12-Oxo-Phytodienoic Acid Triggers Expression of a Distinct Set of Genes and Plays a Role in Wound-Induced Gene Expression in Arabidopsis

Abstract

Jasmonic acid (JA) and methyl jasmonate (MeJA), collectively known as JAs, regulate diverse physiological processes in plants, including the response to wounding. Recent reports suggest that a cyclopentenone precursor of JA, 12-oxo-phytodienoic acid (OPDA), can also induce gene expression. However, little is known about the physiological significance of OPDA-dependent gene expression. We used microarray analysis of approximately 21,500 Arabidopsis (Arabidopsis thaliana) genes to compare responses to JA, MeJA, and OPDA treatment. Although many genes responded identically to both OPDA and JAs, we identified a set of genes (OPDA-specific response genes [ORGs]) that specifically responded to OPDA but not to JAs. ORGs primarily encoded signaling components, transcription factors, and stress response-related genes. One-half of the ORGs were induced by wounding. Analysis using mutants deficient in the biosynthesis of JAs revealed that OPDA functions as a signaling molecule in the wounding response. Unlike signaling via JAs, OPDA signaling was CORONATINE INSENSITIVE 1 independent. These results indicate that an OPDA signaling pathway functions independently of JA/MeJA signaling and is required for the wounding response in Arabidopsis.

Safeners recruit multiple signalling pathways for the orchestrated induction of the cellular xenobiotic detoxification machinery in Arabidopsis

“…Endogenous signalling molecules formed under oxidative stress conditions have recently been identified. They include phytoprostanes and 12-oxophytodienoic acid, that is, electrophilic oxylipins derived from oxidized membrane lipids, which were shown to induce the expression of detoxification genes (Loeffler et al 2005;Taki et al 2005;Mueller et al 2008;Mueller & Berger 2009). A feature shared by safeners and oxylipins is their high degree of electrophilicity, because of the presence of a,b-unsaturated carbonyl groups or chlorine substituents.…”

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

“…15) 12-Oxo-phytodienoic acid (12-OPDA), an intermediate compound in jasmonic acid biosynthesis, also serves as a signal mediator in an overlapping but distinct way from JA. 16,17) The 9-LOX pathway has also been indicated to be involved in the defense responses of plants, particularly in local defense reactions such as hypersensitive responses. Enhanced expression of a 9-LOX gene was shown to be essential for tobacco (Nicotiana tabacum) plants in establishing incompatibility with Phytophthora parasitica.…”

OPDA-Ile – a new JA-Ile-independent signal?

“…Preferential expression of genes upon OPDA treatment such as ZAT10 or GRX480 together with about 150 genes have been postulated repeatedly, 18,26,28 and also proteomic approaches showed OPDA-specific responses. 27 In all these experiments, however, putative formation of JA upon OPDA treatment was not excluded.…”

“…26 GRX480 encodes a GLUTAREDOXIN and is regarded as candidate for an OPDAassociated transcription regulator. 18 Both genes were previously shown to be OPDA-inducible, 18,26 indicating their role as a putative marker for OPDA responses. COI1-independent expression was confirmed for GRX480, since tests with the coi1-16 mutant showed an OPDA-inducible expression of GRX480.…”

“…25 In a transcriptomic analysis following OPDA-treatment more than 150 genes were found to be preferentially up-regulated by OPDA. 26 Such transcriptomics data, indicating an OPDA-specificity, as well as proteomics data on OPDA-specific upregulated proteins, have been subsequently collected several times. 18,27,28 The reason for inactivity of OPDA in promoting interaction of COI1-JAZ1 or COI1-JAZ3 2,11 could be that -similar to JAthe conjugation with Ile is required.…”