zur Suche springenzur Navigation springenzum Inhalt springen

Publikationen - Molekulare Signalverarbeitung

Sortieren nach: Erscheinungsjahr Typ der Publikation

Zeige Ergebnisse 1 bis 9 von 9.

Preprints

Drost, H.-G.; Gabel, A.; Domazet-Lošo, T.; Quint, M.; Grosse, I.; Capturing Evolutionary Signatures in Transcriptomes with myTAI bioRxiv (2016) DOI: 10.1101/051565

Combining transcriptome data of biological processes or response to stimuli with evolutionary information such as the phylogenetic conservation of genes or their sequence divergence rates enables the investigation of evolutionary constraints on these processes or responses. Such phylotranscriptomic analyses recently unraveled that mid-developmental transcriptomes of fly, fish, and cress were dominated by evolutionarily conserved genes and genes under negative selection and thus recapitulated the developmental hourglass on the transcriptomic level. Here, we present a protocol for performing phylotranscriptomic analyses on any biological process of interest. When applying this protocol, users are capable of detecting different evolutionary constraints acting on different stages of the biological process of interest in any species. For each step of the protocol, modular and easy-to-use open-source software tools are provided, which enable a broad range of scientists to apply phylotranscriptomic analyses to a wide spectrum of biological questions.
Preprints

Drost, H.-G.; Bellstädt, J.; Ó’Maoiléidigh, D. S.; Silva, A. T.; Gabel, A.; Weinholdt, C.; Ryan, P. T.; Dekkers, B. J. W.; Bentsink, L.; Hilhorst, H.; Ligterink, W.; Wellmer, F.; Grosse, I.; Quint, M.; Post-embryonic hourglass patterns mark ontogenetic transitions in plant development bioRxiv (2015) DOI: 10.1101/035527

The historic developmental hourglass concept depicts the convergence of animal embryos to a common form during the phylotypic period. Recently, it has been shown that a transcriptomic hourglass is associated with this morphological pattern, consistent with the idea of underlying selective constraints due to intense molecular interactions during body plan establishment. Although plants do not exhibit a morphological hourglass during embryogenesis, a transcriptomic hourglass has nevertheless been identified in the model plant Arabidopsis thaliana. Here, we investigated whether plant hourglass patterns are also found post-embryonically. We found that the two main phase changes during the life cycle of Arabidopsis, from embryonic to vegetative and from vegetative to reproductive development, are associated with transcriptomic hourglass patterns. In contrast, flower development, a process dominated by organ formation, is not. This suggests that plant hourglass patterns are decoupled from organogenesis and body plan establishment. Instead, they may reflect general transitions through organizational checkpoints.
Publikation

Stenzel, I.; Hause, B.; Miersch, O.; Kurz, T.; Maucher, H.; Weichert, H.; Ziegler, J.; Feussner, I.; Wasternack, C.; Jasmonate biosynthesis and the allene oxide cyclase family of Arabidopsis thaliana Plant Mol. Biol. 51, 895-911, (2003) DOI: 10.1023/A:1023049319723

In biosynthesis of octadecanoids and jasmonate (JA), the naturally occurring enantiomer is established in a step catalysed by the gene cloned recently from tomato as a single-copy gene (Ziegler et al., 2000). Based on sequence homology, four full-length cDNAs were isolated from Arabidopsis thaliana ecotype Columbia coding for proteins with AOC activity. The expression of AOCgenes was transiently and differentially up-regulated upon wounding both locally and systemically and was induced by JA treatment. In contrast, AOC protein appeared at constitutively high basal levels and was slightly increased by the treatments. Immunohistochemical analyses revealed abundant occurrence of AOC protein as well as of the preceding enzymes in octadecanoid biosynthesis, lipoxygenase (LOX) and allene oxide synthase (AOS), in fully developed tissues, but much less so in 7-day old leaf tissues. Metabolic profiling data of free and esterified polyunsaturated fatty acids and lipid peroxidation products including JA and octadecanoids in wild-type leaves and the jasmonate-deficient mutant OPDA reductase 3 (opr3) revealed preferential activity of the AOS branch within the LOX pathway. 13-LOX products occurred predominantly as esterified derivatives, and all 13-hydroperoxy derivatives were below the detection limits. There was a constitutive high level of free 12-oxo-phytodienoic acid (OPDA) in untreated wild-type and opr3 leaves, but an undetectable expression of AOC. Upon wounding opr3 leaves exhibited only low expression of AOC, wounded wild-type leaves, however, accumulated JA and AOC mRNA. These and further data suggest regulation of JA biosynthesis by OPDA compartmentalization and a positive feedback by JA during leaf development.
Publikation

Stenzel, I.; Hause, B.; Maucher, H.; Pitzschke, A.; Miersch, O.; Ziegler, J.; Ryan, C. A.; Wasternack, C.; Allene oxide cyclase dependence of the wound response and vascular bundle-specific generation of jasmonates in tomato - amplification in wound signalling Plant J. 33, 577-589, (2003) DOI: 10.1046/j.1365-313X.2003.01647.x

