The Experts below are selected from a list of 1041 Experts worldwide ranked by ideXlab platform
Bettina Hause - One of the best experts on this subject based on the ideXlab platform.
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Molecular Cloning of Allene Oxide Cyclase
2020Co-Authors: Irene Stenzel, Bettina Hause, Helmut Maucher, Mats Hamberg, Rudi Grimm, Martin Ganali, Claus Dr. WasternackAbstract:)-phytodienoic acid, the ultimateprecursor of jasmonic acid. This dimeric enzyme haspreviously been purified, and two almost identical N-terminal peptides were found, suggesting allene oxideCyclase to be a homodimeric protein. Furthermore, thenative protein was N-terminally processed. Using de-generate primers, a polymerase chain reaction fragmentcould be generated from tomato, which was further usedto isolate a full-length cDNA clone of 1 kilobase paircoding for a protein of 245 amino acids with a molecularmass of 26 kDa. Whereas expression of the whole codingregion failed to detect allene oxide Cyclase activity, a5
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Jasmonate is required for the response to osmotic stress in rice
Environmental and Experimental Botany, 2020Co-Authors: Gangliang Tang, Bettina Hause, Peter Nick, Junning Ma, Michael RiemannAbstract:Abstract Plants have the ability to alleviate the harmful effects caused by abiotic and biotic stress. Phytohormones play a very important role in the acclimation to these stresses. To study the role of jasmonate in the acclimation to osmotic stress, an ALLENE OXIDE Cyclase (AOC) mutant of rice (cpm2), disrupted in the biosynthesis of jasmonic acid (JA), and its wild type (WT) background were employed to investigate their responses to osmotic stress caused by treatment with polyethylene glycol (PEG) 6000. WT showed tolerance to osmotic stress, correlated with a fast transient increase of JA and JA-isoleucine (JA-Ile) in the shoots prior to an increase in abscisic acid (ABA), followed by a second increase in jasmonates when exposing to osmotic stress during 24 hours. In roots, the pattern of hormonal increase was similar, but the response appeared to be faster, and remained transient, also with respect to low levels of jasmonates upon continuing osmotic stress. The mutant, which was containing extremely low levels of jasmonates, was hypersensitive to the stress. However, ABA accumulated in both, shoots and roots of cpm2, to similar (but not equal) levels as those seen in the WT, demonstrating that the biosynthesis or catabolism of ABA in response to osmotic stress is at least partially independent of JA, but can be modulated by JA. Our results suggest that jasmonates operate in parallel, presumably synergistically, to ABA, and are indispensable for osmotic stress tolerance in rice.
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Activity Regulation by Heteromerization of Arabidopsis Allene Oxide Cyclase Family Members
Plants (Basel Switzerland), 2016Co-Authors: Markus Otto, Claus Wasternack, Christin Naumann, Wolfgang Brandt, Bettina HauseAbstract:Jasmonates (JAs) are lipid-derived signals in plant stress responses and development. A crucial step in JA biosynthesis is catalyzed by allene oxide Cyclase (AOC). Four genes encoding functional AOCs (AOC1, AOC2, AOC3 and AOC4) have been characterized for Arabidopsis thaliana in terms of organ- and tissue-specific expression, mutant phenotypes, promoter activities and initial in vivo protein interaction studies suggesting functional redundancy and diversification, including first hints at enzyme activity control by protein-protein interaction. Here, these analyses were extended by detailed analysis of recombinant proteins produced in Escherichia coli. Treatment of purified AOC2 with SDS at different temperatures, chemical cross-linking experiments and protein structure analysis by molecular modelling approaches were performed. Several salt bridges between monomers and a hydrophobic core within the AOC2 trimer were identified and functionally proven by site-directed mutagenesis. The data obtained showed that AOC2 acts as a trimer. Finally, AOC activity was determined in heteromers formed by pairwise combinations of the four AOC isoforms. The highest activities were found for heteromers containing AOC4 + AOC1 and AOC4 + AOC2, respectively. All data are in line with an enzyme activity control of all four AOCs by heteromerization, thereby supporting a putative fine-tuning in JA formation by various regulatory principles.
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Jasmonates act positively in adventitious root formation in petunia cuttings
BMC Plant Biology, 2015Co-Authors: Sandra Lischweski, Anne Muchow, Daniela Guthörl, Bettina HauseAbstract:Petunia is a model to study the process of adventitious root (AR) formation on leafy cuttings. Excision of cuttings leads to a transient increase in jasmonates, which is regarded as an early, transient and critical event for rooting. Here, the role of jasmonates in AR formation on petunia cuttings has been studied by a reverse genetic approach. To reduce the endogenous levels of jasmonates, transgenic plants were generated expressing a Petunia hybrida ALLENE OXIDE Cyclase (PhAOC)-RNAi construct. The transgenic plants exhibited strongly reduced PhAOC transcript and protein levels as well as diminished accumulation of cis-12-oxo-phytodienoic acid, jasmonic acid and jasmonoyl-isoleucine after wounding in comparison to wild type and empty vector expressing plants. Reduced levels of endogenous jasmonates resulted in formation of lower numbers of ARs. However, this effect was not accompanied by altered levels of auxin and aminocyclopropane carboxylate (ACC, precursor of ethylene) or by impaired auxin and ethylene-induced gene expression. Neither activity of cell-wall invertases nor accumulation of soluble sugars was altered by jasmonate deficiency. Diminished numbers of AR in JA-deficient cuttings suggest that jasmonates act as positive regulators of AR formation in petunia wild type. However, wound-induced rise in jasmonate levels in petunia wild type cuttings seems not to be causal for increased auxin and ethylene levels and for sink establishment.
