title: Contrasting effects of ethylene biosynthesis on induced plant resistance against a chewing and a piercing-sucking herbivore in rice.
abstract: Ethylene is a stress hormone with contrasting effects on herbivore resistance. However, it remains unknown whether these differences are plant- or herbivore-specific. We cloned a rice 1-aminocyclopropane-1-carboxylic acid (ACC) synthase gene, OsACS2, whose transcripts were rapidly up-regulated in response to mechanical wounding and infestation by two important pests: the striped stem borer (SSB) Chilo suppressalis and the brown planthopper (BPH) Nilaparvata lugens. Antisense expression of OsACS2 (as-acs) reduced elicited ethylene emission, SSB-elicited trypsin protease inhibitor (TrypPI) activity, SSB-induced volatile release, and SSB resistance. Exogenous application of ACC restored TrypPI activity and SSB resistance. In contrast to SSB, BPH infestation increased volatile emission in as-acs lines. Accordingly, BPH preferred to feed and oviposit on wild-type (WT) plants--an effect that could be attributed to two repellent volatiles, 2-heptanone and 2-heptanol, that were emitted in higher amounts by as-acs plants. BPH honeydew excretion was reduced and natural enemy attraction was enhanced in as-acs lines, resulting in higher overall resistance to BPH. These results demonstrate that ethylene signaling has contrasting, herbivore-specific effects on rice defense responses and resistance against a chewing and a piercing-sucking insect, and may mediate resistance trade-offs between herbivores of different feeding guilds in rice.
authors: State Key Laboratory of Rice Biology, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China.
authors: Jing
authors: J
authors: Lu
authors: State Key Laboratory of Rice Biology, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China.
authors: Jiancai
authors: J
authors: Li
authors: State Key Laboratory of Rice Biology, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China.
authors: Hongping
authors: H
authors: Ju
authors: State Key Laboratory of Rice Biology, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China.
authors: Xiaoli
authors: X
authors: Liu
authors: Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland.
authors: Matthias
authors: M
authors: Erb
authors: State Key Laboratory of Rice Biology, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China.
authors: Xia
authors: X
authors: Wang
authors: State Key Laboratory of Rice Biology, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China. Electronic address: yglou@zju.edu.cn.
authors: Yonggen
authors: Y
authors: Lou
mesh_terms: D000818:Animals; D005030:Ethylenes / Q000096:biosynthesis*; D018506:Gene Expression Regulation, Plant; D006430:Hemiptera / Q000502:physiology*; D060434:Herbivory; D008190:Lyases / Q000235:genetics / Q000378:metabolism*; D012275:Oryza / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified
chemical_list: D005030:Ethylenes; D010940:Plant Proteins; C036216:ethylene; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase
keywords: OsACS2; direct defense; ethylene; herbivore resistance.; indirect defense; rice