The Nicotiana attenuata GLA1 lipase controls the accumulation of Phytophthora parasitica-induced oxylipins and defensive secondary metabolites.
Nicotiana attenuata plants silenced in the expression of GLYCEROLIPASE A1 (ir-gla1 plants) are compromised in the herbivore- and wound-induced accumulation of jasmonic acid (JA). However, these plants accumulate wild-type (WT) levels of JA and divinyl-ethers during Phytophthora parasitica infection. By profiling oxylipin-enriched fractions with targeted and untargeted liquid chromatography-tandem time-of-flight mass spectrometry approaches, we demonstrate that the accumulation of 9-hydroxy-10E,12Z-octadecadienoic acid (9-OH-18:2) and additional C18 and C19 oxylipins is reduced by ca. 20-fold in P. parasitica-infected ir-gla1 leaves compared with WT. This reduced accumulation of oxylipins was accompanied by a reduced accumulation of unsaturated free fatty acids and specific lysolipid species. Untargeted metabolic profiling of total leaf extracts showed that 87 metabolites accumulated differentially in leaves of P. parasitica-infected ir-gla1 plants with glycerolipids, hydroxylated-diterpene glycosides and phenylpropanoid derivatives accounting together for ca. 20% of these 87 metabolites. Thus, P. parasitica-induced oxylipins may participate in the regulation of metabolic changes during infection. Together, the results demonstrate that GLA1 plays a distinct role in the production of oxylipins during biotic stress responses, supplying substrates for 9-OH-18:2 and additional C18 and C19 oxylipin formation during P. parasitica infection, whereas supplying substrates for the biogenesis of JA during herbivory and mechanical wounding.
Department of Molecular Ecology, Max Planck Institute of Chemical Ecology, D-07745, Jena, Germany.
Stefan
S
Schuck
Mario
M
Kallenbach
Ian T
IT
Baldwin
Gustavo
G
Bonaventure
D002853:Chromatography, Liquid; D005227:Fatty Acids / Q000378:metabolism; D008049:Lipase / Q000378:metabolism*; D050356:Lipid Metabolism; D055432:Metabolomics; D054883:Oxylipins / Q000378:metabolism*; D010838:Phytophthora / Q000254:growth & development / Q000502:physiology*; D010935:Plant Diseases / Q000382:microbiology; D010936:Plant Extracts; D018515:Plant Leaves / Q000378:metabolism / Q000382:microbiology; D064210:Secondary Metabolism; D013347:Subcellular Fractions / Q000378:metabolism; D014026:Nicotiana / Q000201:enzymology* / Q000276:immunology* / Q000382:microbiology
D005227:Fatty Acids; D054883:Oxylipins; D010936:Plant Extracts; D008049:Lipase
defence; divinyl-ethers; infection; jasmonic acid; metabolism; resistance