Interrelationships between mutualistic endophytic microorganisms, the root-knot nematode Meloidogyne incognita and the sap-sucking insect Aphis gossypii on tomato, squash and Arabidopsis
Interrelationships between mutualistic endophytic microorganisms, the root-knot nematode Meloidogyne incognita and the sap-sucking insect Aphis gossypii on tomato, squash and Arabidopsis
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DissertationDate of Exam
16.01.2012Date of Publication
02.02.2012Advisor
Sikora, Richard A.Co-Referee
Goldbach, Heiner E.Metadata
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Abstract
The effects of single and combined applications of three endophytic microorganisms on the biocontrol of the root-knot nematode Meloidogyne incognita and the sap-sucking insect Aphis gossypii in tomato, squash and Arabidopsis were investigated. The studied endophytes were the fungus Fusarium oxysporum strain Fo162 (Fo162), the mycorrhiza fungus Glomus intraradices strain 510 (AMF) and the bacterium Rhizobium etli strain G12 (G12). In addition, factors that can negatively affect the interrelationships between the endophytic microorganisms in relation to their biocontrol activity were studied. Greenhouse experiments were conducted to investigate the biological control of M. incognita in tomato by single or combined applications of Fo162, AMF and G12. The individual application of each of the biocontrol agents resulted in a significant reduction in the number of M. incognita that penetrated into tomato roots. However, concomitant enhancement with Fo162 together with AMF or with G12 did not improve the reduction of M. incognita penetration. Triple-split-root experiments showed that the simultaneous, but spatially separated inoculation of both Fo162 and G12, also did not lead to a significant increase in the reduction of M. incognita penetration, when compared to the individual inoculation. In these experiments a reduction in Fo162 colonization also was observed, demonstrating that the growth of the antagonistic fungus can be systemically inhibited by the bacterium. Other experiments demonstrated that Fo162 and G12 root colonization restrained M. incognita development when the two organisms are present in the same root system. Greenhouse experiments were performed to study the biocontrol of A. gossypii in squash by single or combined applications of Fo162, AMF or G12. A small level of biological control activity toward A. gossypii was observed when the insects were exposed to squash plants inoculated with AMF. Conversely, Fo162 and G12 when present alone reduced significantly the population development of A. gossypii on squash. However, there was no evidence of a synergistic interaction toward the aphid when Fo162 together with AMF or with G12 were inoculated simultaneously to squash. Split-root experiments showed that the simultaneous, but spatially separated inoculation of both Fo162 and G12 did not improve the biocontrol of A. gossypii. In vivo and in vitro experiments were conducted to investigate the interrelationships between Fo162 and G12. The combined application, onto the same root system, of both Fo162 and G12 showed a significant reduction in tomato root colonization by Fo162. Moreover, the simultaneous but spatially separated inoculation of both endophytes, in a split-root system, resulted again in a reduction in Fo162 colonization, indicating that the growth of the fungus can be systemically inhibited by the bacterium. Antibiosis tests indicated that there was a reduction in radial growth of Fo162, when challenged with G12. In vivo and in vitro trails were then conducted on Arabidopsis to study the interrelationship between Fo162 and M. incognita. Results indicated that Fo162 was able to effectively colonize the Arabidopsis root system. Fo162 treatment resulted in a significant reduction in the number of M. incognita that penetrated into Arabidopsis roots. Split-root Arabidopsis experiments also demonstrated that Fo162 was able to systemically reduce M. incognita number of galls. Moreover, the colonization of Arabidopsis roots by Fo162 caused distinct plant growth enhancement activity. The results obtained demonstrated that the combination of “Arabidopsis-Fo162-M. incognita” could be used as a model system to elucidate the molecular basis of the interactions of these three organisms. Interaktion zwischen mutualistischen endophytischen Mikroorganismen, der Wurzelgallennematode Meloidogyne incognita und dem Phloem-saugenden Insekt Aphis gossypii an Tomate, Zucchini und Arabidopsis
In der vorliegenden Arbeit wurden Einzel- und Kombinationsanwendungen endophytischer Mikroorganismen auf ihre biologische Kontrollaktivität gegenüber des Wurzelgallennematode Meloidogyne incognita und dem Phloem-saugenden Insekt Aphis gossypii an Tomate, Zucchini und Arabidopsis untersucht.
Die untersuchten Endophyten waren der Ascomycet Fusarium oxysporum Fo162 (Fo162), der Mycorrhizapilz Glomus intraradices 510 (AMF) und das Bakterium Rhizobium etli G12 (G12). Zusätzlich wurden Faktoren untersucht, die die Wechselbeziehung zwischen den genannten Endophyten und ihrer biologische Kontrollaktivität negativ beeinflussen können. Biologische Kontrolle von Einzel- und Kombinationsanwendung von Fo162, AMF und G12 gegenüber M.incognita an Tomatenpflanzen wurden in Gewaechshausexperimenten untersucht.
