Hans-Jorg Weber

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Wounding in multicellular eukaryotes results in marked changes in gene expression that contribute to tissue defense and repair. Using a cDNA microarray technique, we analyzed the timing, dynamics, and regulation of the expression of 150 genes in mechanically wounded leaves of Arabidopsis. Temporal accumulation of a group of transcripts was correlated with(More)
The Arabidopsis opr3 mutant is defective in the isoform of 12-oxo-phytodienoate (OPDA) reductase required for jasmonic acid (JA) biosynthesis. Oxylipin signatures of wounded opr3 leaves revealed the absence of detectable 3R,7S-JA as well as altered levels of its cyclopentenone precursors OPDA and dinor OPDA. In contrast to JA-insensitive coi1 plants and to(More)
Jasmonic acid and its precursors are potent regulatory molecules in plants. We devised a method for the simultaneous extraction of these compounds from plant leaves to quantitate changes in the levels of jasmonate family members during health and on wounding. During our study, we identified a novel 16-carbon cyclopentenoic acid in leaf extracts from(More)
We conducted a study of the patterns and dynamics of oxidized fatty acid derivatives (oxylipins) in potato leaves infected with the late-blight pathogen Phytophthora infestans. Two 18-carbon divinyl ether fatty acids, colneleic acid and colnelenic acid, accumulated during disease development. To date, there are no reports that such compounds have been(More)
Physical damage and disease are known to lead to changes in the oxylipin signature of plants. We searched for oxylipins produced in response to both wounding and pathogenesis in Arabidopsis leaves. Linoleic acid 9- and 13-ketodienes (KODEs) were found to accumulate in wounded leaves as well as in leaves infected with the pathogen Pseudomonas syringae pv.(More)
Our earlier work on the recognition of Q beta plus strand RNA by replicase had shown by RNase degradation and by electron microscopic techniques that specific binding interactions occurred at two internal sites, the S-site and the M-site, but not at the 3'-end, i.e. the site of initiation of synthesis. Using essentially similar methods, we have found now(More)
Based on the previously determined amino-acid sequence of lactate dehydrogenase from B. stearothermophilus, an oligonucleotide probe was synthesized and used to clone the structural genes for lactate dehydrogenase from B. stearothermophilus, B. caldolyticus and B. caldotenax. The nucleotide sequences of the entire LDH genes from these three thermophilic(More)
The RNA phage Qbeta requires for the replication of its genome an RNA binding protein called Qbeta host factor or Hfq protein. Our previous results suggested that this protein mediates the access of replicase to the 3'-end of the Qbeta plus strand RNA. Here we report the results of an evolutionary experiment in which phage Qbeta was adapted to an(More)
RNA-protein interactions between bacteriophage Qbeta plus strand RNA and the components of the Qbeta replicase system were studied by deletion analysis. Internal, 5'-terminal and 3'-terminal deletions were assayed for template activity with replicase in vitro. Of the two internal binding sites previously described for replicase, we found that the S-site(More)
The methodology developed for the synthesis of bihelical DNA consists of the following three steps. (1) Chemical synthesis of deoxyribopolynucleotide segments containing 8 to 12 nucleotide units. These should represent the entire two strands of the intended DNA and those belonging to the complementary strands should have an overlap of 4 to 5 nucleotides.(More)