@Article{IPB-2322, author = {Ortel, B. and Atzorn, R. and Hause, B. and Feussner, I. and Miersch, O. and Wasternack, C. and}, title = {{Jasmonate-induced gene expression of barley (Hordeum vulgare) leaves - the link between jasmonate and abscisic acid}}, year = {1999}, pages = {113-122}, journal = {Plant Growth Regul.}, doi = {10.1023/A:1006212017458}, volume = {29}, abstract = {In barley leaves a group of genes is expressed in response to treatment with jasmonates and abscisic acid (ABA) [21]. One of these genes coding for a jasmonate-induced protein of 23 kDa (JIP-23) was analyzed to find out the link between ABA and jasmonates by recording its expression upon modulating independently, the endogenous level of both of them. By use of inhibitors of JA synthesis and ABA degradation, and the ABA-deficient mutant Az34, as well as of cultivar-specific differences, it was shown that endogenous jasmonate increases are necessary and sufficient for expression of this gene. The endogenous rise of ABA did not induce synthesis of JIP-23, whereas exogenous ABA did not act via jasmonates. Different signalling pathways are suggested and discussed.} } @Article{IPB-2317, author = {Miersch, O. and Bohlmann, H. and Wasternack, C. and}, title = {{Jasmonates and related compounds from Fusarium oxysporum}}, year = {1999}, pages = {517-523}, journal = {Phytochemistry}, doi = {10.1016/S0031-9422(98)00596-2}, volume = {50}, abstract = {The culture filtrate of Fusarium oxysporum f sp matthiolae was inspected on the occurrence of jasmonates and related compounds. Among compounds described for the first time of biological origin are 7-iso-cucurbic acid, (1S,2S)- and (1S,2R)-3-oxo-2-pentylcyclopentane-1-butyric acid, (1S,2S)- and (1S,2R)-3-oxo-2-(2Z-pentenyl)cyclopentane-1-hexanoic acid, (1S,2S)- and (1S,2R)-3-oxo-2-pentylcyclopentane-1-hexanoic acid, (1S,2S)-3-oxo-2-(2Z-pentenyl)cyclopentane-1-octanoic acid, (1S,2S)-3-oxo-2-pentylcyclopentane-1-octanoic acid and N-[9,10-dihydro-7-iso-jasmonoyl]-(S)-isoleucine. The following metabolites were identified for the first time for this fungus: (−)-Jasmonic acid, 9,10-dihydrojasmonic acid and N-[(−)-jasmonoyl-(S)]-isoleucine were major constituents of the culture filtrate, whereas as minor metabolites occurred N-[9,10-dihydrojasmonoyl]-(S)-isoleucine, cucurbic acid and 3-oxo-2-(2Z-pentenyl)cyclopentane-1-butyric acid, 3-oxo-2-(2Z-pentenyl)cyclopentane-1-octanoic acid and 3-oxo-2-pentylcyclopentane-1-octanoic acid. All cyclopentanones found carried a cis- or trans-attached side chain. Didehydro-jasmonates, hydroxylated jasmonates or 12-oxophytodienoic acid could not be detected in the culture filtrate.} } @Article{IPB-2313, author = {Kramell, R. and Miersch, O. and Schneider, G. and Wasternack, C. and}, title = {{Liquid chromatography of jasmonic acid amine conjugates}}, year = {1999}, pages = {42-46}, journal = {Chromatographia}, doi = {10.1007/BF02467185}, volume = {49}, abstract = {Racemic jasmonic acid (3R,7R/3S,7S)-(±)-JA) was chemically conjugated with different biogenic amines originating from aliphatic and aromatic α-amino acids by decarboxylation. The resulting isomeric compounds were subjected to reversed-phase high-performance liquid chromatography (HPLC) and to HPLC on the chiral stationary phases Chiralpak AS and Nucleodex β-PM. Under reversed-phase conditions, all the homologous amine derivatives tested could be separated from each other except the JA-conjugates containing 2-phenyl-ethylamine and 3-methylbutylamine. On both chiral supports the (3R,7R)-(−)-JA conjugates eluted earlier than those of the enantiomeric counterpart (3S,7S)-(\+)-JA. On Chiralpak AS all the isomers studied could be separated to baseline with a mobile phase containingn-hexane and 2-propanol. The calculated resolution factors were between 1.80 and 4.17. The pairs of isomers were also chromatographed on the cyclodextrin stationary phase Nucleodex β-PM with methanol-triethylammonium acetate buffer as mobile phase. Under these conditions resolution factors were between 0.74 and 1.29. The individual isomers were chiroptically characterized by measurement of their circular dichroism.