{"id":{"repo_id":"iastate","oai_identifier":"oai:dr.lib.iastate.edu:20.500.12876/Rwyqoxdw"},"canonical_url":"https://search.dev.ndltd.org/etd/iastate/oai:dr.lib.iastate.edu:20.500.12876/Rwyqoxdw","repository":{"repo_id":"iastate","name":"Iowa State University","base_url":"https://dr.lib.iastate.edu/server/oai/request"},"display":{"title":"Investigation of cytochrome P450s in the biosynthesis of rice phytoalexins","abstract":"Rice (Oryza sativa) has evolved a set of metabolites known as phytoalexins in response to biotic and abiotic stress factors. The rice phytoalexins almost invariably belong to the labdane-related diterpenoid (LRD) superfamily. The phytoalexins identified in rice thus far are momilactones A-E, phytocassanes A-F, oryzalides A and B, oryzalexins A-F, oryzalexin S, ent-10-oxodepressin and sakuranetin, all of which but the last two are LRDs. An important group of enzymes in diterpenoid biosynthesis are cytochromes P450 (CYPs) which catalyze various tailoring reactions on LRD olefins to produce bioactive diterpenoids. Intriguingly, two biosynthetic gene clusters (BGCs), composed of CYPs and upstream cyclases dedicated to LRD production, have been discovered in the rice genome. The chromosome two BGC (c2BGC) contains a set of closely related CYP76M sub-family members that function in LRD biosynthesis. The CYP76Ms from the c2BGC and two other closely-related sub-family members were functionally characterized. Recent data have also suggested an interdependence of these two rice BGCs in LRD biosynthesis. Here this interdependence is further elaborated upon, along with presentation of potential phytocassane and oryzalide biosynthetic networks.","abstract_html":"Rice (Oryza sativa) has evolved a set of metabolites known as phytoalexins in response to biotic and abiotic stress factors. The rice phytoalexins almost invariably belong to the labdane-related diterpenoid (LRD) superfamily. The phytoalexins identified in rice thus far are momilactones A-E, phytocassanes A-F, oryzalides A and B, oryzalexins A-F, oryzalexin S, ent-10-oxodepressin and sakuranetin, all of which but the last two are LRDs. An important group of enzymes in diterpenoid biosynthesis are cytochromes P450 (CYPs) which catalyze various tailoring reactions on LRD olefins to produce bioactive diterpenoids. Intriguingly, two biosynthetic gene clusters (BGCs), composed of CYPs and upstream cyclases dedicated to LRD production, have been discovered in the rice genome. The chromosome two BGC (c2BGC) contains a set of closely related CYP76M sub-family members that function in LRD biosynthesis. The CYP76Ms from the c2BGC and two other closely-related sub-family members were functionally characterized. Recent data have also suggested an interdependence of these two rice BGCs in LRD biosynthesis. Here this interdependence is further elaborated upon, along with presentation of potential phytocassane and oryzalide biosynthetic networks.","abstract_has_math":false,"creators":["Oyagbenro, Richard Kofi"],"institution":"Iowa State University","degree_name":"Doctor of Philosophy","degree_level":"dissertation","degree_discipline":"Biochemistry","degree_department":"Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology (LAS)","school":null,"contributors":[],"advisors":["Peters, Reuben J","Sashital, Dipali","Nelson, Scott","Shao, Zengyi","Venditti, Vincenzo"],"committee_chairs":[],"committee_members":[],"year":2022,"date_issued":"2022-05","date_published":"2022-05","updated_at":"2026-07-24T02:38:57Z","subjects":[],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.31274/td-20240329-459"],"render_values":[{"text":"https://doi.org/10.31274/td-20240329-459","href":"https://doi.org/10.31274/td-20240329-459","code":true}]}]},"links":{"outbound_url":"https://dr.lib.iastate.edu/handle/20.500.12876/Rwyqoxdw","outbound_label":"Repository record","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Peters, Reuben J","Sashital, Dipali","Nelson, Scott","Shao, Zengyi","Venditti, Vincenzo"]},{"key":"dc:contributor.department","label":"Department","values":["Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology (LAS)","Biochem, Biophysics, and Molecular Biology"]},{"key":"dc:creator","label":"Author","values":["Oyagbenro, Richard