan A1 - Zoeller, Maria A1 - Mueller, Martin J. A1 - Berger, Susanne T1 - TGA transcription factors and jasmonate-independent COI1 signalling regulate specific plant responses to reactive oxylipins JF - Journal of Experimental Botany N2 - Jasmonates and phytoprostanes are oxylipins that regulate stress responses and diverse physiological and developmental processes. 12-Oxo-phytodienoic acid (OPDA) and phytoprostanes are structurally related electrophilic cyclopentenones, which activate similar gene expression profiles that are for the most part different from the action of the cyclopentanone jasmonic acid (JA) and its biologically active amino acid conjugates. Whereas JA–isoleucine signals through binding to COI1, the bZIP transcription factors TGA2, TGA5, and TGA6 are involved in regulation of gene expression in response to phytoprostanes. Here root growth inhibition and target gene expression were compared after treatment with JA, OPDA, or phytoprostanes in mutants of the COI1/MYC2 pathway and in different TGA factor mutants. Inhibition of root growth by phytoprostanes was dependent on COI1 but independent of jasmonate biosynthesis. In contrast, phytoprostane-responsive gene expression was strongly dependent on TGA2, TGA5, and TGA6, but not dependent on COI1, MYC2, TGA1, and TGA4. Different mutant and overexpressing lines were used to determine individual contributions of TGA factors to cyclopentenone-responsive gene expression. Whereas OPDA-induced expression of the cytochrome P450 gene CYP81D11 was primarily regulated by TGA2 and TGA5, the glutathione S-transferase gene GST25 and the OPDA reductase gene OPR1 were regulated by TGA5 and TGA6, but less so by TGA2. These results support the model that phytoprostanes and OPDA regulate differently (i) growth responses, which are COI1 dependent but jasmonate independent; and (ii) lipid stress responses, which are strongly dependent on TGA2, TGA5, and TGA6. Identification of molecular components in cyclopentenone signalling provides an insight into novel oxylipin signal transduction pathways. KW - lipid signaling KW - reactive electrophile oxylipins KW - detoxification KW - class II TGA factors KW - biotic and abiotic stress KW - arabidopsis thaliana Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-132318 VL - 64 IS - 4 ER - TY - JOUR A1 - Münch, Miriam A1 - Hsin, Chih-Hsuan A1 - Ferber, Elena A1 - Berger, Susanne A1 - Müller, Martin J. T1 - Reactive electrophilic oxylipins trigger a heat stress-like response through HSFA1 transcription factors JF - Journal of Experimental Botany N2 - Electrophilic oxylipins trigger a heat-shock-like response in the absence of heat through the canonical heat-shock transcription factor A1, thereby helping to cope with stresses associated with protein damage.Abiotic and biotic stresses are often characterized by an induction of reactive electrophile species (RES) such as the jasmonate 12-oxo-phytodienoic acid (OPDA) or the structurally related phytoprostanes. Previously, RES oxylipins have been shown massively to induce heat-shock-response (HSR) genes including HSP101 chaperones. Moreover, jasmonates have been reported to play a role in basal thermotolerance. We show that representative HSR marker genes are strongly induced by RES oxylipins through the four master regulator transcription factors HSFA1a, b, d, and e essential for short-term adaptation to heat stress in Arabidopsis. When compared with Arabidopsis seedlings treated at the optimal acclimation temperature of 37 A degrees C, the exogenous application of RES oxylipins at 20 A degrees C induced a much weaker induction of HSP101 at both the gene and protein expression levels which, however, was not sufficient to confer short-term acquired thermotolerance. Moreover, jasmonate-deficient mutant lines displayed a wild-type-like HSR and were not compromised in acquiring thermotolerance. Hence, the OPDA- and RES oxylipin-induced HSR is not sufficient to protect seedlings from severe heat stress but may help plants to cope better with stresses associated with protein unfolding by inducing a battery of chaperones in the absence of heat. KW - arabidopsis-thaliana KW - shock response KW - gene-expression KW - model KW - acquired thermotolerance KW - 12-oxo-phytodienoic acid KW - thermotolerance KW - plants KW - detoxification KW - acquisition KW - activation KW - heat stress KW - jasmonates KW - phytoprostanes KW - reactive electrophilic species KW - unfolded protein response Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186766 VL - 67 IS - 21 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 - Schieferle, Sebastian A1 - Tappe, Beeke A1 - Korte, Pamela A1 - Mueller, Martin J. A1 - Berger, Susanne T1 - Pathogens and Elicitors Induce Local and Systemic Changes in Triacylglycerol Metabolism in Roots and in Leaves of Arabidopsis thaliana JF - Biology N2 - Simple Summary Abiotic and biotic stress conditions result in profound changes in plant lipid metabolism. Vegetable oil consists of triacylglycerols, which are important energy and carbon storage compounds in seeds of various plant species. These compounds are also present in vegetative tissue, and levels have been reported to increase with different abiotic stresses in leaves. This work shows that triacylglycerols accumulate in roots and in distal, non-treated leaves upon treatment with a fungal pathogen or lipopolysaccharide (a common bacterial-derived elicitor in animals and plants). Treatment of leaves with a bacterial pathogen or a bacterial effector molecule results in triacylglycerol accumulation in leaves, but not systemically in roots. These results suggest that elicitor molecules are sufficient to induce an increase in triacylglycerol levels, and that unidirectional long-distance signaling from roots to leaves is involved in pathogen and elicitor-induced triacylglycerol accumulation. Abstract Interaction of plants with the environment affects lipid metabolism. Changes in the pattern of phospholipids have been reported in response to abiotic stress, particularly accumulation of triacylglycerols, but less is known about the alteration of lipid metabolism in response to biotic stress and leaves have been more intensively studied than roots. This work investigates the levels of lipids in roots as well as leaves of Arabidopsis thaliana in response to pathogens and elicitor molecules by UPLC-TOF-MS. Triacylglycerol levels increased in roots and systemically in leaves upon treatment of roots with the fungus Verticillium longisporum. Upon spray infection of leaves with the bacterial pathogen Pseudomonas syringae, triacylglycerols accumulated locally in leaves but not in roots. Treatment of roots with a bacterial lipopolysaccharide elicitor induced a strong triacylglycerol accumulation in roots and leaves. Induction of the expression of the bacterial effector AVRRPM1 resulted in a dramatic increase of triacylglycerol levels in leaves, indicating that elicitor molecules are sufficient to induce accumulation of triacylglycerols. These results give insight into local and systemic changes to lipid metabolism in roots and leaves in response to biotic stresses. KW - triacylglycerols KW - membrane remodeling KW - pathogens KW - elicitors KW - effectors Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-246198 SN - 2079-7737 VL - 10 IS - 9 ER -