TY - JOUR ID - 2247 TI - Metabolic profiling of oxylipins upon sorbitol treatment in barley leaves JO - Biochem. Soc. Trans. PY - 2001 SP - 861-862 AU - Weichert, H. AU - Kohlmann, M. AU - Wasternack, C. AU - Feussner, I. AU - VL - 28 UR - DO - 10.1042/bst0280861 AB - In barley leaves 13-lipoxygenases (LOXs) are induced by salicylate and jasmonate. Here, we analyse by metabolic profiling the accumulation of oxylipins upon sorbitol treatment. Although 13-LOX-derived products are formed and specifically directed into the reductase branch of the LOX pathway, accumulation is much later than in the cases of salicylate and jasmonate treatment. In addition, under these conditions only the accumulation of jasmonates as additional products of the LOX pathway has been found. KW - NOT SETA2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 2294 TI - Formation of 4-hydroxy-2-alkenals in barley leaves JO - Biochem. Soc. Trans. PY - 2000 SP - 850-851 AU - Weichert, H. AU - Kolbe, A. AU - Wasternack, C. AU - Feussner, I. AU - VL - 28 UR - DO - 10.1042/bst0280850 AB - In barley leaves 13-lipoxygenases are induced by jasmonates. This leads to induction of lipid peroxidation. Here we show by in vitro studies that these processes may further lead to autoxidative formation of (2E)-4-hydroxy-2-hexenal from (3Z)-hexenal. KW - NOT SETA2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 2391 TI - Induction of a new Lipoxygenase Form in Cucumber Leaves by Salicylic Acid or 2,6-Dichloroisonicotinic Acid JO - Bot. Acta PY - 1997 SP - 101-108 AU - Feussner, I. AU - Fritz, I. G. AU - Hause, B. AU - Ullrich, W. R. AU - Wasternack, C. AU - VL - 110 UR - DO - 10.1111/j.1438-8677.1997.tb00616.x AB - Changes in lipoxygenase (LOX) protein pattern and/or activity were investigated in relation to acquired resistance of cucumber (Cucumis sativus L.) leaves against two powdery mildews, Sphaerotheca fuliginea (Schlecht) Salmon and Erysiphe cichoracearum DC et Merat. Acquired resistance was established by spraying leaves with salicylic acid (SA) or 2,6‐dichloroisonicotinic acid (INA) and estimated in whole plants by infested leaf area compared to control plants. SA was more effective than INA. According to Western blots, untreated cucumber leaves contained a 97 kDa LOX form, which remained unchanged for up to 48 h after pathogen inoculation. Upon treatment with SA alone for 24 h or with INA plus pathogen, an additional 95 kDa LOX form appeared which had an isoelectric point in the alkaline range. For the induction of this form, a threshold concentration of 1 mM SA was required, higher SA concentrations did not change LOX‐95 expression which remained similar between 24 h and 96 h but further increased upon mildew inoculation. Phloem exudates contained only the LOX‐97 form, in intercellular washing fluid no LOX was detected. dichloroisonicotinic localization revealed LOX protein in the cytosol of the mesophyll cells without differences between the forms. KW - NOT SETA2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER - TY - JOUR ID - 2401 TI - Nuclear Location of a Diadenosine 5′,5′”-P1,P4Tetraphosphate (Ap4A) Hydrolase in Tomato Cells Grown in Suspension Cultures JO - Bot. Acta PY - 1997 SP - 452-457 AU - Hause, B. AU - Feussner, K. AU - Wasternack, C. AU - VL - 110 UR - DO - 10.1111/j.1438-8677.1997.tb00662.x AB - Diadenosine 5′,5′”‐P1,P4‐tetraphosphate (Ap4A) cleaving enzymes are assumed to regulate intracellular levels of Ap4A, a compound known to affect cell proliferation and stress responses. From plants an Ap4A hydrolase was recently purified using tomato cells grown in suspension. It was partially sequenced and a peptide antibody was prepared (Feussner et al., 1996). Using this polyclonal monospecific antibody, an abundant nuclear location of Ap4A hydrolase in 4‐day‐old cells of atomato cell suspension culture is demonstrated here by means of immunocytochemical techniques using FITC (fluorescein‐5‐isothiocyanate) labeled secondary antibodies. The microscopic analysis of the occurrence of Ap4A hydrolase performed for different stages of the cell cycle visualized by parallel DAPI (4,6‐diamidino‐2‐phenylindole) staining revealed that the protein accumulates within nuclei of cells in the interphase, but is absent in the nucleus as well as cytoplasm during all stages of mitosis. This first intracellular localization of an Ap4A degrading enzyme within the nucleus and its pattern of appearance during the cell cycle is discussed in relation to the suggested role of Ap4A in triggering DNA synthesis and cell proliferation. KW - NOT SETA2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER - TY - JOUR ID - 2463 TI - Resistance in barley against the powdery mildew fungus (Erysiphe graminis f.sp.hordei) is not associated with enhanced levels of endogenous jasmonates JO - Eur. J. Plant Pathol. PY - 1995 SP - 319-332 AU - Kogel, K.