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Increased tolerance to salt stress in OPDA-deficient rice ALLENE OXIDE Cyclase mutants is linked to an increased ROS-scavenging activity
Journal of Experimental Botany, 2015Co-Authors: Mohamed Hazman, Bettina Hause, Peter Nick, Elisabeth Eiche, Michael RiemannAbstract:Salinity stress represents a global constraint for rice, the most important staple food worldwide. Therefore the role of the central stress signal jasmonate for the salt response was analysed in rice comparing the responses to salt stress for two jasmonic acid (JA) biosynthesis rice mutants (cpm2 and hebiba) impaired in the function of ALLENE OXIDE Cyclase (AOC) and their wild type. The aoc mutants were less sensitive to salt stress. Interestingly, both mutants accumulated smaller amounts of Na + ions in their leaves, and showed better scavenging of reactive oxygen species (ROS) under salt stress. Leaves of the wild type and JA mutants accumulated similar levels of abscisic acid (ABA) under stress conditions, and the levels of JA and its amino acid conjugate, JA–isoleucine (JA-Ile), showed only subtle alterations in the wild type. In contrast, the wild type responded to salt stress by strong induction of the JA precursor 12-oxophytodienoic acid (OPDA), which was not observed in the mutants. Transcript levels of representative salinityinduced genes were induced less in the JA mutants. The absence of 12-OPDA in the mutants correlated not only with a generally increased ROS-scavenging activity, but also with the higher activity of specific enzymes in the antioxidative pathway, such as glutathione S-transferase, and fewer symptoms of damage as, for example, indicated by lower levels of malondialdehyde. The data are interpreted in a model where the absence of OPDA enhanced the antioxidative power in mutant leaves.
Claus Wasternack - One of the best experts on this subject based on the ideXlab platform.
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Shift in Fatty Acid and Oxylipin Pattern of Tomato Leaves Following Overexpression of the Allene Oxide Cyclase
Advanced Research on Plant Lipids, 2020Co-Authors: Heiko Weichert, Helmut Maucher, Claus Wasternack, Ellen Hornung, Ivo FeussnerAbstract:Polyunsaturated fatty acids (PUFAs) are a source of numerous oxidation products, the oxylipins. In leaves, α-linolenic acid (α-LeA) is the preferential substrate for lipid peroxidation reactions. This reaction may be catalyzed either by a 9-lipoxygenase (9-LOX) or by a 13-LOX and oxygen is inserted regioselectively as well as stereospecifically leading to formation of 13 S- or 9 S-hydroperoxy octadecatrienoic acid (13-/9-HPOT; Brash, 1999). At least, seven different enzyme families or reaction branches within the LOX pathway can use these HPOTs or other hydroperoxy PUFAs leading to (i) keto-PUFAs (LOX); (ii) epoxy hydroxy-PUFAs (epoxy alcohol synthase, EAS); (iii) octadecanoids and jasmonates (allene oxide synthase, AOS); (iv) leaf aldehydes and leaf alcohols (hydroperoxide lyase, HPL); (v) hydroxy PUFAs (reductase); (vi) divinyl ether PUFAs (divinyl ether synthase, DES); and (vii) epoxy- or dihydrodiol-PUFAs (peroxygenase, PDX; Fig. 1; Feussner and Wasternack, 2002).
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Activity Regulation by Heteromerization of Arabidopsis Allene Oxide Cyclase Family Members
Plants (Basel Switzerland), 2016Co-Authors: Markus Otto, Claus Wasternack, Christin Naumann, Wolfgang Brandt, Bettina HauseAbstract:Jasmonates (JAs) are lipid-derived signals in plant stress responses and development. A crucial step in JA biosynthesis is catalyzed by allene oxide Cyclase (AOC). Four genes encoding functional AOCs (AOC1, AOC2, AOC3 and AOC4) have been characterized for Arabidopsis thaliana in terms of organ- and tissue-specific expression, mutant phenotypes, promoter activities and initial in vivo protein interaction studies suggesting functional redundancy and diversification, including first hints at enzyme activity control by protein-protein interaction. Here, these analyses were extended by detailed analysis of recombinant proteins produced in Escherichia coli. Treatment of purified AOC2 with SDS at different temperatures, chemical cross-linking experiments and protein structure analysis by molecular modelling approaches were performed. Several salt bridges between monomers and a hydrophobic core within the AOC2 trimer were identified and functionally proven by site-directed mutagenesis. The data obtained showed that AOC2 acts as a trimer. Finally, AOC activity was determined in heteromers formed by pairwise combinations of the four AOC isoforms. The highest activities were found for heteromers containing AOC4 + AOC1 and AOC4 + AOC2, respectively. All data are in line with an enzyme activity control of all four AOCs by heteromerization, thereby supporting a putative fine-tuning in JA formation by various regulatory principles.
