The 9-lipoxygenase Osr9-LOX1 interacts with the 13-lipoxygenase-mediated pathway to regulate resistance to chewing and piercing-sucking herbivores in rice

Abstract

Oxylipins produced by the 13-lipoxygenase (LOX) have been reported to play an important role in plant defense responses to herbivores. Yet, the role of oxylipins produced by the 9-LOX pathway in this process remains largely unknown. Here we cloned a gene encoding a chloroplast-localized 9-LOX, Osr9-LOX1, from rice. Transcriptional analysis revealed that herbivore infestation, mechanical wounding and jasmonic acid (JA) treatment either repressed or did not enhance the level of Osr9-LOX1 transcripts at early stages but did at later stages, whereas salicylic acid (SA) treatment quickly increased the transcript level of Osr9-LOX1. Antisense expression of Osr9-lox1 (as-r9lox1) decreased the amount of wound-induced (Z)-3-hexenal but increased levels of striped stem borer (SSB)-induced linolenic acid, JA, SA and trypsin protease inhibitors. These changes were associated with increased resistance in rice to the larvae of the SSB Chilo suppressalis. In contrast, although no significant differences were observed in the duration of the nymph stage or the number of eggs laid by female adults between the brown planthopper (BPH) Nilaparvata lugens that fed on as-r9lox1 lines and BPH that fed on wild-type (WT) rice plants, the survival rate of BPH nymphs that fed on as-r9lox1 lines was higher than that of nymphs that fed on WT plants, possibly because of a higher JA level. The results demonstrate that Osr9-LOX1 plays an important role in regulating an herbivore-induced JA burst and cross-talk between JA and SA, and in controlling resistance in rice to chewing and phloem-feeding herbivores.

Elevated CO2 differentially affects tobacco and rice defense against lepidopteran larvae via the jasmonic acid signaling pathway

“…To understand how ECO 2 affect W + OS‐induced JA and JA‐Ile, the expression levels of important genes involved in JA and JA‐Ile biosynthesis in tobacco and rice were determined. LOX ( lipoxygenase ) (Halitschke and Baldwin ; Zhou et al ) , AOS ( Allene oxide synthas e) (Halitschke et al ), AO C ( allene oxide cyclase ) (Stenzel et al ), OPR ( 12‐oxophytodienodate reductase ) (Tani et al ; Koo et al ), and JAR ( jasmonate‐resistant ) (Kang et al ; Fukumoto et al ) were selected and quantified by q‐PCR (Wasternack and Song ). In tobacco, W + S. litura OS‐induced NtLOX (1.5 h), NtAOC (0.5 h), and NtJAR (1.5 h), were 54%, 95%, and 37% elevated, respectively, under ECO 2 (Figure A, C, E), and the expression levels of NtAOS and NtOPR did not alter (Figure B, D).…”

Oxylipins from both pathogen and host antagonize jasmonic acid‐mediated defence via the 9‐lipoxygenase pathway in Fusarium verticillioides infection of maize

“…The increased substrate utilization of linolenic acid by ZmLOX3 may be a consequence of its subcellular localization. Recently, it has been reported that the rice orthologue of ZmLOX3 is plastid‐localized (Zhou et al ., ), the membranes of which are rich in linolenic acid. These results suggest that LOX3‐derived oxylipins, e.g.…”

The rice transcription factor WRKY53 suppresses herbivore-induced defenses by acting as a negative feedback modulator of map kinase activity

“…Con, Control plants. (Zhou et al, 2014) and OsNPR1 , have been described. In other plants, SA signaling and jasmonate catabolism have been shown to be involved in attenuating herbivore defenses (Pieterse and Van Loon, 2004;Campos et al, 2014).…”