Cyclopentenone isoprostanes induced by reactive oxygen species trigger defense gene activation and phytoalexin accumulation in plants

Abstract

SummaryLipid peroxidation may be initiated either by lipoxygenases or by reactive oxygen species (ROS). Enzymatic oxidation of a-linolenate can result in the biosynthesis of cyclic oxylipins of the jasmonate type while freeradical-catalyzed oxidation of a-linolenate may yield several classes of cyclic oxylipins termed phytoprostanes in vivo. Previously, we have shown that one of these classes, the E 1 -phytoprostanes (PPE 1 ), occurs ubiquitously in plants. In this work, it is shown that PPE 1 are converted to novel cyclopentenone A 1 -and B 1 -phytoprostanes (PPA 1 and PPB 1 ) in planta. Enhanced formation of PPE 1 , PPA 1 , and PPB 1 is observed after peroxide stress in tobacco cell cultures as well as after infection of tomato plants with a necrotrophic fungus, Botrytis cinerea. PPA 1 and PPB 1 display powerful biologic activities including activation of mitogen-activated protein kinase (MAPK) and induction of glutathione-S-transferase (GST), defense genes, and phytoalexins. Data collected so far infer that enhanced phytoprostane formation is a general consequence of oxidative stress in plants. We propose that phytoprostanes are components of an oxidant-injury-sensing, archaic signaling system that serves to induce several plant defense mechanisms.

Accumulation of 9- and 13-KODEs in response to jasmonic acid treatment and pathogenic infection in rice

“…33) The induction of stress responses by treatments with α, β-unsaturated carbonyl compounds has been reported in many other plant species. [42][43][44][45] In the present study, however, treatments with acrolein, β-ionone, 2,4-hexadienal, 2-hepten-2-one, and C 4 -C 10 aldehydes with a double bond at their α position only marginally induced sakuranetin and naringenin although 2,4-hexadienal and 2-hepten-2-one induced the accumulation of serotonin to levels close to those induced by 13-KODE treatment. The presence of an α, β-unsaturated carbonyl group in the molecular structure is therefore insufficient for the induction of defensive secondary metabolites in rice.…”

Effect of Intercropping of Angelica sinensis with Garlic on its Growth and Rhizosphere Microflora

“…1). Plants generate more reactive oxygen species (ROS) and stimulate resistance responses of plants when exposed to the stressful conditions (Thoma et al, 2003). These ROS are either toxic by-products of aerobic metabolism or regulators of growth, development and the defense pathways (Ding et al, 2007;Zhang et al, 2013).…”

Maize death acids, 9-lipoxygenase–derived cyclopente(a)nones, display activity as cytotoxic phytoalexins and transcriptional mediators

“…12-OPDA signaling is partly dependent upon TGA transcription factors that govern detoxification responses such as OPRs, glutathione S transferases (GSTs) and cytochrome P-450s (CYPs) consistent with a role in cell protection and survival (13,14). The activity of structurally related nonenzymatic cyclopentenone oxylipins, such as the phytoprostanes, overlap with 12-OPDAregulated defense responses (13,15,16). In the context of nonenzymatic lipid signals, many reactive electrophile species can promote cell protection by inducing genes responsible for detoxification, cell cycle regulation, and chaperones (17).…”