{"id":{"repo_id":"aachen","oai_identifier":"oai:publications.rwth-aachen.de:62318"},"canonical_url":"https://search.dev.ndltd.org/etd/aachen/oai:publications.rwth-aachen.de:62318","repository":{"repo_id":"aachen","name":"RWTH Aachen University","base_url":"https://publications.rwth-aachen.de/oai2d"},"display":{"title":"Untersuchungen zur Rolle von stress-induzierbaren Lipoxygenase-Aktivitäten in Weizen","abstract":"Lipoxygenases (LOX) catalyze the hydroperoxidation of unsaturated fatty acids. Depending upon the site of the hydroperoxy insertion LOX-isoforms are classified into a 9-LOX family and a 13-LOX family, respectively. It has been documented in a large number of earlier investigations that LOX activity increases in plants in response to pathogen attack or elicitation. This study focuses on the LOX-92 (Mr 92,000) and also on the LOX-103 (Mr 103,000) isoforms which were identified in wheat leaves in an earlier study (Bohland et al., Plant Phys. 114, 679-685, 1997). The strongly induced LOX-92, which represents more than 80 % of the LOX activity in stressed wheat leaves and which most probably is a cytosolic LOX species, has been shown to be a member of the 9-LOX family. Attempts to obtain LOX-92 protein in a sufficiently pure state to be able to obtain peptide sequence information failed due to it's extreme lability. Thus, it was not possible to clone LOX-92 by targeted PCR amplification. Northern blot analysis using a general probe for LOX sequences showed that activation of LOX-92 apparently did not occur by de novo synthesis but rather by a posttranslational mechanism. In another attempt to clone LOX-92 using degenerate probes for consensus LOX sequences, a full length wheat LOX cDNA, LOX2 Ta1 was cloned. The results indicate that LOX2 Ta1 is probably identical to LOX-103. LOX2 Ta1 (LOX-103) was further characterized by Northern blot analysis, sequence analysis, and positioning in a phylogenetic tree: (1) LOX-103 is induced by methyljasmonate and wounding at the RNA level. (2) LOX-103 is a 13-LOX species with a putative chloroplast leader sequence. (3) LOX-103 shows a close relationship to two other gramineous LOX species, the LOX2 Hv1 (Vorös et al., Eur. J. Biochem. 251, 36-44, 1998) and the LOX2 Or2 (Zabbai et al., Physiol. Mol. Plant Pathol. 64, 37-43, 2004). These species seem to play a role in induced resistance. Other aspects of this study include the identity and characteristics of LOX in wheat cell suspension cultures and also the possible existence of non-identified cell factors affecting LOX stability. The results are discussed in terms of a hypothesis in relation to other relevant work which accentuates the possible role of both the 9-LOX and 13-LOX isoforms within the intercellular signalling network determining the plant defence response.","abstract_html":"Lipoxygenases (LOX) catalyze the hydroperoxidation of unsaturated fatty acids. Depending upon the site of the hydroperoxy insertion LOX-isoforms are classified into a 9-LOX family and a 13-LOX family, respectively. It has been documented in a large number of earlier investigations that LOX activity increases in plants in response to pathogen attack or elicitation. This study focuses on the LOX-92 (Mr 92,000) and also on the LOX-103 (Mr 103,000) isoforms which were identified in wheat leaves in an earlier study (Bohland et al., Plant Phys. 114, 679-685, 1997). The strongly induced LOX-92, which represents more than 80 % of the LOX activity in stressed wheat leaves and which most probably is a cytosolic LOX species, has been shown to be a member of the 9-LOX family. Attempts to obtain LOX-92 protein in a sufficiently pure state to be able to obtain peptide sequence information failed due to it's extreme lability. Thus, it was not possible to clone LOX-92 by targeted PCR amplification. Northern blot analysis using a general probe for LOX sequences showed that activation of LOX-92 apparently did not occur by de novo synthesis but rather by a posttranslational mechanism. In another attempt to clone LOX-92 using degenerate probes for consensus LOX sequences, a full length wheat LOX cDNA, LOX2 Ta1 was cloned. The results indicate that LOX2 Ta1 is probably identical to LOX-103. LOX2 Ta1 (LOX-103) was further characterized by Northern blot analysis, sequence analysis, and positioning in a phylogenetic tree: (1) LOX-103 is induced by methyljasmonate and wounding at the RNA level. (2) LOX-103 is a 13-LOX species with a putative chloroplast leader sequence. (3) LOX-103 shows a close relationship to two other gramineous LOX species, the LOX2 Hv1 (Vorös et al., Eur. J. Biochem. 