Einzel Anwendung der jeweiligen Endophyten, resultierte in einer signifikanten Verringerung des Eindringens von M. incognita in Tomatenwurzeln. Kombinierte Anwendung hatte jedoch keinen synergistischen Effekt auf die Biokontrolle gegenüber M. incognita. Auch eine räumliche Trennung der Endophyten in Triple Split-Wurzelexperimenten zeigten keinen synergistischen biokontroll Effekt gegenüber M. incognita. Jedoch, wird die Fo162 Kolonisierung an Tomatenwurzeln durch G12 systemisch signifikant reduziert.
Gewächshausexperimente wurden durchgeführt, um das biologische Verhalten von A. gossypii an Zucchini bei Einzel- und Kombinationsinokulation von Fo162, AMF, G12 zu untersuchen. Ein geringe biologische Kontrollaktivität konnte mit AMF gegen A. gossypii an Zucchini beobachtet werden. Fo162 und G12 hingegen konnten beide die Populationsentwicklung von A. gossypii signifikant reduzieren. Es gab jedoch keinen Nachweis für einen synergetischen Effekt durch eine kombinierte Applikation von Fo162 mit AMF oder G12. Split-Wurzel Experimente haben gezeigt, dass gleichzeitig aber räumlich voneinander getrennte Inokulation von Fo162 und G12 ebenfalls keinen synergetischen Effekt gegenüber A. gossypii hat.
Antibiosistest haben gezeigt, dass G12 das radiale Wachstum von Fo162 signifikant inhibiert. Die Ergebnisse demonstrieren, dass in Co-inoculations Strategien mit Fo162 und G12 auch die mikrobiellen Interaktionen berücksichtigt werden sollte. In vivo und in vitro Experimente wurden mit Fo162, Arabidopsis und M.incognita durchgeführt. Fo162 ist in der Lage das Wurzelsystem von Arabidopsis zu kolonisieren und resultierte in einer signifikanten Reduzierung von penetrierenden M. incognita. Split-Wurzel Experimente mit Arabidopsis zeigen, dass Fo12 die Anzahl an Gallen systemisch reduzieren kann. Darüber hinaus zeigten Fo162-kolonisierte Arabidopsis pflanzen einen characteristischen Phänotyp. Die Ergebnisse zeigen, dass Arabidopsis-Fo162-M. incognita als Modelsystem für Interaktionen zwischen der mutualistische Endophyt Fo162 und M. incognita genutzt werden könnte.
In der vorliegenden Arbeit wurden Einzel- und Kombinationsanwendungen endophytischer Mikroorganismen auf ihre biologische Kontrollaktivität gegenüber des Wurzelgallennematode Meloidogyne incognita und dem Phloem-saugenden Insekt Aphis gossypii an Tomate, Zucchini und Arabidopsis untersucht.
Die untersuchten Endophyten waren der Ascomycet Fusarium oxysporum Fo162 (Fo162), der Mycorrhizapilz Glomus intraradices 510 (AMF) und das Bakterium Rhizobium etli G12 (G12). Zusätzlich wurden Faktoren untersucht, die die Wechselbeziehung zwischen den genannten Endophyten und ihrer biologische Kontrollaktivität negativ beeinflussen können. Biologische Kontrolle von Einzel- und Kombinationsanwendung von Fo162, AMF und G12 gegenüber M.incognita an Tomatenpflanzen wurden in Gewaechshausexperimenten untersucht.
Einzel Anwendung der jeweiligen Endophyten, resultierte in einer signifikanten Verringerung des Eindringens von M. incognita in Tomatenwurzeln. Kombinierte Anwendung hatte jedoch keinen synergistischen Effekt auf die Biokontrolle gegenüber M. incognita. Auch eine räumliche Trennung der Endophyten in Triple Split-Wurzelexperimenten zeigten keinen synergistischen biokontroll Effekt gegenüber M. incognita. Jedoch, wird die Fo162 Kolonisierung an Tomatenwurzeln durch G12 systemisch signifikant reduziert.