-H. AU - Ortel, B. AU - Jarosch, B. AU - Atzorn, R. AU - Schiffer, R. AU - Wasternack, C. AU - VL - 101 UR - DO - 10.1007/BF01874788 AB - Onset of acquired resistance of barley (Hordeum vulgare) chemically induced by 2,6-dichloroisonicotinic acid (DCINA) correlated with the accumulation of mRNA homologous to cDNA pHvJ256 which codes for a soluble leaf-thionin with a Mr. of 6 kDa [Wasternacket al., 1994a]. In the present work, we extend this finding by showing that the thionin transcript also accumulated following treatment of barley with the resistance-inducing compounds 3,5-dichlorosalicylic acid (DCSA), salicylic acid (SA), and an extract fromBacillus subtilis. The polypeptide showed antifungal activity against the biotrophic cereal pathogensErysiphe graminis f.sp.hordei andPuccinia graminis f.sp.tritici which may indicate a possible role in the mechanism of acquired resistance in barley. A thionin transcript hybridizing to pHvJ256 accumulated also in response to application of jasmonates, or treatments that elevated endogenous amounts of the plant growth substance, pointing to the possibility that signaling mediating defense responses in barley involves jasmonates. However, a topical spray application of jasmonic acid (JA) or jasmonate methyl ester (JM) did not protect barley leaves against infection byE. graminis. Performing a kinetic analysis by an enzyme immunoassay specific for (−)-JA, (−)-JM, and its amino acid conjugates, accumulation of jasmonates was detected in osmotically stressed barley but not at the onset of chemically induced or genetically based resistance governed by the powdery mildew resistance genesMlg, Mla 12, ormlo 5. Furthermore, the jasmonate-inducible proteins JIP-23 and JIP-60 were strongly induced following JM- but not DCINA-treatment or inoculation withE. graminis. Hence, in barley, no indications were found in favour for the previously proposed model of a lipid-based signaling pathway via jasmonates mediating expression of resistance in plants against pathogens. KW - NOT SETA2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 2478 TI - Intracellular Localization of Jasmonate-Induced Proteins in Barley Leaves JO - Bot. Acta PY - 1994 SP - 333-341 AU - Hause, B. AU - zur Nieden, U. AU - Lehmann, J. AU - Wasternack, C. AU - Parthier, B. AU - VL - 107 UR - DO - 10.1111/j.1438-8677.1994.tb00804.x AB - The plant growth substance jasmonic acid and its methyl ester (JA‐Me) induce a set of proteins (jasmonate‐induced proteins, JIPs) when applied to leaf segments of barley (Hordeum vulgare L. cv. Salome). Most of these JIPs could be localized within different cell compartments by using a combination of biochemical and histochemical methods. Isolation and purification of various cell organelles of barley mesophyll cells, the separation of their proteins by one‐dimensional polyacrylamide gel electrophoresis and the identification of the major abundant JIPs by Western blot analysis, as well as the immuno‐gold labelling of JIPs in ultrathin sections were performed to localize JIPs intracellularly. JIP‐23 was found to be in vacuoles, peroxisomes, and in the granular parts of the nucleus as well as within the cytoplasm; JIP‐37 was detected in vacuoles and in the nucleoplasm; JIP‐66 is a cytosolic protein. Some less abundant JIPs were also localized within different cell compartments: JIP‐100 was found within the stromal fraction of chloroplasts; JIP‐70 is present in the peroxisome and the nucleus; JIP‐50 and JIP‐6 accumulate in vacuoles. The location of JIP‐66 and JIP‐6 confirms their possible physiological role deduced from molecular analysis of their cDNA. KW - NOT SETA2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER -