The COP9 signalosome controls jasmonic acid synthesis and plant responses to herbivory and pathogens.
The COP9 signalosome (CSN) is a multi-protein complex that regulates the activities of cullin-RING E3 ubiquitin ligases (CRLs). CRLs ubiquitinate proteins in order to target them for proteasomal degradation. The CSN is required for proper plant development. Here we show that the CSN also has a profound effect on plant defense responses. Silencing of genes for CSN subunits in tomato plants resulted in a mild morphological phenotype and reduced expression of wound-responsive genes in response to mechanical wounding, attack by Manduca sexta larvae, and Prosystemin over-expression. In contrast, expression of pathogenesis-related genes was increased in a stimulus-independent manner in these plants. The reduced wound response in CSN-silenced plants corresponded with reduced synthesis of jasmonic acid (JA), but levels of salicylic acid (SA) were unaltered. As a consequence, these plants exhibited reduced resistance against herbivorous M. sexta larvae and the necrotrophic fungal pathogen Botrytis cinerea. In contrast, susceptibility to tobacco mosaic virus (TMV) was not altered in CSN-silenced plants. These data demonstrate that the CSN orchestrates not only plant development but also JA-dependent plant defense responses.
Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA.
Sarah R
SR
Hind
Sarah E
SE
Pulliam
Paola
P
Veronese
Deepak
D
Shantharaj
Azka
A
Nazir
Nekaiya S
NS
Jacobs
Johannes W
JW
Stratmann
D000818:Animals; D020171:Botrytis / Q000276:immunology / Q000472:pathogenicity; D000075686:COP9 Signalosome Complex; D003517:Cyclopentanes / Q000032:analysis / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000276:immunology; D020868:Gene Silencing; D018551:Solanum lycopersicum / Q000235:genetics / Q000382:microbiology / Q000469:parasitology / Q000502:physiology*; D018402:Manduca / Q000276:immunology / Q000472:pathogenicity; D046912:Multiprotein Complexes / Q000235:genetics / Q000502:physiology*; D054883:Oxylipins / Q000032:analysis / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000235:genetics / Q000502:physiology*; D010641:Phenotype; D010935:Plant Diseases; D057865:Plant Immunity / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics / Q000502:physiology*; D020156:Salicylic Acid / Q000032:analysis / Q000378:metabolism; D014027:Tobacco Mosaic Virus / Q000276:immunology / Q000472:pathogenicity; D014947:Wounds and Injuries
D003517:Cyclopentanes; D046912:Multiprotein Complexes; D054883:Oxylipins; D010940:Plant Proteins; C011006:jasmonic acid; D010447:Peptide Hydrolases; D000075686:COP9 Signalosome Complex; D020156:Salicylic Acid