title: NaJAZh regulates a subset of defense responses against herbivores and spontaneous leaf necrosis in Nicotiana attenuata plants.
abstract: The JASMONATE ZIM DOMAIN (JAZ) proteins function as negative regulators of jasmonic acid signaling in plants. We cloned 12 JAZ genes from native tobacco (Nicotiana attenuata), including nine novel JAZs in tobacco, and examined their expression in plants that had leaves elicited by wounding or simulated herbivory. Most JAZ genes showed strong expression in the elicited leaves, but NaJAZg was mainly expressed in roots. Another novel herbivory-elicited gene, NaJAZh, was analyzed in detail. RNA interference suppression of this gene in inverted-repeat (ir)JAZh plants deregulated a specific branch of jasmonic acid-dependent direct and indirect defenses: irJAZh plants showed greater trypsin protease inhibitor activity, 17-hydroxygeranyllinalool diterpene glycosides accumulation, and emission of volatile organic compounds from leaves. Silencing of NaJAZh also revealed a novel cross talk in JAZ-regulated secondary metabolism, as irJAZh plants had significantly reduced nicotine levels. In addition, irJAZh spontaneously developed leaf necrosis during the transition to flowering. Because the lesions closely correlated with the elevated expression of programmed cell death genes and the accumulations of salicylic acid and hydrogen peroxide in the leaves, we propose a novel role of the NaJAZh protein as a repressor of necrosis and/or programmed cell death during plant development.
authors.affiliation: Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena D-07745, Germany.
authors.forename: Youngjoo
authors.initials: Y
authors.lastname: Oh
authors.forename: Ian T
authors.initials: IT
authors.lastname: Baldwin
authors.forename: Ivan
authors.initials: I
authors.lastname: Gális
mesh_terms: D016960:Agrobacterium tumefaciens / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D016923:Cell Death; D003001:Cloning, Molecular; D003517:Cyclopentanes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D060434:Herbivory; D006861:Hydrogen Peroxide / Q000378:metabolism; D018402:Manduca / Q000502:physiology; D008969:Molecular Sequence Data; D054883:Oxylipins / Q000378:metabolism; D010641:Phenotype; D010802:Phylogeny; D018515:Plant Leaves / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified / Q000235:genetics / Q000502:physiology; D034622:RNA Interference; D017382:Reactive Oxygen Species / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D020156:Salicylic Acid / Q000378:metabolism; D015398:Signal Transduction; D014026:Nicotiana / Q000235:genetics / Q000502:physiology*; D055549:Volatile Organic Compounds / Q000378:metabolism
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D012097:Repressor Proteins; D055549:Volatile Organic Compounds; C011006:jasmonic acid; D006861:Hydrogen Peroxide; D020156:Salicylic Acid