Plant defensive mechanisms against insect pests
This study has focused on testing the following two hypotheses: • Pest resistant plants have higher levels and/or several different kinds of secondary metabolites. • Induced defensive systems in resistant plants are activated more rapidly than those of susceptible plants. As a background for the...
| Autor principal: | |
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| Formato: | First cycle, G2E |
| Lenguaje: | sueco Inglés |
| Publicado: |
2012
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| Materias: | |
| Acceso en línea: | https://stud.epsilon.slu.se/3834/ |
| _version_ | 1855570596505583616 |
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| author | Markgren, Joel |
| author_browse | Markgren, Joel |
| author_facet | Markgren, Joel |
| author_sort | Markgren, Joel |
| collection | Epsilon Archive for Student Projects |
| description | This study has focused on testing the following two hypotheses:
• Pest resistant plants have higher levels and/or several different kinds of secondary metabolites.
• Induced defensive systems in resistant plants are activated more rapidly than those of susceptible plants.
As a background for the test of the hypotheses a short literature study was performed concerning plant defensive mechanisms in Arabidopsis thaliana. This survey describes basic defenses like trichomes, constitutive defenses like the glucosinolate-myrosinase system, which can create toxins, and inducible defenses like the JA-, ET- and SA- defenses, which result in different chemical responses. Feeding experiments with the plant A. thaliana, the generalist insect pest Spodoptera littoralis and the specialist insect pest Plutella xylostella have been conducted. The results showed that the Spodoptera generalist is greatly affected by the plant`s defensive system, while the Plutella insect is not. A qPCR analysis of LOX 2 gene expression was conducted to examine the defensive strategy of plants against attacks by Plutella, which showed that all plants except one activated their inducible defenses. A feeding experiment with primed (Bacillus amyloliquefaciens) Arabidopsis plants and Spodoptera larvae was conducted and showed that primed plants, which trigger their defenses faster, not necessarily counteract pests better than non-primed plants. |
| format | First cycle, G2E |
| id | RepoSLU3834 |
| institution | Swedish University of Agricultural Sciences |
| language | swe Inglés |
| publishDate | 2012 |
| publishDateSort | 2012 |
| record_format | eprints |
| spelling | RepoSLU38342012-04-20T14:24:49Z https://stud.epsilon.slu.se/3834/ Plant defensive mechanisms against insect pests Markgren, Joel Plant ecology Plant physiology and biochemistry Pests of plants This study has focused on testing the following two hypotheses: • Pest resistant plants have higher levels and/or several different kinds of secondary metabolites. • Induced defensive systems in resistant plants are activated more rapidly than those of susceptible plants. As a background for the test of the hypotheses a short literature study was performed concerning plant defensive mechanisms in Arabidopsis thaliana. This survey describes basic defenses like trichomes, constitutive defenses like the glucosinolate-myrosinase system, which can create toxins, and inducible defenses like the JA-, ET- and SA- defenses, which result in different chemical responses. Feeding experiments with the plant A. thaliana, the generalist insect pest Spodoptera littoralis and the specialist insect pest Plutella xylostella have been conducted. The results showed that the Spodoptera generalist is greatly affected by the plant`s defensive system, while the Plutella insect is not. A qPCR analysis of LOX 2 gene expression was conducted to examine the defensive strategy of plants against attacks by Plutella, which showed that all plants except one activated their inducible defenses. A feeding experiment with primed (Bacillus amyloliquefaciens) Arabidopsis plants and Spodoptera larvae was conducted and showed that primed plants, which trigger their defenses faster, not necessarily counteract pests better than non-primed plants. Denna studie har fokuserat på att testa två hypoteser: • Insektsresistenta växter har högre halter och/eller har flera olika sorters sekundära metaboliter. • Inducerbara försvar aktiveras snabbare i resistenta växter än i mottagliga växter. Som bakgrund till hypotesprövningen gjordes en mindre litteraturstudie om försvarsmekanismer i växten Arabidopsis thaliana, vilken beskriver grundläggande försvar som trikomer, konstitutivt försvar som glukosinolat-myrosinassystemet som kan bilda gifter och inducerbara försvar som JA-, ET- och SA- systemen som kan stimulera flera olika typer av kemiska reaktioner. Flera matningsförsök har gjorts med växten A. thaliana, generalistinsekten Spodoptera littoralis och specialistinsekten Plutella xylostella. Resultaten visade att Spodoptera påverkades starkt av växtens försvarssystem medan Plutella inte gjorde det. För att undersöka närmare hur plantorna försvarade sig mot angrepp av Plutella genomfördes en qPCR- analys för att analysera LOX 2-genens uttryck, vilket visade att alla plantor, utom en, aktiverade sina inducerbara försvar. Ett matningsförsök utfördes med primade (Bacillus amyloliquefaciens) Arabidopsis plantor och Spodoptera larver, vilket visade att primade plantor (som aktiverar sitt inducerbara försvar snabbare) inte nödvändigtvis försvarar sig bättre än icke primade plantor. 2012-01-30 First cycle, G2E NonPeerReviewed application/pdf swe https://stud.epsilon.slu.se/3834/1/markgren_j_120126.pdf Markgren, Joel, 2012. Plant defensive mechanisms against insect pests. First cycle, G2E. Uppsala: (NL, NJ) > Dept. of Plant Biology and Forest Genetics (until 131231) <https://stud.epsilon.slu.se/view/divisions/4071.html> urn:nbn:se:slu:epsilon-s-901 eng |
| spellingShingle | Plant ecology Plant physiology and biochemistry Pests of plants Markgren, Joel Plant defensive mechanisms against insect pests |
| title | Plant defensive mechanisms against insect pests |
| title_full | Plant defensive mechanisms against insect pests |
| title_fullStr | Plant defensive mechanisms against insect pests |
| title_full_unstemmed | Plant defensive mechanisms against insect pests |
| title_short | Plant defensive mechanisms against insect pests |
| title_sort | plant defensive mechanisms against insect pests |
| topic | Plant ecology Plant physiology and biochemistry Pests of plants |
| url | https://stud.epsilon.slu.se/3834/ https://stud.epsilon.slu.se/3834/ |