title: Pathogen-triggered ethylene signaling mediates systemic-induced susceptibility to herbivory in Arabidopsis.
abstract: Multicellular eukaryotic organisms are attacked by numerous parasites from diverse phyla, often simultaneously or sequentially. An outstanding question in these interactions is how hosts integrate signals induced by the attack of different parasites. We used a model system comprised of the plant host Arabidopsis thaliana, the hemibiotrophic bacterial phytopathogen Pseudomonas syringae, and herbivorous larvae of the moth Trichoplusia ni (cabbage looper) to characterize mechanisms involved in systemic-induced susceptibility (SIS) to T. ni herbivory caused by prior infection by virulent P. syringae. We uncovered a complex multilayered induction mechanism for SIS to herbivory. In this mechanism, antiherbivore defenses that depend on signaling via (1) the jasmonic acid-isoleucine conjugate (JA-Ile) and (2) other octadecanoids are suppressed by microbe-associated molecular pattern-triggered salicylic acid (SA) signaling and infection-triggered ethylene signaling, respectively. SIS to herbivory is, in turn, counteracted by a combination of the bacterial JA-Ile mimic coronatine and type III virulence-associated effectors. Our results show that SIS to herbivory involves more than antagonistic signaling between SA and JA-Ile and provide insight into the unexpectedly complex mechanisms behind a seemingly simple trade-off in plant defense against multiple enemies.
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138.
authors.forename: Simon C
authors.initials: SC
authors.lastname: Groen
authors.forename: Noah K
authors.initials: NK
authors.lastname: Whiteman
authors.forename: Adam K
authors.initials: AK
authors.lastname: Bahrami
authors.forename: Amity M
authors.initials: AM
authors.lastname: Wilczek
authors.forename: Jianping
authors.initials: J
authors.lastname: Cui
authors.forename: Jacob A
authors.initials: JA
authors.lastname: Russell
authors.forename: Angelica
authors.initials: A
authors.lastname: Cibrian-Jaramillo
authors.forename: Ian A
authors.initials: IA
authors.lastname: Butler
authors.forename: Jignasha D
authors.initials: JD
authors.lastname: Rana
authors.forename: Guo-Hua
authors.initials: GH
authors.lastname: Huang
authors.forename: Jenifer
authors.initials: J
authors.lastname: Bush
authors.forename: Frederick M
authors.initials: FM
authors.lastname: Ausubel
authors.forename: Naomi E
authors.initials: NE
authors.lastname: Pierce
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases / Q000235:genetics / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D060434:Herbivory; D007532:Isoleucine / Q000378:metabolism; D009036:Moths; D009154:Mutation; D054883:Oxylipins / Q000378:metabolism; D018515:Plant Leaves; D044224:Pseudomonas syringae / Q000472:pathogenicity; D020156:Salicylic Acid / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D005030:Ethylenes; D054883:Oxylipins; D007532:Isoleucine; C011006:jasmonic acid; C036216:ethylene; D002265:Carboxylic Ester Hydrolases; C400766:PAD4 protein, Arabidopsis; D020156:Salicylic Acid