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579 results on '"Wasternack, Claus"'

118. Plant Signal Transduction

Author

Scheel, Dierk and Wasternack, Claus

Subjects
Plant Signal Transduction (Book), Biological sciences
Published
2002

122. Multiple Hormones Act Sequentially to Mediate a Susceptible Tomato Pathogen Defense Response1

Author

O'Donnell, Philip J., Schmelz, Eric, Block, Anna, Miersch, Otto, Wasternack, Claus, Jones, Jeffrey B., and Klee, Harry J.

Subjects
Virulence, food and beverages, Cyclopentanes, Ethylenes, Plants, Genetically Modified, Xanthomonas campestris, Immunity, Innate, Solanum lycopersicum, Plant Growth Regulators, Drug Interactions, Oxylipins, Salicylic Acid, Research Article, Plant Diseases, Signal Transduction
Abstract

Phytohormones regulate plant responses to a wide range of biotic and abiotic stresses. How a limited number of hormones differentially mediate individual stress responses is not understood. We have used one such response, the compatible interaction of tomato (Lycopersicon esculentum) and Xanthomonas campestris pv vesicatoria (Xcv), to examine the interactions of jasmonic acid (JA), ethylene, and salicylic acid (SA). The role of JA was assessed using an antisense allene oxide cyclase transgenic line and the def1 mutant to suppress Xcv-induced biosynthesis of jasmonates. Xcv growth was limited in these lines as was subsequent disease symptom development. No increase in JA was detected before the onset of terminal necrosis. The lack of a detectable increase in JA may indicate that an oxylipin other than JA regulates basal resistance and symptom proliferation. Alternatively, there may be an increase in sensitivity to JA or related compounds following infection. Hormone measurements showed that the oxylipin signal must precede subsequent increases in ethylene and SA accumulation. Tomato thus actively regulates the Xcv-induced disease response via the sequential action of at least three hormones, promoting expansive cell death of its own tissue. This sequential action of jasmonate, ethylene, and SA in disease symptom development is different from the hormone interactions observed in many other plant-pathogen interactions.

Published
2003

124. Octadecanoid-Derived Alteration of Gene Expression and the 'Oxylipin Signature' in Stressed Barley Leaves. Implications for Different Signaling Pathways1

Author

Kramell, Robert, Miersch, Otto, Atzorn, Rainer, Parthier, Benno, and Wasternack, Claus

Subjects
Cyclopropanes, Plant Leaves, Linoleic Acids, Gene Expression Regulation, Plant, Hordeum, Gas Chromatography-Mass Spectrometry, Research Article, Signal Transduction
Abstract

Stress-induced gene expression in barley (Hordeum vulgare cv Salome) leaves has been correlated with temporally changing levels of octadecanoids and jasmonates, quantified by means of gas chromatography/mass spectrometry-single ion monitoring. Application of sorbitol-induced stress led to a low and transient rise of jasmonic acid (JA), its precursor 12-oxophytodienoic acid (OPDA), and the methyl esters JAME and OPDAME, respectively, followed by a large increase in their levels. JA and JAME peaked between 12 and 16 h, about 4 h before OPDA and OPDAME. However, OPDA accumulated up to a 2.5-fold higher level than the other compounds. Dihomo-JA and 9, 13-didehydro-OPDA were identified as minor components. Kinetic analyses revealed that a transient threshold of jasmonates or octadecanoids is necessary and sufficient to initiate JA-responsive gene expression. Although OPDA and OPDAME applied exogenously were metabolized to JA in considerable amounts, both of them can induce gene expression, as evidenced by those genes that did not respond to endogenously formed JA. Also, coronatine induces JA-responsive genes independently from endogenous JA. Application of deuterated JA showed that endogenous synthesis of JA is not induced by JA treatment. The data are discussed in terms of distinct signaling pathways.

Published
2000

125. (+)-7-iso-Jasmonoyl-L-isoleucine is the endogenous bioactive jasmonate

Author

Ministerio de Ciencia y Tecnología (España), Comunidad de Madrid, Fundação para a Ciência e a Tecnologia (Portugal), Ministerio de Educación y Ciencia (España), European Commission, Fonseca, Sandra, Chini, Andrea, Hamberg, Mats, Adie, B., Porzel, Andrea, Kramell, Robert, Miersch, Otto, Wasternack, Claus, Solano, Roberto, Ministerio de Ciencia y Tecnología (España), Comunidad de Madrid, Fundação para a Ciência e a Tecnologia (Portugal), Ministerio de Educación y Ciencia (España), European Commission, Fonseca, Sandra, Chini, Andrea, Hamberg, Mats, Adie, B., Porzel, Andrea, Kramell, Robert, Miersch, Otto, Wasternack, Claus, and Solano, Roberto

Abstract

Hormone-triggered activation of the jasmonate signaling pathway in Arabidopsis thaliana requires SCFCOI1-mediated proteasome degradation of JAZ repressors. (−)-JA-L-Ile is the proposed bioactive hormone, and SCFCOI1 is its likely receptor. We found that the biological activity of (−)-JA-L-Ile is unexpectedly low compared to coronatine and the synthetic isomer (+)-JA-L-Ile, which suggests that the stereochemical orientation of the cyclopentanone-ring side chains greatly affects receptor binding. Detailed GC-MS and HPLC analyses showed that the (−)-JA-L-Ile preparations currently used in ligand binding studies contain small amounts of the C7 epimer (+)-7-iso-JA-L-Ile. Purification of each of these molecules demonstrated that pure (−)-JA-L-Ile is inactive and that the active hormone is (+)-7-iso-JA-L-Ile, which is also structurally more similar to coronatine. In addition, we show that pH changes promote conversion of (+)-7-iso-JA-L-Ile to the inactive (−)-JA-L-Ile form, thus providing a simple mechanism that can regulate hormone activity through epimerization.