The allene oxide cyclase (AOC)‐catalyzed step in jasmonate (JA) biosynthesis is important in the wound response of tomato. As shown by treatments with systemin and its inactive analog, and by analysis of 35S::prosysteminsense and 35S::prosysteminantisense plants, the AOC seems to be activated by systemin (and JA) leading to elevated formation of JA. Data are presented on the local wound response following activation of AOC and generation of JA, both in vascular bundles. The tissue‐specific occurrence of AOC protein and generation of JA is kept upon wounding or other stresses, but is compromised in 35S::AOCsense plants, whereas 35S::AOCantisense plants exhibited residual AOC expression, a less than 10% rise in JA, and no detectable expression of wound response genes. The (i) activation of systemin‐dependent AOC and JA biosynthesis occurring only upon substrate generation, (ii) the tissue‐specific occurrence of AOC in vascular bundles, where the prosystemin gene is expressed, and (iii) the tissue‐specific generation of JA suggest an amplification in the wound response of tomato leaves allowing local and rapid defense responses.
Publikation

Monostori, T.; Schulze, J.; Sharma, V. K.; Maucher, H.; Wasternack, C.; Hause, B.; Novel plasmid vectors for homologous transformation of barley (Hordeum vulgare L.) with JIP23 cDNA in sense and antisense orientation Cereal Res. Commun. 31, 17-24, (2003) DOI: 10.1007/BF03543245

The most abundant jasmonate-induced protein (JIP) in barley leaves is a 23 kDa protein (JIP23). Its function, however, is unknown. In order to analyze its function by homologous transformation, new plasmid vectors have been constructed. They carry the cDNA coding for JIP23 in sense or antisense orientation under the control of the Ubi-1-promoter as well as the pat resistance gene under the control of the 35S promoter. Barley mesophyll protoplasts were transiently transformed with the sense constructs. PAT activity and immunological detection of JIP23 could be achieved in transformed protoplasts but not in untransformed protoplasts indicating that the construct was active. Thus, these new vectors are suitable for stable transformation of barley. Carrying a multiple cloning site (MCS), these vectors can be used now in a wide range of transformation of barley.
Publikation

Bachmann, A.; Hause, B.; Maucher, H.; Garbe, E.; Vörös, K.; Weichert, H.; Wasternack, C.; Feussner, I.; Jasmonate-Induced Lipid Peroxidation in Barley Leaves Initiated by Distinct 13-LOX Forms of Chloroplasts Biol. Chem. 383, 1645-1657, (2002) DOI: 10.1515/BC.2002.185

In addition to a previously characterized 13-lipoxygenase of 100 kDa encoded by LOX2:Hv:1 [Vörös et al., Eur. J. Biochem. 251 (1998), 36 44], two fulllength cDNAs (LOX2:Hv:2, LOX2:Hv:3) were isolated from barley leaves (Hordeum vulgare cv. Salome) and characterized. Both of them encode 13-lipoxygenases with putative target sequences for chloroplast import. Immunogold labeling revealed preferential, if not exclusive, localization of lipoxygenase proteins in the stroma. The ultrastructure of the chloroplast was dramatically altered following methyl jasmonate treatment, indicated by a loss of thylakoid membranes, decreased number of stacks and appearance of numerous osmiophilic globuli. The three 13-lipoxygenases are differentially expressed during treatment with jasmonate, salicylate, glucose or sorbitol. Metabolite profiling of free linolenic acid and free linoleic acid, the substrates of lipoxygenases, in water floated or jasmonatetreated leaves revealed preferential accumulation of linolenic acid. Remarkable amounts of free 9- as well as 13-hydroperoxy linolenic acid were found. In addition, metabolites of these hydroperoxides, such as the hydroxy derivatives and the respective aldehydes, appeared following methyl jasmonate treatment. These findings were substantiated by metabolite profiling of isolated chloroplasts, and subfractions including the envelope, the stroma and the thylakoids, indicating a preferential occurrence of lipoxygenasederived products in the stroma and in the envelope. These data revealed jasmonateinduced activation of the hydroperoxide lyase and reductase branch within the lipoxygenase pathway and suggest differential activity of the three 13-lipoxygenases under different stress conditions.
Publikation

Ziegler, J.; Stenzel, I.; Hause, B.; Maucher, H.; Hamberg, M.; Grimm, R.; Ganal, M.; Wasternack, C.; Molecular Cloning of Allene Oxide Cyclase J. Biol. Chem. 275, 19132-19138, (2000) DOI: 10.1074/jbc.M002133200

