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

Abstract

The inducible metabolites in rice leaves treated with 1 mM jasmonic acid (JA) were analyzed using HPLC. We detected an increase in the levels of two compounds, 1 and 2. Based on the comparison with mass spectra and chromatographic behavior with authentic compounds, 1 and 2 were identified as 13-oxooctadeca-9,11-dienoic acid (13-KODE) and 9-oxooctadeca-10,12-dienoic acid (9-KODE), respectively, which have not been detected in rice to date. The accumulation of these compounds was also induced by an infection by Bipolaris oryzae. Treatment of rice leaves with KODEs induced the accumulation of defensive secondary metabolites, sakuranetin, naringenin, and serotonin, suggesting that KODEs may play a role in the elicitation of defense responses. The compounds that have an α, β-unsaturated carbonyl group similar to KODEs did not reproduce the response of accumulation of defensive secondary metabolites, suggesting that additional structural factors such as long hydrophobic carbon chain are needed to elicit defense responses.

Integrated Analysis of the Transcriptome and Metabolome Revealed the Molecular Mechanisms Underlying the Enhanced Salt Tolerance of Rice Due to the Application of Exogenous Melatonin

“…For example, six genes (five LOX genes and PLA2 ) were correlated with 9-KODE, which is related to linoleic acid metabolism. Furthermore, 9-KODE, which is produced in a reaction catalyzed by LOX, is an intermediate in the jasmonic acid biosynthesis pathway ( Babenko et al, 2017 ; Nishiguchi et al, 2018 ), implying the jasmonic acid signaling pathway is involved in the melatonin-mediated salt stress response. Moreover, 13 genes (encoding nine ATs, GAT, GS, FOXRED, and PYROX) related to amino acid metabolism were highly correlated with succinic acid and three amino acids ( L -aspartic acid, glutamic acid, and L -glutamine).…”

Integration of metabolomics and existing omics data reveals new insights into phytoplasma-induced metabolic reprogramming in host plants

“…The differential fatty acids identified in the present study were all polyunsaturated (Table 2), and their roles in phytoplasma-infected plants kept unknown. Accumulation of 9-oxooctadecadienoic acid (9-KODE) was observed in rice leaves in response to jasmonic acid (JA) treatment and pathogen infection [58]. Exogenous application of 9-KODEs to rice leaves also induced accumulation of the defensive secondary metabolites such as sakuranetin, naringenin, and serotonin [58].…”

Induction of defense responses by extracts of spent mushroom substrates in rice

“…By contrast, JA and its active form jasmonoyl-L-isoleucine have been implicated in the accumulation of flavonoid phytoalexins, but not in the accumulation of diterpenoid phytoalexin. 32) The major phytoalexin in leaves treated with SMS extracts was momilactone A, and the accumulation of sakuranetin was relatively late and small. This may be a reflection of the limited contribution of the JA pathway in phy-toalexin induction in leaves treated with SMS extracts.…”

“…Thus, these oxylipins could also be regarded as DAMPs. 32) Mushroom substrates are mainly made of sawdust and the bran of rice or wheat. Mushrooms degrade these components by secreting degradation enzymes, such as peroxidase, laccase, cellulase, and glucanase during cultivation.…”