title: Jasmonic Acid and Ethylene Signaling Pathways Regulate Glucosinolate Levels in Plants During Rhizobacteria-Induced Systemic Resistance Against a Leaf-Chewing Herbivore.
abstract: Beneficial soil microbes can promote plant growth and induce systemic resistance (ISR) in aboveground tissues against pathogens and herbivorous insects. Despite the increasing interest in microbial-ISR against herbivores, the underlying molecular and chemical mechanisms of this phenomenon remain elusive. Using Arabidopsis thaliana and the rhizobacterium Pseudomonas simiae WCS417r (formerly known as P. fluorescens WCS417r), we here evaluate the role of the JA-regulated MYC2-branch and the JA/ET-regulated ORA59-branch in modulating rhizobacteria-ISR to Mamestra brassicae by combining gene transcriptional, phytochemical, and herbivore performance assays. Our data show a consistent negative effect of rhizobacteria-mediated ISR on the performance of M. brassicae. Functional JA- and ET-signaling pathways are required for this effect, as shown by investigating the knock-out mutants dde2-2 and ein2-1. Additionally, whereas herbivory mainly induces the MYC2-branch, rhizobacterial colonization alone or in combination with herbivore infestation induces the ORA59-branch of the JA signaling pathway. Rhizobacterial colonization enhances the synthesis of camalexin and aliphatic glucosinolates (GLS) compared to the control, while it suppresses the herbivore-induced levels of indole GLS. These changes are associated with modulation of the JA-/ET-signaling pathways. Our data show that the colonization of plant roots by rhizobacteria modulates plant-insect interactions by prioritizing the JA/ET-regulated ORA59-branch over the JA-regulated MYC2-branch. This study elucidates how microbial plant symbionts can modulate the plant immune system to mount an effective defense response against herbivorous plant attackers.
authors.affiliation: Laboratory of Entomology, Wageningen University, P.O. Box 16, 6700 AA, Wageningen, The Netherlands. npangesti001@gmail.com.
authors.forename: Nurmi
authors.initials: N
authors.lastname: Pangesti
authors.affiliation: Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745, Jena, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Reichelt
authors.affiliation: Laboratory of Phytopathology, Wageningen University, P.O. Box 16, 6700 AA, Wageningen, The Netherlands.|HAS University of Applied Sciences, 5911 KJ, Venlo, The Netherlands.
authors.forename: Judith E
authors.initials: JE
authors.lastname: van de Mortel
authors.affiliation: Laboratory of Entomology, Wageningen University, P.O. Box 16, 6700 AA, Wageningen, The Netherlands.
authors.forename: Eleni
authors.initials: E
authors.lastname: Kapsomenou
authors.affiliation: Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745, Jena, Germany.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Gershenzon
authors.affiliation: Laboratory of Entomology, Wageningen University, P.O. Box 16, 6700 AA, Wageningen, The Netherlands.
authors.forename: Joop J A
authors.initials: JJ
authors.lastname: van Loon
authors.affiliation: Laboratory of Entomology, Wageningen University, P.O. Box 16, 6700 AA, Wageningen, The Netherlands.
authors.forename: Marcel
authors.initials: M
authors.lastname: Dicke
authors.affiliation: Laboratory of Entomology, Wageningen University, P.O. Box 16, 6700 AA, Wageningen, The Netherlands.|Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), PO Box 50, 6700 AB, Wageningen, The Netherlands.
authors.forename: Ana
authors.initials: A
authors.lastname: Pineda
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000235:genetics / Q000382:microbiology / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism*; D005030:Ethylenes / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D005961:Glucosinolates / Q000378:metabolism*; D060434:Herbivory; D007211:Indoles / Q000378:metabolism; D007915:Lepidoptera / Q000502:physiology*; D054883:Oxylipins / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism*; D018517:Plant Roots / Q000382:microbiology / Q000502:physiology; D011549:Pseudomonas / Q000502:physiology*; D012231:Rhizobium / Q000502:physiology; D015398:Signal Transduction; D013559:Symbiosis; D013844:Thiazoles / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D000094162:Phytoalexins
chemical_list: D029681:Arabidopsis Proteins; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D003517:Cyclopentanes; D005030:Ethylenes; D005961:Glucosinolates; D007211:Indoles; D054883:Oxylipins; D010937:Plant Growth Regulators; D013844:Thiazoles; D014157:Transcription Factors; C473611:MYC2 protein, Arabidopsis; C531343:ORA59 protein, Arabidopsis; C102405:camalexin; D000094162:Phytoalexins; C011006:jasmonic acid
keywords: Camalexin; Glucosinolates; Induced systemic resistance; Plant growth-promoting rhizobacteria; Signaling pathways