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Publikation

Kramell, R.; Miersch, O.; Atzorn, R.; Parthier, B.; Wasternack, C.; Octadecanoid-Derived Alteration of Gene Expression and the “Oxylipin Signature” in Stressed Barley Leaves. Implications for Different Signaling Pathways Plant Physiol. 123, 177-188, (2000) DOI: 10.1104/pp.123.1.177

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.
Publikation

Miersch, O.; Kramell, R.; Parthier, B.; Wasternack, C.; Structure–activity relations of substituted, deleted or stereospecifically altered jasmonic acid in gene expression of barley leaves Phytochemistry 50, 353-361, (1999) DOI: 10.1016/S0031-9422(98)00597-4

Jasmonic acid and 66 structurally related compounds were tested to find the structural requirements which induce the expression of jasmonate-responsive genes in barley. An intact cyclopentanone ring as well as a pentenyl side chain exhibiting only minor alterations are necessary for this activity. The (−)-enantiomeric and the (+)-7-iso-enantiomeric structure increase activity of jasmonoyl compounds.
Publikation

Wasternack, C.; Miersch, O.; Kramell, R.; Hause, B.; Ward, J.; Beale, M.; Boland, W.; Parthier, B.; Feussner, I.; Jasmonic acid: biosynthesis, signal transduction, gene expression Fett/Lipid 100, 139-146, (1998) DOI: 10.1002/(SICI)1521-4133(19985)100:4/5<139::AID-LIPI139>3.0.CO;2-5

Jasmonic acid (JA) is an ubiquitously occurring plant growth regulator which functions as a signal of developmentally or environmentally regulated expression of various genes thereby contributing to the defense status of plants [1–5]. The formation of jasmonates in a lipid‐based signalling pathway via octadecanoids seems to be a common principle for many plant species to express wound‐ and stressinduced genes [4, 5].There are various octadecanoid‐derived signals [3]. Among them, jasmonic acid and its amino acid conjugates are most active in barley, supporting arguments that β‐oxidation is an essential step in lipid‐based JA mediated responses. Furthermore, among derivatives of 12‐oxophytodienoic acid (PDA) carrying varying length of the carboxylic acid side‐chain, only those with a straight number of carbon atoms are able to induce JA responsive genes in barley leaves after treatment with these compounds. Barley leaves stressed by treatment with sorbitol solutions exhibit mainly an endogenous rise of JA and JA amino acid conjugates suggesting that both of them are stress signals. Data on organ‐ and tissue‐specific JA‐responsive gene expression will be presented and discussed in terms of “JA as a master switch” among various lipid‐derived signals.
Publikation

Wasternack, C.; Ortel, B.; Miersch, O.; Kramell, R.; Beale, M.; Greulich, F.; Feussner, I.; Hause, B.; Krumm, T.; Boland, W.; Parthier, B.; Diversity in octadecanoid-induced gene expression of tomato J. Plant Physiol. 152, 345-352, (1998) DOI: 10.1016/S0176-1617(98)80149-1

In tomato plants wounding leads to up-regulation of various plant defense genes via jasmonates (Ryan, 1992; Bergey et al., 1996). Using this model system of jasmonic acid (JA) signalling, we analyzed activity of octadecanoids to express JA-responsive genes. Leaf treatments were performed with naturally occurring octadecanoids and their molecular mimics such as coronatine or indanone conjugates. JA responses were recorded in terms of up- or down-regulation of various genes by analyzing transcript accumulation, and at least partially in vitro translation products and polypeptide pattern of leaf extracts. The data suggest: (i) 12-Oxo-phytodienoic acid and other intermediates of the octadecanoid pathway has to be ß-oxidized to give a JA response, (ii) Octadecanoids which can not be ß-oxidized are inactive, (iii) JA, its methyl ester (JM), and its amino acid conjugates are most active signals in tomato leaves leading to up regulation of mainly wound-inducible genes and down-regulation of mainly <house-keeping> genes, (iv) Some compounds carrying a JA/JM- or JA amino acid conjugate-like structure induce/repress only a subset of genes suggesting diversity of JA signalling.
Publikation

Vörös, K.; Feussner, I.; Kühn, H.; Lee, J.; Graner, A.; Löbler, M.; Parthier, B.; Wasternack, C.; Characterization of a methyljasmonate-inducible lipoxygenase from barley (Hordeum vulgare cv. Salome) leaves Eur. J. Biochem. 251, 36-44, (1998) DOI: 10.1046/j.1432-1327.1998.2510036.x

We found three methyl jasmonate−induced lipoxygenases with molecular masses of 92 kDa, 98 kDa, and 100 kDa (LOX‐92, ‐98 and ‐100) [Feussner, I., Hause, B., Vörös, K., Parthier, B. & Wasternack, C. (1995) Plant J. 7 , 949−957]. At least two of them (LOX‐92 and LOX‐100), were shown to be localized within chloroplasts of barley leaves. Here, we describe the isolation of a cDNA (3073 bp) coding for LOX‐100, a protein of 936 amino acid residues and a molecular mass of 106 kDa. By sequence comparison this lipoxygenase could be identified as LOX2‐type lipoxygenase and was therefore designated LOX2 : Hv : 1 . The recombinant lipoxygenase was expressed in Escherichia coli and characterized as linoleate 13‐LOX and arachidonate 15‐LOX, respectively. The enzyme exhibited a pH optimum around pH 7.0 and a moderate substrate preference for linoleic acid. The gene was transiently expressed after exogenous application of jasmonic acid methyl ester with a maximum between 12 h and 18 h. Its expression was not affected by exogenous application of abscisic acid. Also a rise of endogenous jasmonic acid resulting from sorbitol stress did not induce LOX2 : Hv : 1 , suggesting a separate signalling pathway compared with other jasmonate‐induced proteins of barley. The properties of LOX2 : Hv : 1 are discussed in relation to its possible involvement in jasmonic acid biosynthesis and other LOX forms of barley identified so far.
Publikation

