Intracellular Levels of Free Linolenic and Linoleic Acids Increase in Tomato Leaves in Response to Wounding

摘要: An intracellular signaling pathway for activating plant defense genes against attacking herbivores and pathogens is mediated by a lipid-based signal transduction cascade. In this pathway, linolenic acid (18:3) proposed to be liberated from cell membranes converted cyclopentanones that are involved in transcriptional regulation of genes, analogously prostaglandin synthesis function animals. Levels 18:3 linoleic tomato (Lycopersicon esculentum) leaves increased within 1 h when the were wounded with hemostat across main vein simulate herbivore attacks. The increase correlated time course accumulation jasmonic acid, cyclopentanone product 18:3, had previously been shown response both wounding elicitors genes. One hour after wounding, at least 15-fold excess was found over required account levels newly synthesized acid. free fatty acids control accounted less than 0.25% total acids. However, lipid contents remained relatively unchanged up 8 indicating extensive loss lipids did not occur, although gradual decrease polar observed, mainly monogalactosyl diacylglycerol chloroplast lipids. data support role release as key step events activate herbivores.