{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/98296"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/98296","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Identification and characterization of genes in antagonism against soybean fungal pathogens by lysobacter enzymogenes","abstract":"Lysobacter enzymogenes strain C3 (LeC3) is a potential biocontrol agent for various fungal, oomycete, bacterial, and nematode plant diseases. Understanding the molecular mechanism of LeC3 antagonism against multiple pathogens could greatly improve its biocontrol efficacy. In this study, a library containing 948 transposon-insertion mutants of LeC3 was generated and screened to identify genes associated with LeC3 antagonism against fungal pathogens. Results showed that 141 mutants showed significant decrease in inhibiting hyphae growth of the white mold pathogen (Sclerotinia sclerotiorum). Among them, 74 mutants no longer inhibited S. sclerotiorum hyphae growth. The insertion sites for 50 out of these 74 mutants were determined by inverse or RATE PCR and sequencing. Nine mutants were selected for further characterization. These nine mutants were partially recovered in their abilities in inhibiting hyphae growth of the white mold pathogen by introducing plasmids containing corresponding genes. Results also showed that all nine mutants exhibited significantly decreased abilities in suppressing spore germination of the sudden death syndrome pathogen (Fusarium virguliforme), and in the production of four extracellular enzymes (protease, lipase, cellulase, and chitinase). In addition, the production of the heat stable antifungal factor (HSAF), a fungal specific antibiotic produced by LeC3, was determined in these nine mutants using HPLC and all nine mutants showed significant decrease in HSAF production or secretion. Collectively, our findings suggest that the nine genes identified and characterized in LeC3 play important roles in the antagonism against fungal pathogens probably by influencing the production and/or secretion of extracellular enzymes and HSAF.","abstract_html":"Lysobacter enzymogenes strain C3 (LeC3) is a potential biocontrol agent for various fungal, oomycete, bacterial, and nematode plant diseases. Understanding the molecular mechanism of LeC3 antagonism against multiple pathogens could greatly improve its biocontrol efficacy. In this study, a library containing 948 transposon-insertion mutants of LeC3 was generated and screened to identify genes associated with LeC3 antagonism against fungal pathogens. Results showed that 141 mutants showed significant decrease in inhibiting hyphae growth of the white mold pathogen (Sclerotinia sclerotiorum). Among them, 74 mutants no longer inhibited S. sclerotiorum hyphae growth. The insertion sites for 50 out of these 74 mutants were determined by inverse or RATE PCR and sequencing. Nine mutants were selected for further characterization. These nine mutants were partially recovered in their abilities in inhibiting hyphae growth of the white mold pathogen by introducing plasmids containing corresponding genes. Results also showed that all nine mutants exhibited significantly decreased abilities in suppressing spore germination of the sudden death syndrome pathogen (Fusarium virguliforme), and in the production of four extracellular enzymes (protease, lipase, cellulase, and chitinase). In addition, the production of the heat stable antifungal factor (HSAF), a fungal specific antibiotic produced by LeC3, was determined in these nine mutants using HPLC and all nine mutants showed significant decrease in HSAF production or secretion. Collectively, our findings suggest that the nine genes identified and characterized in LeC3 play important roles in the antagonism against fungal pathogens probably by influencing the production and/or secretion of extracellular enzymes and HSAF.","abstract_has_math":false,"creators":["Yu, Menghao"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Crop Sciences","degree_department":null,"school":null,"contributors":["Mideros, Santiago","Jamann, Tiffany","Zhao, Youfu"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2017,"date_issued":"2017-09-29T17:52:24Z","date_published":"2017-09-29T17:52:24Z","updated_at":"2026-07-22T22:24:35Z","subjects":["Lysobacter enzymogenes","Biological control","Molecular mechanism"],"languages":["en"],"rights":["Copyright 2017 Menghao Yu"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/98296","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Mideros, Santiago","Jamann, Tiffany","Zhao, Youfu"]},{"key":"dc:creator","label":"Author","values":["Yu, Menghao"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2017-09-29T17:52:24Z","2019-09-30T09:15:23Z","2017-07-17","2017-08"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Crop Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Lysobacter enzymogenes","Biological control","Molecular mechanism"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2017 Menghao Yu"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/98296"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Lysobacter enzymogenes strain C3 (LeC3) is a potential biocontrol agent for various fungal, oomycete, bacterial, and nematode plant diseases. Understanding the molecular mechanism of LeC3 antagonism against multiple pathogens could greatly improve its biocontrol efficacy. In this study, a library containing 948 transposon-insertion mutants of LeC3 was generated and screened to identify genes associated with LeC3 antagonism against fungal pathogens. Results showed that 141 mutants showed significant decrease in inhibiting hyphae