Published
2009

135. Disruption of Adenosine-5′-Phosphosulfate Kinase inArabidopsisReduces Levels of Sulfated Secondary Metabolites

Author

Mugford, Sarah G., primary, Yoshimoto, Naoko, additional, Reichelt, Michael, additional, Wirtz, Markus, additional, Hill, Lionel, additional, Mugford, Sam T., additional, Nakazato, Yoshimi, additional, Noji, Masaaki, additional, Takahashi, Hideki, additional, Kramell, Robert, additional, Gigolashvili, Tamara, additional, Flügge, Ulf-Ingo, additional, Wasternack, Claus, additional, Gershenzon, Jonathan, additional, Hell, Rüdiger, additional, Saito, Kazuki, additional, and Kopriva, Stanislav, additional

Published
2009
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137. ADP-Glucose Pyrophosphorylase-Deficient Pea Embryos Reveal Specific Transcriptional and Metabolic Changes of Carbon-Nitrogen Metabolism and Stress Responses

Author

Weigelt, Kathleen, primary, Küster, Helge, additional, Rutten, Twan, additional, Fait, Aaron, additional, Fernie, Alisdair R., additional, Miersch, Otto, additional, Wasternack, Claus, additional, Emery, R. J. Neil, additional, Desel, Christine, additional, Hosein, Felicia, additional, Müller, Martin, additional, Saalbach, Isolde, additional, and Weber, Hans, additional

Published
2008
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147. Jasmonic Acid and Its Precursor 12-Oxophytodienoic Acid Control Different Aspects of Constitutive and Induced Herbivore Defenses in Tomato.

Author

Bosch, Marko, Wright, Louwrance P., Gershenzon, Jonathan, Wasternack, Claus, Hause, Bettina, Schaller, Andreas, and Stintzi, Annick

Subjects
JASMONATE, ISOLEUCINE, JASMONIC acid, TOMATO genetics, TERPENES synthesis, MANDUCA
Abstract

The jasmonate family of growth regulators includes the isoleucine (Ile) conjugate of jasmonic acid (JA-Ile) and its biosynthetic precursor 12-oxophytodienoic acid (OPDA) as signaling molecules. To assess the relative contribution of JA/JA-Ile and OPDA to insect resistance in tomato (Solanum lycopersicum), we silenced the expression of OPDA reductase3 (OPR3) by RNA interference (RNAi). Consistent with a block in the biosynthetic pathway downstream of OPDA, OPR3-RNAi plants contained wild-type levels of OPDA but failed to accumulate JA or JA-Ile after wounding. JA/JA-Ile deficiency in OPR3-RNAi plants resulted in reduced trichome formation and impaired monoterpene and sesquiterpene production. The loss of these JA/JA-Ile -dependent defense traits rendered them more attractive to the specialist herbivore Manduca sexta with respect to feeding and oviposition. Oviposition preference resulted from reduced levels of repellant monoterpenes and sesquiterpenes. Feeding preference, on the other hand, was caused by increased production of cis-3-hexenal acting as a feeding stimulant for M. sexta larvae in OPR3-RNAi plants. Despite impaired constitutive defenses and increased palatability of OPR3-RNAi leaves, larval development was indistinguishable on OPR3-RNAi and wild-type plants, and was much delayed compared with development on the jasmonic acid-insensitive1 (jai1) mutant. Apparently, signaling through JAI1, the tomato ortholog of the ubiquitin ligase CORONATINE INSENSITIVE1 in Arabidopsis (Arabidopsis thaliana), is required for defense, whereas the conversion of OPDA to JA/JA-Ile is not. Comparing the signaling activities of OPDA and JA/JA-Ile, we found that OPDA can substitute for JA/JA-Ile in the local induction of defense gene expression, but the production of JA/JA-Ile is required for a systemic response. [ABSTRACT FROM AUTHOR]

Published
2014
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148. Perception, signaling and cross-talk of jasmonates and the seminal contributions of the Daoxin Xie's lab and the Chuanyou Li's lab.

Author

Wasternack, Claus

Subjects
*SENSORY perception, *JASMONATE, *LIPIDS, *ABIOTIC stress, *ISOLEUCINE, *CELLULAR signal transduction, *GENE expression
Abstract

Jasmonates (JAs) are lipid-derived signals in plant responses to biotic and abiotic stresses and in development. The most active JA compound is (+)- 7-iso-JA-Ile, a JA conjugate with isoleucine. Biosynthesis, metabolism and key components of perception and signal transduction have been identified and numerous JA-induced gene expression data collected. For JA-Ile perception, the SCF-JAZ co-receptor complex has been identified and crystalized. Activators such as MYC2 and repressors such as JAZs including their targets were found. Involvement of JA-Ile in response to herbivores and pathogens and in root growth inhibition is among the most studied aspects of JA-Ile signaling. There are an increasing number of examples, where JA-Ile shows cross-talk with other plant hormones. Seminal contributions in JA/JA-Ile research were given by Daoxin Xie's lab and Chuanyou Li's lab, both in Beijing. Here, characterization was done regarding components of the JA-Ile receptor, such as COI1 (JAI1) and SCF, regarding activators (MYCs, MYBs) and repressors (JAV1, bHLH IIId's) of JA-regulated gene expression, as well as regarding components of auxin biosynthesis and action, such as the transcription factor PLETHORA active in the root stem cell niche. This overview reflects the work of both labs in the light of our present knowledge on biosynthesis, perception and signal transduction of JA/JA-Ile and its cross-talk to other hormones. [ABSTRACT FROM AUTHOR]

Published
2014
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