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ALLENE OXIDE Cyclase (AOC) gene family members of Arabidopsis thaliana: tissue- and organ-specific promoter activities and in vivo heteromerization*
Journal of Experimental Botany, 2012Co-Authors: Irene Stenzel, Bettina Hause, Otto Miersch, Markus Otto, Carolin Delker, Nils Kirmse, Diana Schmidt, Claus WasternackAbstract:Jasmonates are important signals in plant stress responses and plant development. An essential step in the biosynthesis of jasmonic acid (JA) is catalysed by ALLENE OXIDE Cyclase (AOC) which establishes the naturally occurring enantiomeric structure of jasmonates. In Arabidopsis thaliana, four genes encode four functional AOC polypeptides (AOC1, AOC2, AOC3, and AOC4) raising the question of functional redundancy or diversification. Analysis of transcript accumulation revealed an organ-specific expression pattern, whereas detailed inspection of transgenic lines expressing the GUS reporter gene under the control of individual AOC promoters showed partially redundant promoter activities during development: (i) In fully developed leaves, promoter activities of AOC1, AOC2, and AOC3 appeared throughout all leaf tissue, but AOC4 promoter activity was vascular bundle-specific; (ii) only AOC3 and AOC4 showed promoter activities in roots; and (iii) partially specific promoter activities were found for AOC1 and AOC4 in flower development. In situ hybridization of flower stalks confirmed the GUS activity data. Characterization of single and double AOC loss-of-function mutants further corroborates the hypothesis of functional redundancies among individual AOCs due to a lack of phenotypes indicative of JA deficiency (e.g. male sterility). To elucidate whether redundant AOC expression might contribute to regulation on AOC activity level, protein interaction studies using bimolecular fluorescence complementation (BiFC) were performed and showed that all AOCs can interact among each other. The data suggest a putative regulatory mechanism of temporal and spatial fine-tuning in JA formation by differential expression and via possible heteromerization of the four AOCs.
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The moss Physcomitrella patens contains cyclopentenones but no jasmonates: mutations in allene oxide Cyclase lead to reduced fertility and altered sporophyte morphology.
New Phytologist, 2010Co-Authors: Michael Stumpe, Bettina Hause, Claus Wasternack, Robert Kramell, Cornelia Göbel, Bernd Faltin, Anna K. Beike, Kiyoshi Himmelsbach, Julia Bode, Wolfgang FrankAbstract:Summary • Two cDNAs encoding allene oxide Cyclases (PpAOC1, PpAOC2), key enzymes in the formation of jasmonic acid (JA) and its precursor (9S,13S)-12-oxo-phytodienoic acid (cis-(+)-OPDA), were isolated from the moss Physcomitrella patens. • Recombinant PpAOC1 and PpAOC2 show substrate specificity against the allene oxide derived from 13-hydroperoxy linolenic acid (13-HPOTE); PpAOC2 also shows substrate specificity against the allene oxide derived from 12-hydroperoxy arachidonic acid (12-HPETE). • In protonema and gametophores the occurrence of cis-(+)-OPDA, but neither JA nor the isoleucine conjugate of JA nor that of cis-(+)-OPDA was detected. • Targeted knockout mutants for PpAOC1 and for PpAOC2 were generated, while double mutants could not be obtained. The DPpAOC1 and DPpAOC2 mutants showed reduced fertility, aberrant sporophyte morphology and interrupted sporogenesis.
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Spodoptera littoralis-induced lectin expression in tobacco.
