Arabidopsis mutants of sphingolipid fatty acid α-hydroxylases accumulate ceramides and salicylates
© 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.
| Veröffentlicht in: | The New phytologist. - 1979. - 196(2012), 4 vom: 19. Dez., Seite 1086-1097 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2012
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Arabidopsis Proteins Ceramides Sphingolipids Mixed Function Oxygenases EC 1.- fatty acid 2-hydroxylase 1, Arabidopsis fatty acid 2-hydroxylase 2, Arabidopsis Salicylic Acid |
| Zusammenfassung: | © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust. In Arabidopsis, the fatty acid moiety of sphingolipids is mainly α-hydroxylated. The consequences of a reduction in this modification were analysed. Mutants of both Fatty Acid Hydroxylase genes (AtFAH1 and AtFAH2) were analysed for sphingolipid profiles. To elucidate further consequences of the mutations, metabolic analyses were performed and the influence on pathogen defence was determined. Ceramide and glucosylceramide profiles of double-mutant plants showed a reduction in sphingolipids with α-hydroxylated fatty acid moieties, and an accumulation of sphingolipids without these moieties. In addition, the free trihydroxylated long-chain bases and ceramides were increased by five- and ten-fold, respectively, whereas the amount of glucosylceramides was decreased by 25%. Metabolite analysis of the double mutant revealed salicylates as enriched metabolites. Infection experiments supported the metabolic changes, as the double mutant showed an enhanced disease-resistant phenotype for infection with the obligate biotrophic pathogen Golovinomyces cichoracearum. In summary, these results suggest that fatty acid hydroxylation of ceramides is important for the biosynthesis of complex sphingolipids. Its absence leads to the accumulation of long-chain bases and ceramides as their precursors. This increases salicylate levels and resistance towards obligate biotrophic fungal pathogens, confirming a role of sphingolipids in salicylic acid-dependent defence reactions |
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| Beschreibung: | Date Completed 25.04.2013 Date Revised 07.03.2023 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/j.1469-8137.2012.04351.x |