} } @Article{IPB-2312, author = {Kramell, R. and Porzel, A. and Miersch, O. and Schneider, G. and Wasternack, C. and}, title = {{Chromatographic resolution of peptide-like conjugates of jasmonic acid and of cucurbic acid isomers}}, year = {1999}, pages = {103-107}, journal = {J. Chromatogr. A}, doi = {10.1016/S0021-9673(99)00335-0}, volume = {847}, abstract = {The chiral separation of peptide-like conjugates of jasmonic acid and of cucurbic acid isomers was investigated by liquid chromatography on Chiralpak AS and Nucleodex β-PM. The retention sequences reflect distinct chromatographic properties with respect to the chirality of the jasmonic acid part or of the cucurbic acid isomers. The chromatographic behaviour of the amide conjugates on a reversed-phase C18 column provides evidence for the resolution of diastereomeric conjugates depending on the chirality of both constituents of the conjugate molecule. The chromatographic procedures are suitable for the analytical and preparative separation of such conjugates.} } @Article{IPB-2310, author = {Kenton, P. and Mur, L. A. J. and Atzorn, R. and Wasternack, C. and Draper, J. and}, title = {{(—)-Jasmonic Acid Accumulation in Tobacco Hypersensitive Response Lesions}}, year = {1999}, pages = {74-78}, journal = {Mol. Plant Microbe Interact.}, doi = {10.1094/MPMI.1999.12.1.74}, volume = {12}, abstract = {Tobacco infected with Pseudomonas syringae pv. phaseolicola undergoes a hypersensitive response (HR). Jasmonic acid (JA) accumulated within the developing lesion 3 to 9 h after infection and this accumulation preceded protein loss, cell death, and malondialdehyde accumulation. Accumulating JA consisted largely of the (—)-JA stereoisomer and was essentially restricted to the HR lesion.} } @Article{IPB-2309, author = {Herde, O. and Peña Cortés, H. and Wasternack, C. and Willmitzer, L. and Fisahn, J. and}, title = {{Electric Signaling and Pin2 Gene Expression on Different Abiotic Stimuli Depend on a Distinct Threshold Level of Endogenous Abscisic Acid in Several Abscisic Acid-Deficient Tomato Mutants}}, year = {1999}, pages = {213-218}, journal = {Plant Physiol.}, doi = {10.1104/pp.119.1.213}, volume = {119}, abstract = {Experiments were performed on three abscisic acid (ABA)-deficient tomato (Lycopersicon esculentum Mill.) mutants, notabilis,flacca, and sitiens, to investigate the role of ABA and jasmonic acid (JA) in the generation of electrical signals and Pin2 (proteinaseinhibitor II) gene expression. We selected these mutants because they contain different levels of endogenous ABA. ABA levels in the mutant sitiens were reduced to 8% of the wild type, in notabilis they were reduced to 47%, and in flacca they were reduced to 21%. In wild-type and notabilis tomato plants the induction ofPin2 gene expression could be elicited by heat treatment, current application, or mechanical wounding. Inflacca and sitiens only heat stimulation induced Pin2 gene expression. JA levels inflacca and sitiens plants also accumulated strongly upon heat stimulation but not upon mechanical wounding or current application. Characteristic electrical signals evolved in the wild type and in the notabilis andflacca mutants consisting of a fast action potential and a slow variation potential. However, in sitiens only heat evoked electrical signals; mechanical wounding and current application did not change the membrane potential. In addition, exogenous application of ABA to wild-type tomato plants induced transient changes in membrane potentials, indicating the involvement of ABA in the generation of electrical signals. Our data strongly suggest the presence of a minimum threshold value of ABA within the plant that is essential for the early events in electrical signaling and mediation of Pin2 gene expression upon wounding. In contrast, heat-induced Pin2 gene expression and membrane potential changes were not dependent on the ABA level but, rather, on the accumulation of JA.