Plant and Cell Physiology, 2009Co-Authors: Gianni Vandenborre, Bettina Hause, Claus Wasternack, Otto Miersch, Guy Smagghe, Els J. M. Van DammeAbstract:The induced defense response in plants towards herbivores is mainly regulated by jasmonates and leads to the accumulation of so-called jasmonate-induced proteins. Recently, a jasmonate (JA) inducible lectin called Nicotiana tabacum agglutinin or NICTABA was discovered in tobacco (N. tabacum cv Samsun) leaves. Tobacco plants also accumulate the lectin after insect attack by caterpillars. To study the functional role of NICTABA, the accumulation of the JA precursor 12-oxophytodienoic acid (OPDA), JA as well as different JA metabolites were analyzed in tobacco leaves after herbivory by larvae of the cotton leafworm (Spodoptera littoralis) and correlated with NICTABA accumulation. It was shown that OPDA, JA as well as its methyl ester can trigger NICTABA accumulation. However, hydroxylation of JA and its subsequent sulfation and glucosylation results in inactive compounds that have lost the capacity to induce NICTABA gene expression. The expression profile of NICTABA after caterpillar feeding was recorded in local as well as in systemic leaves, and compared to the expression of several genes encoding defense proteins, and genes encoding a tobacco systemin and the allene oxide Cyclase, an enzyme in JA biosynthesis. Furthermore, the accumulation of NICTABA was quantified after S. littoralis herbivory and immunofluorescence microscopy was used to study the localization of NICTABA in the tobacco leaf.
Otto Miersch - One of the best experts on this subject based on the ideXlab platform.
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ALLENE OXIDE Cyclase (AOC) gene family members of Arabidopsis thaliana: tissue- and organ-specific promoter activities and in vivo heteromerization*
Journal of Experimental Botany, 2012Co-Authors: Irene Stenzel, Bettina Hause, Otto Miersch, Markus Otto, Carolin Delker, Nils Kirmse, Diana Schmidt, Claus WasternackAbstract:Jasmonates are important signals in plant stress responses and plant development. An essential step in the biosynthesis of jasmonic acid (JA) is catalysed by ALLENE OXIDE Cyclase (AOC) which establishes the naturally occurring enantiomeric structure of jasmonates. In Arabidopsis thaliana, four genes encode four functional AOC polypeptides (AOC1, AOC2, AOC3, and AOC4) raising the question of functional redundancy or diversification. Analysis of transcript accumulation revealed an organ-specific expression pattern, whereas detailed inspection of transgenic lines expressing the GUS reporter gene under the control of individual AOC promoters showed partially redundant promoter activities during development: (i) In fully developed leaves, promoter activities of AOC1, AOC2, and AOC3 appeared throughout all leaf tissue, but AOC4 promoter activity was vascular bundle-specific; (ii) only AOC3 and AOC4 showed promoter activities in roots; and (iii) partially specific promoter activities were found for AOC1 and AOC4 in flower development. In situ hybridization of flower stalks confirmed the GUS activity data. Characterization of single and double AOC loss-of-function mutants further corroborates the hypothesis of functional redundancies among individual AOCs due to a lack of phenotypes indicative of JA deficiency (e.g. male sterility). To elucidate whether redundant AOC expression might contribute to regulation on AOC activity level, protein interaction studies using bimolecular fluorescence complementation (BiFC) were performed and showed that all AOCs can interact among each other. The data suggest a putative regulatory mechanism of temporal and spatial fine-tuning in JA formation by differential expression and via possible heteromerization of the four AOCs.
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Spodoptera littoralis-induced lectin expression in tobacco.
Plant and Cell Physiology, 2009Co-Authors: Gianni Vandenborre, Bettina Hause, Claus Wasternack, Otto Miersch, Guy Smagghe, Els J. M. Van DammeAbstract:The induced defense response in plants towards herbivores is mainly regulated by jasmonates and leads to the accumulation of so-called jasmonate-induced proteins. Recently, a jasmonate (JA) inducible lectin called Nicotiana tabacum agglutinin or NICTABA was discovered in tobacco (N. tabacum cv Samsun) leaves. Tobacco plants also accumulate the lectin after insect attack by caterpillars. To study the functional role of NICTABA, the accumulation of the JA precursor 12-oxophytodienoic acid (OPDA), JA as well as different JA metabolites were analyzed in tobacco leaves after herbivory by larvae of the cotton leafworm (Spodoptera littoralis) and correlated with NICTABA accumulation. It was shown that OPDA, JA as well as its methyl ester can trigger NICTABA accumulation. However, hydroxylation of JA and its subsequent sulfation and glucosylation results in inactive compounds that have lost the capacity to induce NICTABA gene expression. The expression profile of NICTABA after caterpillar feeding was recorded in local as well as in systemic leaves, and compared to the expression of several genes encoding defense proteins, and genes encoding a tobacco systemin and the allene oxide Cyclase, an enzyme in JA biosynthesis. Furthermore, the accumulation of NICTABA was quantified after S. littoralis herbivory and immunofluorescence microscopy was used to study the localization of NICTABA in the tobacco leaf.
