title: Systematic analysis of rice (Oryza sativa) metabolic responses to herbivory.
abstract: Plants defend against attack from herbivores by direct and indirect defence mechanisms mediated by the accumulation of phytoalexins and release of volatile signals, respectively. While the defensive arsenals of some plants, such as tobacco and Arabidopsis are well known, most of rice's (Oryza sativa) defence metabolites and their effectiveness against herbivores remain uncharacterized. Here, we used a non-biassed metabolomics approach to identify many novel herbivory-regulated metabolic signatures in rice. Most were up-regulated by herbivore attack while only a few were suppressed. Two of the most prominent up-regulated signatures were characterized as phenolamides (PAs), p-coumaroylputrescine and feruloylputrescine. PAs accumulated in response to attack by both chewing insects, i.e. feeding of the lawn armyworm (Spodoptera mauritia) and the rice skipper (Parnara guttata) larvae, and the attack of the sucking insect, the brown planthopper (Nilaparvata lugens, BPH). In bioassays, BPH insects feeding on 15% sugar solution containing p-coumaroylputrescine or feruloylputrescine, at concentrations similar to those elicited by heavy BPH attack in rice, had a higher mortality compared to those feeding on sugar diet alone. Our results highlight PAs as a rapidly expanding new group of plant defence metabolites that are elicited by herbivore attack, and deter herbivores in rice and other plants.
authors.affiliation: Institute of Plant Science and Resources, Okayama University, Kurashiki, 710-0046, Japan.
authors.forename: Kabir Md
authors.initials: KM
authors.lastname: Alamgir
authors.affiliation: Institute of Plant Science and Resources, Okayama University, Kurashiki, 710-0046, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Hojo
authors.affiliation: Institute of Plant Science and Resources, Okayama University, Kurashiki, 710-0046, Japan.|The New Zealand Institute for Plant and Food Research Ltd, Private Bag 11600, Palmerston North, 4442, New Zealand.
authors.forename: John T
authors.initials: JT
authors.lastname: Christeller
authors.affiliation: Institute of Plant Science and Resources, Okayama University, Kurashiki, 710-0046, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Fukumoto
authors.affiliation: Institute of Plant Science and Resources, Okayama University, Kurashiki, 710-0046, Japan.
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Isshiki
authors.affiliation: Institute of Plant Science and Resources, Okayama University, Kurashiki, 710-0046, Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Shinya
authors.affiliation: Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena, D-07745, Germany.
authors.forename: Ian T
authors.initials: IT
authors.lastname: Baldwin
authors.affiliation: Institute of Plant Science and Resources, Okayama University, Kurashiki, 710-0046, Japan.
authors.forename: Ivan
authors.initials: I
authors.lastname: Galis
mesh_terms: D000577:Amides / Q000378:metabolism; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D006430:Hemiptera / Q000502:physiology; D060434:Herbivory / Q000502:physiology*; D055432:Metabolomics / Q000379:methods*; D012275:Oryza / Q000378:metabolism* / Q000469:parasitology*; D010935:Plant Diseases / Q000469:parasitology; D018515:Plant Leaves / Q000378:metabolism; D015203:Reproducibility of Results; D036226:Seedlings / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D049490:Systems Biology / Q000379:methods*
chemical_list: D000577:Amides
keywords: defence; diterpene phytoalexins (momilactones); feruloylputrescine (FP); herbivore damage; metabolomics; p-coumaroylputrescine (CoP); phenolamides (PAs); rice (Oryza sativa)