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Publikationen - Molekulare Signalverarbeitung

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Publikation

Wasternack, C.; Kombrink, E. Jasmonates: Structural Requirements for Lipid-Derived Signals Active in Plant Stress Responses and Development ACS Chem Biol 5, 63-77, (2010) DOI: 10.1021/cb900269u

Jasmonates are lipid-derived signals that mediate plant stress responses and development processes. Enzymes participating in biosynthesis of jasmonic acid (JA) (1, 2) and components of JA signaling have been extensively characterized by biochemical and molecular-genetic tools. Mutants of Arabidopsis and tomato have helped to define the pathway for synthesis of jasmonoyl-isoleucine (JA-Ile), the active form of JA, and to identify the F-box protein COI1 as central regulatory unit. However, details of the molecular mechanism of JA signaling have only recently been unraveled by the discovery of JAZ proteins that function in transcriptional repression. The emerging picture of JA perception and signaling cascade implies the SCFCOI1 complex operating as E3 ubiquitin ligase that upon binding of JA-Ile targets JAZ repressors for degradation by the 26S-proteasome pathway, thereby allowing the transcription factor MYC2 to activate gene expression. The fact that only one particular stereoisomer, (+)-7-iso-JA-l-Ile (4), shows high biological activity suggests that epimerization between active and inactive diastereomers could be a mechanism for turning JA signaling on or off. The recent demonstration that COI1 directly binds (+)-7-iso-JA-l-Ile (4) and thus functions as JA receptor revealed that formation of the ternary complex COI1-JA-Ile-JAZ is an ordered process. The pronounced differences in biological activity of JA stereoisomers also imply strict stereospecific control of product formation along the JA biosynthetic pathway. The pathway of JA biosynthesis has been unraveled, and most of the participating enzymes are well-characterized. For key enzymes of JA biosynthesis the crystal structures have been established, allowing insight into the mechanisms of catalysis and modes of substrate binding that lead to formation of stereospecific products.
Publikation

Delker, C.; Stenzel, I.; Hause, B.; Miersch, O.; Feussner, I.; Wasternack, C. Jasmonate Biosynthesis in Arabidopsis thaliana - Enzymes, Products, Regulation Plant Biol. 8, 297-306, (2006) DOI: 10.1055/s-2006-923935

Among the plant hormones jasmonic acid and related derivatives are known to mediate stress responses and several developmental processes. Biosynthesis, regulation, and metabolism of jasmonic acid in Arabidopsis thaliana are reviewed, including properties of mutants of jasmonate biosynthesis. The individual signalling properties of several jasmonates are described.
Publikation

Wasternack, C.; Stenzel, I.; Hause, B.; Hause, G.; Kutter, C.; Maucher, H.; Neumerkel, J.; Feussner, I.; Miersch, O. The wound response in tomato - Role of jasmonic acid J. Plant Physiol 163, 297-306 , (2006) DOI: 10.1016/j.jplph.2005.10.014

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Publikation

Schilling, S.; Manhart, S.; Hoffmann, T.; Ludwig, H.-H.; Wasternack, C.; Demuth, H.-U. Substrate specificity of glutaminyl cyclases from plants and animals Biol. Chem. 384, 1583-1592, (2003)

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Publikation

Miersch, O.; Wasternack, C. Octadecanoid and jasmonate signaling in tomato leaves (<EM>Lycopersicon esculentum</EM> Mill.): Endogenous jasmonates do not induce jasmonate biosynthesis Biol. Chem. 381, 715-722, (2000)

Jasmonates and their precursors, the octadecanoids, are signals in stress-induced alteration of gene expression. Several mRNAs coding for enzymes of jasmonic acid (JA) biosynthesis are up-regulated upon JA treatment or endogenous rise of JA level. Here we inspected the positive feed back of endogenous JA on JA formation as well as its beta-oxidation steps. JA responsive gene expression was recorded in terms of proteinase inhibitor2 (pin2) mRNA accumulation. JA formed upon treatment of tomato (Lycopersicon esculentum cv. Moneymaker) leaves with JA derivatives carrying different length of the carboxylic acid side chain was quantified by gas chromatography-mass spectrometry (GC-MS). The data reveal that beta-oxidation of the side chain occurs up to a butyric acid moiety. The amount of JA formed from side-chain modified JA derivatives, correlated with pin2-mRNA accumulation. JA derivatives with a carboxylic side chain of 3, 5 or 7 carbon atoms were unable to form JA and to express on pin2, whereas even numbered derivatives were active. After treatment of tomato leaves with (10-2H)-(-)-12-oxophytoenoic acid, (4-2H)-(-)-JA and its methyl ester were formed and could be quantified separately from the endogenously unlabeled JA pool by GC-MS analysis via isotopic discrimination. The level of 8 nmol per g f.w. JA and its methyl ester originated exclusively from labeled 12-oxophytoenic acid. This and further data indicate that endogenous synthesis of the JA precursor 12-oxophytodienoic acid as well as of JA and its methyl ester are not induced in tomato leaves, suggesting that positive feedback in JA biosynthesis does not function in vivo.
Bücher und Buchkapitel

Feussner, I.; Balkenhohl, T.; Porzel, A.; Kühn, H.; Wasternack, C. Structural elucidation of oxygenated triacylglycerols in cucumber and sunflower cotyledons (Schreier, P., Herderich, M., Humpf, H.-U., Schwab, W.). P. Vieweg, Wiesbaden 57-58, (1998)

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Bücher und Buchkapitel

Kohlmann, M.; Kuntzsch, A.; Wasternack, C.; Feussner, I. Effect of jasmonic acid methyl ester on enzymes of the lipoxygenase pathway in barley leaves (Schreier, P., Herderich, M., Humpf, H.-U., Schwab, W.). P. Vieweg, Wiesbaden 339-340, (1998)

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Publikation

Kogel, K.-H.; Ortel, B.; Jarosch, B.; Atzorn, R.; Schiffer, R.; Wasternack, C. Resistance in barley against the powdery mildew fungus (<EM>Erysiphe graminis</EM> f. sp. hordei) is not associated with enhanced levels of endogenous jasmonates Eur. J. Plant Pathol. 101, 319-332, (1995)

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