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PAMP‐induced defense responses in potato require both salicylic acid and jasmonic acid
Plant Journal, 2008Co-Authors: Vincentius A. Halim, Otto Miersch, Lennart Eschen-lippold, Simone Altmann, Dorothea Ellinger, Dierk Scheel, Sabine RosahlAbstract:Summary To elucidate the molecular mechanisms underlying pathogen-associated molecular pattern (PAMP)-induced defense responses in potato (Solanum tuberosum), the role of the signaling compounds salicylic acid (SA) and jasmonic acid (JA) was analyzed. Pep-13, a PAMP from Phytophthora, induces the accumulation of SA, JA and hydrogen peroxide, as well as the activation of defense genes and hypersensitive-like cell death. We have previously shown that SA is required for Pep-13-induced defense responses. To assess the importance of JA, RNA interference constructs targeted at the JA biosynthetic genes, allene oxide Cyclase and 12-oxophytodienoic acid reductase, were expressed in transgenic potato plants. In addition, expression of the F-box protein COI1 was reduced by RNA interference. Plants expressing the RNA interference constructs failed to accumulate the respective transcripts in response to wounding or Pep-13 treatment, neither did they contain significant amounts of JA after elicitation. In response to infiltration of Pep-13, the transgenic plants exhibited a highly reduced accumulation of reactive oxygen species as well as reduced hypersensitive cell death. The ability of the JA-deficient plants to accumulate SA suggests that SA accumulation is independent or upstream of JA accumulation. These data show that PAMP responses in potato require both SA and JA and that, in contrast to Arabidopsis, these compounds act in the same signal transduction pathway. Despite their inability to fully respond to PAMP treatment, the transgenic RNA interference plants are not altered in their basal defense against Phytophthora infestans.
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The AOC promoter of tomato is regulated by developmental and environmental stimuli.
Phytochemistry, 2008Co-Authors: Irene Stenzel, Bettina Hause, Otto Miersch, Reinhard K. Proels, Thomas Roitsch, Claus WasternackAbstract:The allene oxide Cyclase (AOC) catalyzes the formation of cis-(+)-12-oxophytodienoic acid, an intermediate in jasmonate biosynthesis and is encoded by a single copy gene in tomato. The full length AOC promoter isolated by genome walk contains 3600 bp. Transgenic tomato lines carrying a 1000 bp promoter fragment and the full length promoter, respectively, in front of the β-glucuronidase (GUS)-encoding uidA gene and several tobacco lines carrying the full length tomato AOC promoter before GUS were used to record organ- and tissue-specific promoter activities during development and in response to various stimuli. High promoter activities corresponding to immunocytochemically detected occurrence of the AOC protein were found in seeds and young seedlings and were confined to the root tip, hypocotyl and cotyledons of 3-d-old seedlings. In 10-d-old seedlings promoter activity appeared preferentially in the elongation zone. Fully developed tomato leaves were free of AOC promoter activity, but showed high activity upon wounding locally and systemically or upon treatment with JA, systemin or glucose. Tomato flowers showed high AOC promoter activities in ovules, sepals, anthers and pollen. Most of the promoter activity patterns found in tomato with the 1000 bp promoter fragment were also detected with the full length tomato AOC promoter in tobacco during development or in response to various stimuli. The data support a spatial and temporal regulation of JA biosynthesis during development and in response to environmental stimuli.
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Expression of allene oxide Cyclase and accumulation of jasmonates during organogenic nodule formation from hop (Humulus lupulus var. Nugget) internodes
Plant and Cell Physiology, 2005Co-Authors: Ana Margarida Fortes, Claus Wasternack, Otto Miersch, Peter R. Lange, Rui Malhó, Pilar S. Testillano, María Carmen Risueño, Maria Salomé PaisAbstract:;A crucial step in the biosynthesis of jasmonic acid (JA) is the formation of its stereoisomeric precursor, cis-(+)-12oxophytodienoic acid (OPDA), which is catalyzed by allene oxide Cyclase (AOC, EC 5.3.99.6). A cDNA of AOC was isolated from Humulus lupulus var. Nugget. The ORF of 765 bp encodes a 255 amino acid protein, which carries a putative chloroplast targeting sequence. The recombinant protein without its putative chloroplast target sequence showed significant AOC activity. Previously we demonstrated that wounding induces organogenic nodule formation in hop. Here we show that the AOC transcript level increases in response to wounding of internodes, peaking between 2 and 4 h after wounding. In addition, Western blot analysis showed elevated levels of AOC peaking 24 h after internode inoculation. The AOC increase was accompanied by increased JA levels 24 h after wounding, whereas OPDA had already reached its highest level after 12 h. AOC is mostly present in the vascular bundles of inoculated internodes. During prenodule and nodule formation, AOC levels were still high. JA and OPDA levels decreased down to 10 and 118 pmol (g FW) –1 , respectively, during nodule formation, but increased during plantlet regeneration. Double immunolocalization analysis of AOC and Rubisco in connection with lugol staining showed that AOC is present in amyloplasts of prenodular cells and in the chloroplasts of vacuolated nodular cells, whereas meristematic cells accumulated little AOC. These data suggest a role of AOC and jasmonates in organogenic nodule formation and plantlet regeneration from these nodules.
Kosaku Takahashi - One of the best experts on this subject based on the ideXlab platform.