Gewächshausexperimente wurden durchgeführt, um das biologische Verhalten von A. gossypii an Zucchini bei Einzel- und Kombinationsinokulation von Fo162, AMF, G12 zu untersuchen. Ein geringe biologische Kontrollaktivität konnte mit AMF gegen A. gossypii an Zucchini beobachtet werden. Fo162 und G12 hingegen konnten beide die Populationsentwicklung von A. gossypii signifikant reduzieren. Es gab jedoch keinen Nachweis für einen synergetischen Effekt durch eine kombinierte Applikation von Fo162 mit AMF oder G12. Split-Wurzel Experimente haben gezeigt, dass gleichzeitig aber räumlich voneinander getrennte Inokulation von Fo162 und G12 ebenfalls keinen synergetischen Effekt gegenüber A. gossypii hat.
Antibiosistest haben gezeigt, dass G12 das radiale Wachstum von Fo162 signifikant inhibiert. Die Ergebnisse demonstrieren, dass in Co-inoculations Strategien mit Fo162 und G12 auch die mikrobiellen Interaktionen berücksichtigt werden sollte. In vivo und in vitro Experimente wurden mit Fo162, Arabidopsis und M.incognita durchgeführt. Fo162 ist in der Lage das Wurzelsystem von Arabidopsis zu kolonisieren und resultierte in einer signifikanten Reduzierung von penetrierenden M. incognita. Split-Wurzel Experimente mit Arabidopsis zeigen, dass Fo12 die Anzahl an Gallen systemisch reduzieren kann. Darüber hinaus zeigten Fo162-kolonisierte Arabidopsis pflanzen einen characteristischen Phänotyp. Die Ergebnisse zeigen, dass Arabidopsis-Fo162-M. incognita als Modelsystem für Interaktionen zwischen der mutualistische Endophyt Fo162 und M. incognita genutzt werden könnte.
Subjects
Endophyt, Biokontrolle, Nematode, Fusarium, Rhizobium, Endophyte, Biocontrol
Classification (DDC)
630 Landwirtschaft, VeterinärmedizinMartinuz Guerrero, Alfonso P.: Interrelationships between mutualistic endophytic microorganisms, the root-knot nematode Meloidogyne incognita and the sap-sucking insect Aphis gossypii on tomato, squash and Arabidopsis. - Bonn, 2012. - Dissertation, Rheinische Friedrich-Wilhelms-Universität Bonn.
Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5n-27638
Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5n-27638
@phdthesis{handle:20.500.11811/5095,
urn: https://nbn-resolving.org/urn:nbn:de:hbz:5n-27638,
author = {{Alfonso P. Martinuz Guerrero}},
title = {Interrelationships between mutualistic endophytic microorganisms, the root-knot nematode Meloidogyne incognita and the sap-sucking insect Aphis gossypii on tomato, squash and Arabidopsis},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2012,
month = feb,
note = {The effects of single and combined applications of three endophytic microorganisms on the biocontrol of the root-knot nematode Meloidogyne incognita and the sap-sucking insect Aphis gossypii in tomato, squash and Arabidopsis were investigated. The studied endophytes were the fungus Fusarium oxysporum strain Fo162 (Fo162), the mycorrhiza fungus Glomus intraradices strain 510 (AMF) and the bacterium Rhizobium etli strain G12 (G12). In addition, factors that can negatively affect the interrelationships between the endophytic microorganisms in relation to their biocontrol activity were studied. Greenhouse experiments were conducted to investigate the biological control of M. incognita in tomato by single or combined applications of Fo162, AMF and G12. The individual application of each of the biocontrol agents resulted in a significant reduction in the number of M. incognita that penetrated into tomato roots. However, concomitant enhancement with Fo162 together with AMF or with G12 did not improve the reduction of M. incognita penetration. Triple-split-root experiments showed that the simultaneous, but spatially separated inoculation of both Fo162 and G12, also did not lead to a significant increase in the reduction of M. incognita penetration, when compared to the individual inoculation. In these experiments a reduction in Fo162 colonization also was observed, demonstrating that the growth of the antagonistic fungus can be systemically inhibited by the bacterium. Other experiments demonstrated that Fo162 and G12 root colonization restrained M. incognita development when the two organisms are present in the same root system. Greenhouse experiments were performed to study the biocontrol of A. gossypii in squash by single or combined applications of Fo162, AMF or G12. A small level of biological control activity toward A. gossypii was observed when the insects were exposed to squash plants inoculated with AMF. Conversely, Fo162 and G12 when present alone reduced significantly the population development of A. gossypii on squash. However, there was no evidence of a synergistic interaction toward the aphid when Fo162 together with AMF or with G12 were inoculated simultaneously to squash. Split-root experiments showed that the simultaneous, but spatially separated inoculation of both Fo162 and G12 did not improve the biocontrol of A. gossypii. In vivo and in vitro experiments were conducted to investigate the interrelationships between Fo162 and G12. The combined application, onto the same root system, of both Fo162 and G12 showed a significant reduction in tomato root colonization by Fo162. Moreover, the simultaneous but spatially separated inoculation of both endophytes, in a split-root system, resulted again