title: Modulation of plant defense responses to herbivores by simultaneous recognition of different herbivore-associated elicitors in rice.
abstract: Induced plant defense responses against insect herbivores are triggered by wounding and/or perception of herbivore elicitors from their oral secretions (OS) and/or saliva. In this study, we analyzed OS isolated from two rice chewing herbivores, Mythimna loreyi and Parnara guttata. Both types of crude OS had substantial elicitor activity in rice cell system that allowed rapid detection of early and late defense responses, i.e. accumulation of reactive oxygen species (ROS) and defense secondary metabolites, respectively. While the OS from M. loreyi contained large amounts of previously reported insect elicitors, fatty acid-amino acid conjugates (FACs), the elicitor-active P. guttata's OS contained no detectable FACs. Subsequently, elicitor activity associated with the high molecular mass fraction in OS of both herbivores was identified, and shown to promote ROS and metabolite accumulations in rice cells. Notably, the application of N-linolenoyl-Gln (FAC) alone had only negligible elicitor activity in rice cells; however, the activity of isolated elicitor fraction was substantially promoted by this FAC. Our results reveal that plants integrate various independent signals associated with their insect attackers to modulate their defense responses and reach maximal fitness in nature.
authors: Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama 710-0046, Japan.
authors: Tomonori
authors: T
authors: Shinya
authors: Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama 710-0046, Japan.
authors: Yuko
authors: Y
authors: Hojo
authors: Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki, Kanagawa 214-8571, Japan.
authors: Yoshitake
authors: Y
authors: Desaki
authors: The New Zealand Institute for Plant &Food Research, Palmerston North 4442, New Zealand.
authors: John T
authors: JT
authors: Christeller
authors: Biotechnology Research Center, The University of Tokyo, Tokyo 113-8657, Japan.
authors: Kazunori
authors: K
authors: Okada
authors: Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki, Kanagawa 214-8571, Japan.
authors: Naoto
authors: N
authors: Shibuya
authors: Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama 710-0046, Japan.
authors: Ivan
authors: I
authors: Galis
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D005227:Fatty Acids / Q000737:chemistry; D060434:Herbivory / Q000502:physiology; D007915:Lepidoptera / Q000187:drug effects / Q000472:pathogenicity / Q000502:physiology; D012275:Oryza / Q000276:immunology* / Q000378:metabolism / Q000469:parasitology; D057865:Plant Immunity; D018515:Plant Leaves / Q000276:immunology* / Q000378:metabolism / Q000469:parasitology; D017382:Reactive Oxygen Species / Q000276:immunology / Q000378:metabolism; D012463:Saliva / Q000737:chemistry; D064210:Secondary Metabolism / Q000276:immunology*
chemical_list: D000596:Amino Acids; D005227:Fatty Acids; D017382:Reactive Oxygen Species