growth of the white mold pathogen (Sclerotinia sclerotiorum). Among them, 74 mutants no longer inhibited S. sclerotiorum hyphae growth. The insertion sites for 50 out of these 74 mutants were determined by inverse or RATE PCR and sequencing. Nine mutants were selected for further characterization. These nine mutants were partially recovered in their abilities in inhibiting hyphae growth of the white mold pathogen by introducing plasmids containing corresponding genes. Results also showed that all nine mutants exhibited significantly decreased abilities in suppressing spore germination of the sudden death syndrome pathogen (Fusarium virguliforme), and in the production of four extracellular enzymes (protease, lipase, cellulase, and chitinase). In addition, the production of the heat stable antifungal factor (HSAF), a fungal specific antibiotic produced by LeC3, was determined in these nine mutants using HPLC and all nine mutants showed significant decrease in HSAF production or secretion. Collectively, our findings suggest that the nine genes identified and characterized in LeC3 play important roles in the antagonism against fungal pathogens probably by influencing the production and/or secretion of extracellular enzymes and HSAF.","Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2019-08-01","The student, Menghao Yu, accepted the attached license on 2017-07-17 at 11:48.","The student, Menghao Yu, submitted this Thesis for approval on 2017-07-17 at 13:26.","This Thesis was approved for publication on 2017-07-17 at 15:21.","DSpace SAF Submission Ingestion Package generated from Vireo submission #11494 on 2017-09-29 at 11:19:29","Made available in DSpace on 2017-09-29T17:52:24Z (GMT). No. of bitstreams: 2 YU-THESIS-2017.pdf: 3706174 bytes, checksum: be7cdac2d350aa26e3eda0fb4d4538c6 (MD5) LICENSE.txt: 4207 bytes, checksum: 96def288a134a80af892fd4327c1e49a (MD5) Previous issue date: 2017-07-17","Embargo set by: Colleen Fallaw for item 103504 Lift date: 2019-09-29T17:52:45Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system","Limited Restriction Lifted for Item 103504 on 2019-09-30T09:15:23Z."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Identification and characterization of genes in antagonism against soybean fungal pathogens by lysobacter enzymogenes"]}]}],"canonical_facts":{"dc:contributor":["Mideros, Santiago","Jamann, Tiffany","Zhao, Youfu"],"dc:creator":["Yu, Menghao"],"dc:date":["2017-09-29T17:52:24Z","2019-09-30T09:15:23Z","2017-07-17","2017-08"],"dc:description":["Lysobacter enzymogenes strain C3 (LeC3) is a potential biocontrol agent for various fungal, oomycete, bacterial, and nematode plant diseases. Understanding the molecular mechanism of LeC3 antagonism against multiple pathogens could greatly improve its biocontrol efficacy. In this study, a library containing 948 transposon-insertion mutants of LeC3 was generated and screened to identify genes associated with LeC3 antagonism against fungal pathogens. Results showed that 141 mutants showed significant decrease in inhibiting hyphae growth of the white mold pathogen (Sclerotinia sclerotiorum). Among them, 74 mutants no longer inhibited S. sclerotiorum hyphae growth. The insertion sites for 50 out of these 74 mutants were determined by inverse or RATE PCR and sequencing. Nine mutants were selected for further characterization. These nine mutants were partially recovered in their abilities in inhibiting hyphae growth of the white mold pathogen by introducing plasmids containing corresponding genes. Results also showed that all nine mutants exhibited significantly decreased abilities in suppressing spore germination of the sudden death syndrome pathogen (Fusarium virguliforme), and in the production of four extracellular enzymes (protease, lipase, cellulase, and chitinase). In addition, the production of the heat stable antifungal factor (HSAF), a fungal specific antibiotic produced by LeC3, was determined in these nine mutants using HPLC and all nine mutants showed significant decrease in HSAF production or secretion. Collectively, our findings suggest that the nine genes identified and characterized in LeC3 play important roles in the antagonism against fungal pathogens probably by influencing the production and/or secretion of extracellular enzymes and HSAF.","Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2019-08-01","The student, Menghao Yu, accepted the attached license on 2017-07-17 at 11:48.","The student, Menghao Yu, submitted this Thesis for approval on 2017-07-17 at 13:26.","This Thesis was approved for publication on 2017-07-17 at 15:21.","DSpace SAF Submission Ingestion Package generated from Vireo submission #11494 on 2017-09-29 at 11:19:29","Made available in DSpace on 2017-09-29T17:52:24Z (GMT). No. of bitstreams: 2 YU-THESIS-2017.pdf: 3706174 bytes, checksum: be7cdac2d350aa26e3eda0fb4d4538c6 (MD5) LICENSE.txt: 4207 bytes, checksum: 96def288a134a80af892fd4327c1e49a (MD5) Previous issue date: 2017-07-17","Embargo set by: Colleen Fallaw for item 103504 Lift date: 2019-09-29T17:52:45Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system","Limited Restriction Lifted for Item 103504 on 2019-09-30T09:15:23Z."],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/98296"],"dc:language":["en"],"dc:rights":["Copyright 2017 Menghao Yu"],"dc:subject":["Lysobacter enzymogenes","Biological control","Molecular mechanism"],"dc:title":["Identification and characterization of genes in antagonism against soybean fungal pathogens by lysobacter enzymogenes"],"dc:type":["text"],"thesis:degree_discipline":["Crop Sciences"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:35Z"}