} } @Article{IPB-2308, author = {Hause, B. and Hertel, S. C. and Klaus, D. and Wasternack, C. and}, title = {{Cultivar-Specific Expression of the Jasmonate-Induced Protein of 23 kDa (JIP-23) Occurs in Hordeum vulgare L. by Jasmonates but not During Seed Germination}}, year = {1999}, pages = {83-89}, journal = {Plant Biol.}, doi = {10.1111/j.1438-8677.1999.tb00712.x}, volume = {1}, abstract = {Treatment of barley leaf segments with jasmonic acid methyl ester (JM) leads to the accumulation of a set of newly formed abundant proteins. Among them, the most abun dant protein exhibits a molecular mass of 23 kDa (JIP‐23). Here, data are presented on the occurrence and expression of the lIP‐23 genes in different cultivars of Hordeum vulgare . Southern blot analysis of 80 cultivars revealed the occurrence of 2 to 4 genes coding for JIP‐23 in all cultivars. By means of Northern blot and immunoblot analysis it is shown that some cultivars lack the ex pression of jip‐23 upon treatment of primary leaves with JM as well as upon stress performed by incubation with 1 M sorbitol solution. During germination, however, all tested cultivars ex hibited developmental expression of jip‐23 . The results are dis cussed in terms of possible functions of JIP‐23 in barley.} } @Article{IPB-2307, author = {Hause, B. and Vörös, K. and Kogel, K.-H. and Besser, K. and Wasternack, C. and}, title = {{A Jasmonate-responsive Lipoxygenase of Barley Leaves is Induced by Plant Activators but not by Pathogens}}, year = {1999}, pages = {459-462}, journal = {J. Plant Physiol.}, doi = {10.1016/S0176-1617(99)80283-1}, volume = {154}, abstract = {Using the recently isolated eDNA clone LOX2 : Hv : 1 which codes for the most abundant jasmonateinducible lipoxygenase (LOX) in barley leaves (Vörös et al., 1998), we analysed the capability of different activators of systemic activated resistance (SAR) to induce the expression of that LOX. Upon treatment of barley leaves with salicylate, 2,6-dichloroisonicotinic acid and benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester, all these compounds were able to induce the expression of the LOX2 : Hv : 1 gene, whereas upon infection with the powdery mildew fungus (Blumeria graminis f. sp. hordei) mRNA accumulation was not detectable in compatible or in incompatible interactions. The induction of the LOX2 : Hv : 1 protein by SAR activators and the expression of different sets of genes induced by jasmonate and salicylate, respectively, are discussed in relation to defense responses against pathogenic fungi.} } @Article{IPB-2305, author = {Gago-Zachert, S. and Costa, N. and Semorile, L. and Grau, O. and}, title = {{Sequence variability in p27 gene of Citrus Tristeza Virus (CTV) revealed by SSCP analysis}}, year = {1999}, pages = {41-50}, journal = {Electron. J. Biotechnol.}, doi = {10.2225/vol2-issue1-fulltext-3}, volume = {2}, abstract = {Citrus tristeza closterovirus (CTV), is a phloem-limited virus transmitted by aphids in a semipersistent manner. The genome of CTV is composed of a ssRNA with two capsid proteins: CP, covering about 95% of the particle length, and a diverged coat protein (dCP), present only in one end of the particle, forming a rattlesnake structure. dCP is the product of p27 gene for which it is also postulated a function in the transmissibility by aphid vectors. Hybridization analysis showed a p27 gene region, which exhibits different patterns