Identification of flavone phytoalexins and a pathogen-inducible flavone synthase II gene (SbFNSII) in sorghum
Following inoculation with the anthracnose pathogen Colletotrichum sublineolum, seedlings of the sorghum resistant cultivar SC748-5 showed more rapid and elevated accumulation of luteolin than the susceptible cultivar BTx623. On the other hand, apigenin was the major flavone detected in infected BTx...
| Veröffentlicht in: | Journal of experimental botany. - 1985. - 61(2010), 4 vom: 29. Feb., Seite 983-94 |
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| Weitere Verfasser: | , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2010
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| Zugriff auf das übergeordnete Werk: | Journal of experimental botany |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Flavones Plant Proteins Sesquiterpenes Terpenes Cytochrome P-450 Enzyme System 9035-51-2 Phytoalexins |
| Zusammenfassung: | Following inoculation with the anthracnose pathogen Colletotrichum sublineolum, seedlings of the sorghum resistant cultivar SC748-5 showed more rapid and elevated accumulation of luteolin than the susceptible cultivar BTx623. On the other hand, apigenin was the major flavone detected in infected BTx623 seedlings. Luteolin was demonstrated to show stronger inhibition of spore germination of C. sublineolum than apigenin. Because of their pathogen-inducible and antifungal nature, both flavone aglycones are considered sorghum phytoalexins. The key enzyme responsible for flavone biosynthesis has not been characterized in monocots. A sorghum pathogen-inducible gene encoding a cytochrome P450 protein (CYP93G3) in the uncharacterized CYP93G subfamily was identified. Transgenic expression of the P450 gene in Arabidopsis demonstrated that the encoded protein is a functional flavone synthase (FNS) II in planta. The sorghum gene was then termed SbFNSII. It is a single-copy gene located on chromosome 2 and the first FNSII gene characterized in a monocot. Metabolite analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in precursor ion scan mode revealed the accumulation of 2-hydroxynaringenin and 2-hydroxyeriodictyol hexosides in the transgenic Arabidopsis plants. Hence, SbFNSII appears to share a similar catalytic mechanism with the licorice and Medicago truncatula FNSIIs (CYP93B subfamily) by converting flavanones to flavone through the formation of 2-hydroxyflavanones |
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| Beschreibung: | Date Completed 25.05.2010 Date Revised 17.03.2024 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1460-2431 |
| DOI: | 10.1093/jxb/erp364 |