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Biosynthesis and in vitro enzymatic synthesis of the isoleucine conjugate of 12-oxo-phytodienoic acid from the isoleucine conjugate of α-linolenic acid
Bioorganic & Medicinal Chemistry Letters, 2018Co-Authors: Akira Uchiyama, Hideyuki Matsuura, Takaomi Yaguchi, Hiroyuki Nakagawa, Kento Sasaki, Naoshige Kuwata, Kosaku TakahashiAbstract:Abstract The isoleucine conjugate of 12-oxo-phytodienoic acid (OPDA-Ile), a new member of the jasmonate family, was recently identified in Arabidopsis thaliana and might be a signaling molecule in plants. However, the biosynthesis and function of OPDA-Ile remains elusive. This study reports an in vitro enzymatic method for synthesizing OPDA-Ile, which is catalyzed by reactions of lipoxygenase (LOX), allene oxide synthase (AOS), and allene oxide Cyclase (AOC) using isoleucine conjugates of α -linolenic acid (LA-Ile) as the substrate. A. thaliana fed LA-Ile exhibited a marked increase in the OPDA-Ile concentration. LA-Ile was also detected in A. thaliana. Furthermore, stable isotope labelled LA-Ile was incorporated into OPDA-Ile. Thus, OPDA-Ile is biosynthesized via the cyclization of LA-Ile in A. thaliana.
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Identification of Jasmonic Acid and Jasmonoyl-Isoleucine, and Characterization of AOS, AOC, OPR and JAR1 in the Model Lycophyte Selaginella moellendorffii
Plant and Cell Physiology, 2017Co-Authors: Putri Pratiwi, Tomohiro Takahashi, Hideyuki Matsuura, Genta Tanaka, Koichi Yoneyama, Kosaku TakahashiAbstract:Jasmonic acid (JA) is involved in a variety of physiological responses in seed plants. However, the detection and role of JA in lycophytes, a group of seedless vascular plants, have remained elusive until recently. This study provides the first evidence of 12-oxo-phytodienoic acid (OPDA), JA and jasmonoyl-isoleucine (JA-Ile) in the model lycophyte Selaginella moellendorffii. Mechanical wounding stimulated the accumulation of OPDA, JA and JA-Ile. These data were corroborated by the detection of enzymatically active allene oxide synthase (AOS), allene oxide Cyclase (AOC), 12-oxo-phytodienoic acid reductase 3 (OPR3) and JA-Ile synthase (JAR1) in S. moellendorffii. SmAOS2 is involved in the first committed step of JA biosynthesis. SmAOC1 is a crucial enzyme for generating the basic structure of jasmonates and is actively involved in the formation of OPDA. SmOPR5, a functionally active OPR3-like enzyme, is also vital for the reduction of (+)-cis-OPDA, the only isomer of the JA precursor. The conjugation of JA to Ile by SmJAR1 demonstrates that S. moellendorffii produces JA-Ile. Thus, the four active enzymes have characteristics similar to those in seed plants. Wounding and JA treatment induced the expression of SmAOC1 and SmOPR5. Furthermore, JA inhibited the growth of shoots in S. moellendorffii, which suggests that JA functions as a signaling molecule in S. moellendorffii. This study proposes that JA evolved as a plant hormone for stress adaptation, beginning with the emergence of vascular plants.
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Functional analysis of allene oxide Cyclase, MpAOC, in the liverwort Marchantia polymorpha
Phytochemistry, 2015Co-Authors: Yusuke Yamamoto, Jun Ohshika, Tomohiro Takahashi, Kimitsune Ishizaki, Takayuki Kohchi, Hideyuki Matusuura, Kosaku TakahashiAbstract:12-Oxo-phytodienoic acid (OPDA) is an intermediate in jasmonic acid (JA) biosynthesis. OPDA exerts JA-dependent and JA-independent biological effects; therefore, it is considered a signaling molecule in flowering plants. OPDA is induced by bacterial infection and wounding and inhibits growth in the moss Physcomitrella patens. The functions of OPDA and allene oxide Cyclase (AOC) in the liverwort Marchantia polymorpha were explored, which represents the most basal lineage of extant land plants. The analysis of OPDA showed that it is present in M. polymorpha and is increased by wounding. OPDA has been suggested to be involved in the response to environmental stresses. Moreover, OPDA showed growth inhibitory activity in M. polymorpha. Nonetheless JA in M. polymorpha was not found in this study. AOC synthesizes OPDA from an unstable allene oxide. A database search of the M. polymorpha genome identified only a putative gene encoding allene oxide Cyclase (MpAOC). Recombinant MpAOC showed AOC activity similar to that in flowering plants. MpAOC was localized to chloroplasts, as in flowering plants. Expression of MpAOC was induced by wounding and OPDA treatment, and positive feedback regulation of OPDA was demonstrated in M. polymorpha. Overexpression of MpAOC increased the endogenous OPDA level and suppressed growth in M. polymorpha. These results indicate the role of OPDA as a signaling molecule regulating growth and the response to wounding in the liverwort M. polymorpha.
