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Silencing OsHI‐LOX makes rice more susceptible to chewing herbivores, but enhances resistance to a phloem feeder
Author(s) -
Zhou Guoxin,
Qi Jinfeng,
Ren Nan,
Cheng Jiaan,
Erb Matthias,
Mao Bizeng,
Lou Yonggen
Publication year - 2009
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2009.03988.x
Subject(s) - jasmonic acid , phloem , salicylic acid , biology , chilo suppressalis , herbivore , brown planthopper , plant defense against herbivory , insect , botany , cnaphalocrocis medinalis , genetically modified crops , planthopper , rice plant , larva , biochemistry , horticulture , gene , transgene , lepidoptera genitalia , hemiptera
Summary The jasmonic acid (JA) pathway plays a central role in plant defense responses against insects. Some phloem‐feeding insects also induce the salicylic acid (SA) pathway, thereby suppressing the plant’s JA response. These phenomena have been well studied in dicotyledonous plants, but little is known about them in monocotyledons. We cloned a chloroplast‐localized type 2 13‐lipoxygenase gene of rice, OsHI‐LOX , whose transcripts were up‐regulated in response to feeding by the rice striped stem borer (SSB) Chilo suppressalis and the rice brown planthopper (BPH) Niaparvata lugens , as well as by mechanical wounding and treatment with JA. Antisense expression of OsHI‐LOX (as‐ lox ) reduced SSB‐ or BPH‐induced JA and trypsin protease inhibitor (TrypPI) levels, improved the larval performance of SBB as well as that of the rice leaf folder (LF) Cnaphalocrocis medinalis , and increased the damage caused by SSB and LF larvae. In contrast, BPH, a phloem‐feeding herbivore, showed a preference for settling and ovipositing on WT plants, on which they consumed more and survived better than on as‐ lox plants. The enhanced resistance of as‐ lox plants to BPH infestation correlated with higher levels of BPH‐induced H 2 O 2 and SA, as well as with increased hypersensitive response‐like cell death. These results imply that OsHI‐LOX is involved in herbivore‐induced JA biosynthesis, and plays contrasting roles in controlling rice resistance to chewing and phloem‐feeding herbivores. The observation that suppression of JA activity results in increased resistance to an insect indicates that revision of the generalized plant defense models in monocotyledons is required, and may help develop novel strategies to protect rice against insect pests.