Allene oxide cyclase (EC 5.3.99.6) catalyzes the stereospecific cyclization of an unstable allene oxide to (9S,13S)-12-oxo-(10,15Z)-phytodienoic acid, the ultimate precursor of jasmonic acid. This dimeric enzyme has previously been purified, and two almost identical N-terminal peptides were found, suggesting allene oxide cyclase to be a homodimeric protein. Furthermore, the native protein was N-terminally processed. Using degenerate primers, a polymerase chain reaction fragment could be generated from tomato, which was further used to isolate a full-length cDNA clone of 1 kilobase pair coding for a protein of 245 amino acids with a molecular mass of 26 kDa. Whereas expression of the whole coding region failed to detect allene oxide cyclase activity, a 5′-truncated protein showed high activity, suggesting that additional amino acids impair the enzymatic function. Steric analysis of the 12-oxophytodienoic acid formed by the recombinant enzyme revealed exclusive (>99%) formation of the 9S,13Senantiomer. Exclusive formation of this enantiomer was also found in wounded tomato leaves. Southern analysis and genetic mapping revealed the existence of a single gene for allene oxide cyclase located on chromosome 2 of tomato. Inspection of the N terminus revealed the presence of a chloroplastic transit peptide, and the location of allene oxide cyclase protein in that compartment could be shown by immunohistochemical methods. Concomitant with the jasmonate levels, the accumulation of allene oxide cyclase mRNA was transiently induced after wounding of tomato leaves.
Publikation

Maucher, H.; Hause, B.; Feussner, I.; Ziegler, J.; Wasternack, C.; Allene oxide synthases of barley (Hordeum vulgare cv. Salome): tissue specific regulation in seedling development Plant J. 21, 199-213, (2000) DOI: 10.1046/j.1365-313x.2000.00669.x

Allene oxide synthase (AOS) is the first enzyme in the lipoxygenase (LOX) pathway which leads to formation of jasmonic acid (JA). Two full‐length cDNAs of AOS designated as AOS1 and AOS2, respectively, were isolated from barley (H. vulgare cv. Salome) leaves, which represent the first AOS clones from a monocotyledonous species. For AOS1, the open reading frame encompasses 1461 bp encoding a polypeptide of 487 amino acids with calculated molecular mass of 53.4 kDa and an isoelectric point of 9.3, whereas the corresponding data of AOS2 are 1443 bp, 480 amino acids, 52.7 kDa and 7.9. Southern blot analysis revealed at least two genes. Despite the lack of a putative chloroplast signal peptide in both sequences, the protein co‐purified with chloroplasts and was localized within chloroplasts by immunocytochemical analysis. The barley AOSs, expressed in bacteria as active enzymes, catalyze the dehydration of LOX‐derived 9‐ as well as 13‐hydroperoxides of polyenoic fatty acids to the unstable allene oxides. In leaves, AOS mRNA accumulated upon treatment with jasmonates, octadecanoids and metabolizable carbohydrates, but not upon floating on abscisic acid, NaCl, Na‐salicylate or infection with powdery mildew. In developing seedlings, AOS mRNA strongly accumulated in the scutellar nodule, but less in the leaf base. Both tissues exhibited elevated JA levels. In situ hybridizations revealed the preferential occurrence of AOS mRNA in parenchymatic cells surrounding the vascular bundles of the scutellar nodule and in the young convoluted leaves as well as within the first internode. The properties of both barley AOSs, their up‐regulation of their mRNAs and their tissue specific expression suggest a role during seedling development and jasmonate biosynthesis.
Publikation

Hause, B.; Stenzel, I.; Miersch, O.; Maucher, H.; Kramell, R.; Ziegler, J.; Wasternack, C.; Tissue-specific oxylipin signature of tomato flowers: allene oxide cyclase is highly expressed in distinct flower organs and vascular bundles Plant J. 24, 113-126, (2000) DOI: 10.1046/j.1365-313x.2000.00861.x

A crucial step in the biosynthesis of jasmonic acid (JA) is the formation of its correct stereoisomeric precursor, cis (+)12‐oxophytodienoic acid (OPDA). This step is catalysed by allene oxide cyclase (AOC), which has been recently cloned from tomato . In stems, young leaves and young flowers, AOC mRNA accumulates to a low level , contrasting with a high accumulation in flower buds, flower stalks and roots. The high levels of AOC mRNA and AOC protein in distinct flower organs correlate with high AOC activity, and with elevated levels of JA, OPDA and JA isoleucine conjugate. These compounds accumulate in flowers to levels of about 20 nmol g−1 fresh weight, which is two orders of magnitude higher than in leaves. In pistils, the level of OPDA is much higher than that of JA, whereas in flower stalks, the level of JA exceeds that of OPDA. In other flower tissues, the ratios among JA, OPDA and JA isoleucine conjugate differ remarkably, suggesting a tissue‐specific oxylipin signature. Immunocytochemical analysis revealed the specific occurrence of the AOC protein in ovules, the transmission tissue of the style and in vascular bundles of receptacles, flower stalks, stems, petioles and roots. Based on the tissue‐specific AOC expression and formation of JA, OPDA and JA amino acid conjugates, a possible role for these compounds in flower development is discussed in terms of their effect on sink–source relationships and plant defence reactions. Furthermore, the AOC expression in vascular bundles might play a role in the systemin‐mediated wound response of tomato.
  • Die Leibniz-Gemeinschaft
  • Digitalisierung in der Landwirtschaft
  • Martin-Luther Universität Halle
IPB Mainnav Search