title: 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.
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Insect Sciences, Zhejiang University, Hangzhou, 310058, China; Key Laboratory for Quality Improvement of Agriculture Products of Zhejiang Province, Department of Plant Protection, Zhejiang Agriculture & Forestry University, Lin'an, 311300, China.
authors.forename: Guoxin
authors.initials: G
authors.lastname: Zhou
authors.forename: Nan
authors.initials: N
authors.lastname: Ren
authors.forename: Jingfeng
authors.initials: J
authors.lastname: Qi
authors.forename: Jing
authors.initials: J
authors.lastname: Lu
authors.forename: Caiyu
authors.initials: C
authors.lastname: Xiang
authors.forename: Hongping
authors.initials: H
authors.lastname: Ju
authors.forename: Jiaan
authors.initials: J
authors.lastname: Cheng
authors.forename: Yonggen
authors.initials: Y
authors.lastname: Lou
mesh_terms: D000818:Animals; D002736:Chloroplasts / Q000378:metabolism; D003517:Cyclopentanes / Q000032:analysis; D060467:Disease Resistance; D005260:Female; D018506:Gene Expression Regulation, Plant; D006430:Hemiptera / Q000502:physiology; D060434:Herbivory; D007915:Lepidoptera / Q000502:physiology; D008084:Lipoxygenase / Q000235:genetics* / Q000378:metabolism; D012275:Oryza / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000276:immunology; D054883:Oxylipins / Q000032:analysis / Q000378:metabolism; D010937:Plant Growth Regulators / Q000032:analysis; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000166:cytology / Q000201:enzymology / Q000235:genetics / Q000276:immunology; D030821:Plants, Genetically Modified; D059386:Reverse Genetics; D020156:Salicylic Acid / Q000032:analysis
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; C011006:jasmonic acid; C117433:13-lipoxygenase; D008084:Lipoxygenase; D020156:Salicylic Acid