in a reduction in Fo162 colonization, indicating that the growth of the fungus can be systemically inhibited by the bacterium. Antibiosis tests indicated that there was a reduction in radial growth of Fo162, when challenged with G12. In vivo and in vitro trails were then conducted on Arabidopsis to study the interrelationship between Fo162 and M. incognita. Results indicated that Fo162 was able to effectively colonize the Arabidopsis root system. Fo162 treatment resulted in a significant reduction in the number of M. incognita that penetrated into Arabidopsis roots. Split-root Arabidopsis experiments also demonstrated that Fo162 was able to systemically reduce M. incognita number of galls. Moreover, the colonization of Arabidopsis roots by Fo162 caused distinct plant growth enhancement activity. The results obtained demonstrated that the combination of “Arabidopsis-Fo162-M. incognita” could be used as a model system to elucidate the molecular basis of the interactions of these three organisms.},
url = {https://hdl.handle.net/20.500.11811/5095}
}
urn: https://nbn-resolving.org/urn:nbn:de:hbz:5n-27638,
author = {{Alfonso P. Martinuz Guerrero}},
title = {Interrelationships between mutualistic endophytic microorganisms, the root-knot nematode Meloidogyne incognita and the sap-sucking insect Aphis gossypii on tomato, squash and Arabidopsis},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2012,
month = feb,
note = {The effects of single and combined applications of three endophytic microorganisms on the biocontrol of the root-knot nematode Meloidogyne incognita and the sap-sucking insect Aphis gossypii in tomato, squash and Arabidopsis were investigated. The studied endophytes were the fungus Fusarium oxysporum strain Fo162 (Fo162), the mycorrhiza fungus Glomus intraradices strain 510 (AMF) and the bacterium Rhizobium etli strain G12 (G12). In addition, factors that can negatively affect the interrelationships between the endophytic microorganisms in relation to their biocontrol activity were studied. Greenhouse experiments were conducted to investigate the biological control of M. incognita in tomato by single or combined applications of Fo162, AMF and G12. The individual application of each of the biocontrol agents resulted in a significant reduction in the number of M. incognita that penetrated into tomato roots. However, concomitant enhancement with Fo162 together with AMF or with G12 did not improve the reduction of M. incognita penetration. Triple-split-root experiments showed that the simultaneous, but spatially separated inoculation of both Fo162 and G12, also did not lead to a significant increase in the reduction of M. incognita penetration, when compared to the individual inoculation. In these experiments a reduction in Fo162 colonization also was observed, demonstrating that the growth of the antagonistic fungus can be systemically inhibited by the bacterium. Other experiments demonstrated that Fo162 and G12 root colonization restrained M. incognita development when the two organisms are present in the same root system. Greenhouse experiments were performed to study the biocontrol of A. gossypii in squash by single or combined applications of Fo162, AMF or G12. A small level of biological control activity toward A. gossypii was observed when the insects were exposed to squash plants inoculated with AMF. Conversely, Fo162 and G12 when present alone reduced significantly the population development of A. gossypii on squash. However, there was no evidence of a synergistic interaction toward the aphid when Fo162 together with AMF or with G12 were inoculated simultaneously to squash. Split-root experiments showed that the simultaneous, but spatially separated inoculation of both Fo162 and G12 did not improve the biocontrol of A. gossypii. In vivo and in vitro experiments were conducted to investigate the interrelationships between Fo162 and G12. The combined application, onto the same root system, of both Fo162 and G12 showed a significant reduction in tomato root colonization by Fo162. Moreover, the simultaneous but spatially separated inoculation of both endophytes, in a split-root system, resulted again in a reduction in Fo162 colonization, indicating that the growth of the fungus can be systemically inhibited by the bacterium. Antibiosis tests indicated that there was a reduction in radial growth of Fo162, when challenged with G12. In vivo and in vitro trails were then conducted on Arabidopsis to study the interrelationship between Fo162 and M. incognita. Results indicated that Fo162 was able to effectively colonize the Arabidopsis root system. Fo162 treatment resulted in a significant reduction in the number of M. incognita that penetrated into Arabidopsis roots. Split-root Arabidopsis experiments also demonstrated that Fo162 was able to systemically reduce M. incognita number of galls. Moreover, the colonization of Arabidopsis roots by Fo162 caused distinct plant growth enhancement activity. The results obtained demonstrated that the combination of “Arabidopsis-Fo162-M. incognita” could be used as a model system to elucidate the molecular basis of the interactions of these three organisms.},
url = {https://hdl.handle.net/20.500.11811/5095}
}
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