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Proteomic analysis of Physcomitrella patens treated with 12-oxo-phytodienoic acid, an important oxylipin in plants
Bioscience Biotechnology and Biochemistry, 2014Co-Authors: Erika Toshima, Hideyuki Matsuura, Yohei Nanjo, Setsuko Komatsu, Kosaku TakahashiAbstract:12-Oxo-phytodienoic acid (OPDA) is biosynthesized in the octadecanoid pathway and is considered to be a signaling molecule in plants. In Physcomitrella patens, OPDA is induced by bacterial infection and mechanical stress and is known to suppress growth; however, the functional mechanism of OPDA signaling remains elusive. In this study, we performed a proteomic analysis of P. patens treated with OPDA and found that the expression of 82 proteins was significantly altered, with approximately 80% of these proteins being downregulated by OPDA. The identified proteins were mainly categorized as being involved in photosynthesis, metabolism, and protein synthesis, and most of the proteins that were upregulated by OPDA are involved in light-dependent reactions, suggesting that OPDA regulates a function in chloroplasts. Additionally, OPDA induced the expression of an allene oxide Cyclase (PpAOC1) in the octadecanoid pathway, demonstrating positive feedback regulation by OPDA in P. patens.
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Efficient synthesis of (+)-cis-12-oxo-phytodienoic acid by an in vitro enzymatic reaction.
Bioscience Biotechnology and Biochemistry, 2012Co-Authors: Akiyuki Kajiwara, Takahiro Hashimoto, Hideyuki Matsuura, Kosaku TakahashiAbstract:12-Oxo-phytodienoic acid (OPDA) is an important metabolite on the octadecanoid pathway of plants. This study shows an efficient in vitro synthesis of (+)-cis-OPDA by using a flaxseed extract and an allene oxide Cyclase. The OPDA yield of the reaction in this study was almost 7-fold higher than that in the conventional reaction with the flaxseed extract.
Irene Stenzel - One of the best experts on this subject based on the ideXlab platform.
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Molecular Cloning of Allene Oxide Cyclase
2020Co-Authors: Irene Stenzel, Bettina Hause, Helmut Maucher, Mats Hamberg, Rudi Grimm, Martin Ganali, Claus Dr. WasternackAbstract:)-phytodienoic acid, the ultimateprecursor of jasmonic acid. This dimeric enzyme haspreviously been purified, and two almost identical N-terminal peptides were found, suggesting allene oxideCyclase to be a homodimeric protein. Furthermore, thenative protein was N-terminally processed. Using de-generate primers, a polymerase chain reaction fragmentcould be generated from tomato, which was further usedto isolate a full-length cDNA clone of 1 kilobase paircoding for a protein of 245 amino acids with a molecularmass of 26 kDa. Whereas expression of the whole codingregion failed to detect allene oxide Cyclase activity, a5
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ALLENE OXIDE Cyclase (AOC) gene family members of Arabidopsis thaliana: tissue- and organ-specific promoter activities and in vivo heteromerization*
Journal of Experimental Botany, 2012Co-Authors: Irene Stenzel, Bettina Hause, Otto Miersch, Markus Otto, Carolin Delker, Nils Kirmse, Diana Schmidt, Claus WasternackAbstract:Jasmonates are important signals in plant stress responses and plant development. An essential step in the biosynthesis of jasmonic acid (JA) is catalysed by ALLENE OXIDE Cyclase (AOC) which establishes the naturally occurring enantiomeric structure of jasmonates. In Arabidopsis thaliana, four genes encode four functional AOC polypeptides (AOC1, AOC2, AOC3, and AOC4) raising the question of functional redundancy or diversification. Analysis of transcript accumulation revealed an organ-specific expression pattern, whereas detailed inspection of transgenic lines expressing the GUS reporter gene under the control of individual AOC promoters showed partially redundant promoter activities during development: (i) In fully developed leaves, promoter activities of AOC1, AOC2, and AOC3 appeared throughout all leaf tissue, but AOC4 promoter activity was vascular bundle-specific; (ii) only AOC3 and AOC4 showed promoter activities in roots; and (iii) partially specific promoter activities were found for AOC1 and AOC4 in flower development. In situ hybridization of flower stalks confirmed the GUS activity data. Characterization of single and double AOC loss-of-function mutants further corroborates the hypothesis of functional redundancies among individual AOCs due to a lack of phenotypes indicative of JA deficiency (e.g. male sterility). To elucidate whether redundant AOC expression might contribute to regulation on AOC activity level, protein interaction studies using bimolecular fluorescence complementation (BiFC) were performed and showed that all AOCs can interact among each other. The data suggest a putative regulatory mechanism of temporal and spatial fine-tuning in JA formation by differential expression and via possible heteromerization of the four AOCs.
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The AOC promoter of tomato is regulated by developmental and environmental stimuli.