251, 36-44, 1998) and the LOX2 Or2 (Zabbai et al., Physiol. Mol. Plant Pathol. 64, 37-43, 2004). These species seem to play a role in induced resistance. Other aspects of this study include the identity and characteristics of LOX in wheat cell suspension cultures and also the possible existence of non-identified cell factors affecting LOX stability. The results are discussed in terms of a hypothesis in relation to other relevant work which accentuates the possible role of both the 9-LOX and 13-LOX isoforms within the intercellular signalling network determining the plant defence response.","abstract_has_math":false,"creators":["Seiler, Angelika"],"institution":"Publikationsserver der RWTH Aachen University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Grambow, Hans-Jürgen"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2007,"date_issued":"2007","date_published":"2007","updated_at":"2026-07-30T19:43:28Z","subjects":["info:eu-repo/classification/ddc/570","Biowissenschaften, Biologie","Weizenschwarzrost","Pathogene Pilze","Elicitor","Lipoxygenasen","cDNS","Weizen","Stress-Induktion","Wheat","Lipoxygenase"],"languages":["ger"],"rights":["info:eu-repo/semantics/openAccess"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-123892%22"],"render_values":[{"text":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-123892%22","href":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-123892%22","code":true}]}]},"links":{"outbound_url":"https://publications.rwth-aachen.de/record/62318","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Grambow, Hans-Jürgen"]},{"key":"dc:creator","label":"Author","values":["Seiler, Angelika"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:coverage","label":"Dc Coverage","values":["DE"]},{"key":"dc:date","label":"Dc Date","values":["2007"]},{"key":"dc:publisher","label":"Institution","values":["Publikationsserver der RWTH Aachen University"]},{"key":"dc:relation","label":"Dc Relation","values":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-18384"]},{"key":"dc:type","label":"Dc Type","values":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["info:eu-repo/classification/ddc/570","Biowissenschaften, Biologie","Weizenschwarzrost","Pathogene Pilze","Elicitor","Lipoxygenasen","cDNS","Weizen","Stress-Induktion","Wheat","Lipoxygenase"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["ger"]},{"key":"dc:rights","label":"Dc Rights","values":["info:eu-repo/semantics/openAccess"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/record/62318","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-123892%22"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Lipoxygenases (LOX) catalyze the hydroperoxidation of unsaturated fatty acids. Depending upon the site of the hydroperoxy insertion LOX-isoforms are classified into a 9-LOX family and a 13-LOX family, respectively. It has been documented in a large number of earlier investigations that LOX activity increases in plants in response to pathogen attack or elicitation. This study focuses on the LOX-92 (Mr 92,000) and also on the LOX-103 (Mr 103,000) isoforms which were identified in wheat leaves in an earlier study (Bohland et al., Plant Phys. 114, 679-685, 1997). The strongly induced LOX-92, which represents more than 80 % of the LOX activity in stressed wheat leaves and which most probably is a cytosolic LOX species, has been shown to be a member of the 9-LOX family. Attempts to obtain LOX-92 protein in a sufficiently pure state to be able to obtain peptide sequence information failed due to it's extreme lability. Thus, it was not possible to clone LOX-92 by targeted PCR amplification. Northern blot analysis using a general probe for LOX sequences showed that activation of LOX-92 apparently did not occur by de novo synthesis but rather by a posttranslational mechanism. In another attempt to clone LOX-92 using degenerate probes for consensus LOX sequences, a full length wheat LOX cDNA, LOX2 Ta1 was cloned. The results indicate that LOX2 Ta1 is probably identical to LOX-103. LOX2 Ta1 (LOX-103) was further characterized by Northern blot analysis, sequence analysis, and positioning in a phylogenetic tree: (1) LOX-103 is induced by methyljasmonate and wounding at the RNA level. (2) LOX-103 is a 13-LOX species with a putative chloroplast leader sequence. (3) LOX-103 shows a close relationship to two other gramineous LOX species, the LOX2 Hv1 (Vorös et al., Eur. J. Biochem. 