Kofi"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2022-11-09T02:42:31Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2022-11-09T02:42:31Z"]},{"key":"dc:date.issued","label":"Date","values":["2022-05"]},{"key":"dc:type","label":"Dc Type","values":["dissertation"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biochemistry"]},{"key":"thesis:degree_level","label":"Degree Level","values":["dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Iowa State University"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.31274/td-20240329-459"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://dr.lib.iastate.edu/handle/20.500.12876/Rwyqoxdw"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Rice (Oryza sativa) has evolved a set of metabolites known as phytoalexins in response to biotic and abiotic stress factors. The rice phytoalexins almost invariably belong to the labdane-related diterpenoid (LRD) superfamily. The phytoalexins identified in rice thus far are momilactones A-E, phytocassanes A-F, oryzalides A and B, oryzalexins A-F, oryzalexin S, ent-10-oxodepressin and sakuranetin, all of which but the last two are LRDs. An important group of enzymes in diterpenoid biosynthesis are cytochromes P450 (CYPs) which catalyze various tailoring reactions on LRD olefins to produce bioactive diterpenoids. Intriguingly, two biosynthetic gene clusters (BGCs), composed of CYPs and upstream cyclases dedicated to LRD production, have been discovered in the rice genome. The chromosome two BGC (c2BGC) contains a set of closely related CYP76M sub-family members that function in LRD biosynthesis. The CYP76Ms from the c2BGC and two other closely-related sub-family members were functionally characterized. Recent data have also suggested an interdependence of these two rice BGCs in LRD biosynthesis. Here this interdependence is further elaborated upon, along with presentation of potential phytocassane and oryzalide biosynthetic networks."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["PDF"]},{"key":"dc:title","label":"Title","values":["Investigation of cytochrome P450s in the biosynthesis of rice phytoalexins"]}]}],"canonical_facts":{"dc:contributor.advisor":["Peters, Reuben J","Sashital, Dipali","Nelson, Scott","Shao, Zengyi","Venditti, Vincenzo"],"dc:contributor.department":["Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology (LAS)","Biochem, Biophysics, and Molecular Biology"],"dc:creator":["Oyagbenro, Richard Kofi"],"dc:date.accessioned":["2022-11-09T02:42:31Z"],"dc:date.available":["2022-11-09T02:42:31Z"],"dc:date.issued":["2022-05"],"dc:description.abstract":["Rice (Oryza sativa) has evolved a set of metabolites known as phytoalexins in response to biotic and abiotic stress factors. The rice phytoalexins almost invariably belong to the labdane-related diterpenoid (LRD) superfamily. The phytoalexins identified in rice thus far are momilactones A-E, phytocassanes A-F, oryzalides A and B, oryzalexins A-F, oryzalexin S, ent-10-oxodepressin and sakuranetin, all of which but the last two are LRDs. An important group of enzymes in diterpenoid biosynthesis are cytochromes P450 (CYPs) which catalyze various tailoring reactions on LRD olefins to produce bioactive diterpenoids. Intriguingly, two biosynthetic gene clusters (BGCs), composed of CYPs and upstream cyclases dedicated to LRD production, have been discovered in the rice genome. The chromosome two BGC (c2BGC) contains a set of closely related CYP76M sub-family members that function in LRD biosynthesis. The CYP76Ms from the c2BGC and two other closely-related sub-family members were functionally characterized. Recent data have also suggested an interdependence of these two rice BGCs in LRD biosynthesis. Here this interdependence is further elaborated upon, along with presentation of potential phytocassane and oryzalide biosynthetic networks."],"dc:format.mimetype":["PDF"],"dc:identifier.doi":["https://doi.org/10.31274/td-20240329-459"],"dc:identifier.uri":["https://dr.lib.iastate.edu/handle/20.500.12876/Rwyqoxdw"],"dc:language.iso":["en"],"dc:title":["Investigation of cytochrome P450s in the biosynthesis of rice phytoalexins"],"dc:type":["dissertation"],"thesis:degree_discipline":["Biochemistry"],"thesis:degree_level":["dissertation"],"thesis:degree_name":["Doctor of Philosophy"],"thesis:institution_name":["Iowa State University"]},"updated_at":"2026-07-24T02:38:57Z"}