Phytochemistry, 2008Co-Authors: Irene Stenzel, Bettina Hause, Otto Miersch, Reinhard K. Proels, Thomas Roitsch, Claus WasternackAbstract:The allene oxide Cyclase (AOC) catalyzes the formation of cis-(+)-12-oxophytodienoic acid, an intermediate in jasmonate biosynthesis and is encoded by a single copy gene in tomato. The full length AOC promoter isolated by genome walk contains 3600 bp. Transgenic tomato lines carrying a 1000 bp promoter fragment and the full length promoter, respectively, in front of the β-glucuronidase (GUS)-encoding uidA gene and several tobacco lines carrying the full length tomato AOC promoter before GUS were used to record organ- and tissue-specific promoter activities during development and in response to various stimuli. High promoter activities corresponding to immunocytochemically detected occurrence of the AOC protein were found in seeds and young seedlings and were confined to the root tip, hypocotyl and cotyledons of 3-d-old seedlings. In 10-d-old seedlings promoter activity appeared preferentially in the elongation zone. Fully developed tomato leaves were free of AOC promoter activity, but showed high activity upon wounding locally and systemically or upon treatment with JA, systemin or glucose. Tomato flowers showed high AOC promoter activities in ovules, sepals, anthers and pollen. Most of the promoter activity patterns found in tomato with the 1000 bp promoter fragment were also detected with the full length tomato AOC promoter in tobacco during development or in response to various stimuli. The data support a spatial and temporal regulation of JA biosynthesis during development and in response to environmental stimuli.
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Suppression of Allene Oxide Cyclase in Hairy Roots of Medicago truncatula Reduces Jasmonate Levels and the Degree of Mycorrhization with Glomus intraradices
Plant Physiology, 2005Co-Authors: Stanislav Isayenkov, Irene Stenzel, Cornelia Mrosk, Dieter Strack, Bettina HauseAbstract:During the symbiotic interaction between Medicago truncatula and the arbuscular mycorrhizal (AM) fungus Glomus intraradices, an endogenous increase in jasmonic acid (JA) occurs. Two full-length cDNAs coding for the JA-biosynthetic enzyme allene oxide Cyclase (AOC) from M. truncatula, designated as MtAOC1 and MtAOC2, were cloned and characterized. The AOC protein was localized in plastids and found to occur constitutively in all vascular tissues of M. truncatula. In leaves and roots, MtAOCs are expressed upon JA application. Enhanced expression was also observed during mycorrhization with G. intraradices. A partial suppression of MtAOC expression was achieved in roots following transformation with Agrobacterium rhizogenes harboring the MtAOC1 cDNA in the antisense direction under control of the cauliflower mosaic virus 35S promoter. In comparison to samples transformed with 35S∷uidA, roots with suppressed MtAOC1 expression exhibited lower JA levels and a remarkable delay in the process of colonization with G. intraradices. Both the mycorrhization rate, quantified by fungal rRNA, and the arbuscule formation, analyzed by the expression level of the AM-specific gene MtPT4, were affected. Staining of fungal material in roots with suppressed MtAOC1 revealed a decreased number of arbuscules, but these did not exhibit an altered structure. Our results indicate a crucial role for JA in the establishment of AM symbiosis.
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The allene oxide Cyclase of barley (Hordeum vulgare L.)-cloning and organ-specific expression
Phytochemistry, 2004Co-Authors: Helmut Maucher, Bettina Hause, Irene Stenzel, Otto Miersch, Niels Stein, Manoj Prasad, Uwe Zierold, Patrick Schweizer, Conrad Dorer, Claus WasternackAbstract:Abstract The naturally occurring enantiomer of the various octadecanoids and jasmonates is established in a biosynthetic step catalyzed by the allene oxide Cyclase (AOC). The AOC converts an allene oxide formed by an allene oxide synthase (AOS). Here, we show cloning and characterization of cDNAs encoding the AOC and a third AOS, respectively, in addition to the two AOSs previously published (Plant J. 21, 199–213, 2000). The ORF of the AOC-cDNA of 717 bp codes for a protein of 238 amino acid residues carrying a putative chloroplast target sequence. Overexpression without chloroplast target sequence revealed AOC activity. The AOC was found to be a single copy gene which mapped on chromosome 6H. AOC mRNA accumulation appeared in leaf segments upon treatment with various jasmonates, octadecanoids and ABA or during stress such as treatment with sorbitol or glucose solutions. Infection with powdery mildew activated AOC expression in susceptible and resistant lines of barley which correlated with PR1b expression. Among different tissues of barley seedlings, the scutellar node and leaf base accumulated AOC mRNA preferentially which correlated with accumulation of mRNAs for other biosynthetic enzymes (lipoxygenases, AOSs). AOC mRNA accumulation appeared also abundantly in parts of the root containing the tip and correlated with elevated levels of jasmonates. The data suggest a link of AOC expression and JA formation and support role of JA in stress responses and development of barley.