with two probes derived from two biological distinct CTV isolates. In an attempt to screen whether that gene region differs in mild and severe strains, six CTV isolates belonging to different biogroups were compared for variations in their p27 gene by analysis of single-strand conformation polymorphism (SSCP). The p27 gene was reverse transcribed and amplified by PCR and thirty clones of each isolate were obtained. From each clone, two fragments of the gene were amplified by PCR: fragment (a), 459 bp long, and fragment (b), 281 bp long. Sequence variations in both gene fragments were studied by SSCP analysis. A variety of SSCP patterns was obtained from each isolate, being isolates belonging to the groups II-IV and III those with the higher and lower number of them. Moreover, SSCP analysis provided a rapid procedure to screen the genetic heterogeneity of the viral isolates reducing considerably the amount of nucleic acid sequenciation necessary to gain that knowledge.} } @Article{IPB-2320, author = {Morgan, K. E. and Zarembinski, T. I. and Theologis, A. and Abel, S. and}, title = {{Biochemical characterization of recombinant polypeptides corresponding to the predicted βαα fold in Aux/IAA proteins}}, year = {1999}, pages = {283-287}, journal = {FEBS Lett.}, doi = {10.1016/S0014-5793(99)00819-4}, volume = {454}, abstract = {The plant hormone indoleacetic acid (IAA or auxin) transcriptionally activates a select set of early genes. The Auxl IAA class of early auxin-responsive genes encodes a large family of short-lived, nuclear proteins. Aux/IAA polypeptides homo-and heterodimerize, and interact with auxin-response transcription factors (ARFs) via C-terminal regions conserved in both protein families. This shared region contains a predicted βαα motif similar to the prokaryotic β-Ribbon DNA binding domain, which mediates both protein dimerization and DNA recognition. Here, we show by circular dichroism spectroscopy and by chemical cross-linking experiments that recombinant peptides corresponding to the predicted βαα region of three Aux/IAA proteins from Arabidopsis thaliana contain substantial α-helical secondary structure and undergo homo- and heterotypic interactions in vitro. Our results indicate a similar biochemical function of the plant βαα domain and suggest that the βαα fold plays an important role in mediating combinatorial interactions of Aux/IAA and ARF proteins to specifically regulate secondary gene expression in response to auxin.} } @Article{IPB-2319, author = {Miersch, O. and Kramell, R. and Parthier, B. and Wasternack, C. and}, title = {{Structure–activity relations of substituted, deleted or stereospecifically altered jasmonic acid in gene expression of barley leaves}}, year = {1999}, pages = {353-361}, journal = {Phytochemistry}, doi = {10.1016/S0031-9422(98)00597-4}, volume = {50}, abstract = {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.} } @Article{IPB-2318, author = {Miersch, O. and Porzel, A. and Wasternack, C. and}, title = {{Microbial conversion of jasmonates - hydroxylations by Aspergillus niger}}, year = {1999}, pages = {1147-1152}, journal = {Phytochemistry}, doi = {10.1016/S0031-9422(98)00698-0}, volume = {50}, abstract = {Aspergillus niger is able to hydroxylate the pentenyl side chain of (−)-jasmonic acid (JA) leading to (11S)- (−)-hydroxy-JA/ (11R)- (−)-hydroxy-JA (2:1) and (−)-11,12-didehydro-JA. Methyl (−)-jasmonate (JA-Me) is converted upon hydrolysis. During prolonged cultivation or at non-optimized isolation procedures, the 11-hydroxy- (9Z)-pentenyl side chain may isomerize to (10E)-9-hydroxy- and (9E)-11-hydroxy-compounds by allylic rearrangement. The fungus hydroxylates (±)-9,10-dihydro-JA at position C-11 into 11j-hydroxy-9,10-dihydro-JA. As JA-Me, the methyl dihydro-JA is hydroxylated only upon hydrolysis into the free acid.} }