251, 36-44, 1998) and the LOX2 Or2 (Zabbai et al., Physiol. Mol. Plant Pathol. 64, 37-43, 2004). These species seem to play a role in induced resistance. Other aspects of this study include the identity and characteristics of LOX in wheat cell suspension cultures and also the possible existence of non-identified cell factors affecting LOX stability. The results are discussed in terms of a hypothesis in relation to other relevant work which accentuates the possible role of both the 9-LOX and 13-LOX isoforms within the intercellular signalling network determining the plant defence response."]},{"key":"dc:source","label":"Dc Source","values":["Aachen : Publikationsserver der RWTH Aachen University 182 S. : Ill., graph. Darst. (2007). = Aachen, Techn. Hochsch., Diss., 2007"]},{"key":"dc:title","label":"Title","values":["Untersuchungen zur Rolle von stress-induzierbaren Lipoxygenase-Aktivitäten in Weizen"]}]}],"canonical_facts":{"dc:contributor":["Grambow, Hans-Jürgen"],"dc:coverage":["DE"],"dc:creator":["Seiler, Angelika"],"dc:date":["2007"],"dc:description":["Lipoxygenases (LOX) catalyze the hydroperoxidation of unsaturated fatty acids. Depending upon the site of the hydroperoxy insertion LOX-isoforms are classified into a 9-LOX family and a 13-LOX family, respectively. It has been documented in a large number of earlier investigations that LOX activity increases in plants in response to pathogen attack or elicitation. This study focuses on the LOX-92 (Mr 92,000) and also on the LOX-103 (Mr 103,000) isoforms which were identified in wheat leaves in an earlier study (Bohland et al., Plant Phys. 114, 679-685, 1997). The strongly induced LOX-92, which represents more than 80 % of the LOX activity in stressed wheat leaves and which most probably is a cytosolic LOX species, has been shown to be a member of the 9-LOX family. Attempts to obtain LOX-92 protein in a sufficiently pure state to be able to obtain peptide sequence information failed due to it's extreme lability. Thus, it was not possible to clone LOX-92 by targeted PCR amplification. Northern blot analysis using a general probe for LOX sequences showed that activation of LOX-92 apparently did not occur by de novo synthesis but rather by a posttranslational mechanism. In another attempt to clone LOX-92 using degenerate probes for consensus LOX sequences, a full length wheat LOX cDNA, LOX2 Ta1 was cloned. The results indicate that LOX2 Ta1 is probably identical to LOX-103. LOX2 Ta1 (LOX-103) was further characterized by Northern blot analysis, sequence analysis, and positioning in a phylogenetic tree: (1) LOX-103 is induced by methyljasmonate and wounding at the RNA level. (2) LOX-103 is a 13-LOX species with a putative chloroplast leader sequence. (3) LOX-103 shows a close relationship to two other gramineous LOX species, the LOX2 Hv1 (Vorös et al., Eur. J. Biochem. 251, 36-44, 1998) and the LOX2 Or2 (Zabbai et al., Physiol. Mol. Plant Pathol. 64, 37-43, 2004). These species seem to play a role in induced resistance. Other aspects of this study include the identity and characteristics of LOX in wheat cell suspension cultures and also the possible existence of non-identified cell factors affecting LOX stability. The results are discussed in terms of a hypothesis in relation to other relevant work which accentuates the possible role of both the 9-LOX and 13-LOX isoforms within the intercellular signalling network determining the plant defence response."],"dc:identifier":["https://publications.rwth-aachen.de/record/62318","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-123892%22"],"dc:language":["ger"],"dc:publisher":["Publikationsserver der RWTH Aachen University"],"dc:relation":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-18384"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:source":["Aachen : Publikationsserver der RWTH Aachen University 182 S. : Ill., graph. Darst. (2007). = Aachen, Techn. Hochsch., Diss., 2007"],"dc:subject":["info:eu-repo/classification/ddc/570","Biowissenschaften, Biologie","Weizenschwarzrost","Pathogene Pilze","Elicitor","Lipoxygenasen","cDNS","Weizen","Stress-Induktion","Wheat","Lipoxygenase"],"dc:title":["Untersuchungen zur Rolle von stress-induzierbaren Lipoxygenase-Aktivitäten in Weizen"],"dc:type":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]},"updated_at":"2026-07-30T19:43:28Z"}