Ratajczak, R.; Feussner, I.; Hause, B.; Böhm, A.; Parthier, B.; Wasternack, C.; Alteration of V-type H+-ATPase during methyljasmonate-induced senescence in barley (Hordeum vulgare L. cv. Salome) J. Plant Physiol. 152, 199-206, (1998) DOI: 10.1016/S0176-1617(98)80133-8

In barley leaves, the application of (−)-jasmonic acid or its methyl ester (JAME) induces a senescencelike phenotype. This is accompanied by the synthesis of abundant proteins, so-called jasmonate-induced proteins (JlPs). Here, we show that modifications of vacuolar H+-ATPase (V-ATPase) subunits are jasmo-nate inducible. Using immunofluorescence analysis, we demonstrate that V-ATPase of barley leaves is exclusively located at the tonoplast also upon JAME treatment. Total ATP-hydrolysis activity of microsomal fractions increased by a factor of 10 during 72 h of JAME-treatment, while Bafilomycin Ai-sensitive ATP-hydrolysis activity, which is usually referred to V-ATPase activity, increased by a factor of about 2 in tono-plast-enriched membrane fractions. Moreover, due to JAME treatment there was a pronounced increase in ATP-hydrolysis activity at pH 6.2. This activity was not affected by inhibitors of P-, F-, or V-ATPases. However, biochemical analysis of partially purified V-ATPase suggests, that this activity might be due at least in part to the V-ATPase. JAME-treatment seems to change biochemical properties of the V-ATPase, i.e. a shift of the pH optimum of activity to a more acidic pH and a decrease in Bafilomycin A1 sensitivity. This is accompanied by the appearance of several additional forms of V-ATPase subunits which might represent either different isoforms or post-translationally modified proteins. We suggest that these changes in properties of the V-ATPase, which is involved in house-keeping and stress responses, may be due to JAME-induced senescence to overcome concomitant changes of the vacuolar membrane.
Publikation

Miersch, O.; Knöfel, H.-D.; Schmidt, J.; Kramell, R.; Parthier, B.; A jasmonic acid conjugate, N-[(—)-jasmonoyl]-tyramine, from Petunia pollen Phytochemistry 47, 327-329, (1998) DOI: 10.1016/S0031-9422(97)00617-1

A new jasmonate, N-[(—)-jasmonoyl]-tyramine, was identified from petunia pollen in which (—)-jasmonic acid was detected and quantified.
Publikation

Wasternack, C.; Parthier, B.; Jasmonate-signalled plant gene expression Trends Plant Sci. 2, 302-307, (1997) DOI: 10.1016/S1360-1385(97)89952-9

Jasmonic acid is distributed throughout higher plants, synthesized from linolenic acid via the octadecanoic pathway. An important and probably essential role seems to be its operation as a ‘master switch’, responsible for the activation of signal transduction pathways in response to predation and pathogen attack. Proteins encoded by jasmonate-induced genes include enzymes of alkaloid and phytoalexin synthesis, storage proteins, cell wall constituents and stress protectants. The wound-induced formation of proteinase inhibitors is a well-studied example, in which jasmonic acid combines with abscisic acid and ethylene to protect the plant from predation.
Publikation

Lee, J.; Vogt, T.; Schmidt, J.; Parthier, B.; Löbler, M.; Methyljasmonate-induced accumulation of coumaroyl conjugates in barley leaf segments Phytochemistry 44, 589-592, (1997) DOI: 10.1016/S0031-9422(96)00562-6

The effect of methyljasmonate on the induction of phenolic components in barley leaf segments was investigated. RP-HPLC of methanol extracts showed that three compounds accumulate to high concentrations in response to methyljasmonate treatment. Two of them were identified as N-(E)-4-coumaroylputrescine and N-(E)-4-coumaroylagmatine by UV-spectroscopy and mass spectrometry.
Publikation

Kramell, R.; Miersch, O.; Hause, B.; Ortel, B.; Parthier, B.; Wasternack, C.; Amino acid conjugates of jasmonic acid induce jasmonate-responsive gene expression in barley (Hordeum vulgare L.) leaves FEBS Lett. 414, 197-202, (1997) DOI: 10.1016/S0014-5793(97)01005-3

Leaves of barley (Hordeum vulgare L. cv. Salome ) treated with jasmonic acid (JA), its methyl ester (JM), or its amino acid conjugates exhibit up‐regulation of specific genes and down‐regulation of house‐keeping genes. This transcriptional regulation exhibits several specificities. (i) The (−)‐enantiomers are more active, and conjugates are mainly active if they carry an l ‐amino acid moiety. (ii) The various JA‐responsive genes respond differentially to enantiomeric and chiralic forms. (iii) Both JA and its amino acid conjugates exhibiting no or negligible interconversion induce/repress genes.
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