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The N icotiana attenuata GLA 1 lipase controls the accumulation of P hytophthora parasitica ‐induced oxylipins and defensive secondary metabolites
Author(s) -
SCHUCK STEFAN,
KALLENBACH MARIO,
BALDWIN IAN T.,
BONAVENTURE GUSTAVO
Publication year - 2014
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12281
Subject(s) - phenylpropanoid , oxylipin , jasmonic acid , biochemistry , biosynthesis , chemistry , biotic stress , plant defense against herbivory , biology , enzyme , salicylic acid , abiotic stress , gene
N icotiana 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 P hytophthora 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‐10 E ,12 Z ‐octadecadienoic acid (9‐ OH ‐18:2) and additional C 18 and C 19 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 GLA 1 plays a distinct role in the production of oxylipins during biotic stress responses, supplying substrates for 9‐ OH ‐18:2 and additional C 18 and C 19 oxylipin formation during P . parasitica infection, whereas supplying substrates for the biogenesis of JA during herbivory and mechanical wounding.