Jasmonate signaling pathway.
Jasmonates in plants are cyclic fatty acid-derived regulators structurally similar to prostaglandins in metazoans. These chemicals mediate many of plants' transcriptional responses to wounding and pathogenesis by acting as potent regulators for the expression of numerous frontline immune response genes, including those for defensins and antifungal proteins. Additionally, the pathway is critical for fertility. Ongoing genetic screens and protein-protein interaction assays are identifying components of the canonical jasmonate signaling pathway. A massive molecular machine, based on two multiprotein complexes, SCF(COI1) and the COP9 signalosome (CNS), plays a central role in jasmonate signaling. This machine functions in vivo as a ubiquitin ligase complex, probably targeting regulatory proteins, some of which are expected to be transcriptional repressors. Some defense-related mediators, notably salicylic acid, antagonize jasmonates in controlling the expression of many genes. In Arabidopsis, NONEXPRESSOR OF PR GENES (NPR1) mediates part of this interaction, with another layer of control provided further downstream by the mitogen-activated protein kinase (MAPK) homolog MPK4. Numerous other interpathway connections influence the jasmonate pathway. Insights from Arabidopsis have shown that an allele of the auxin signaling gene AXR1, for example, reduces the sensitivity of plants to jasmonate. APETALA2 (AP2)-domain transcription factors, such as ETHYLENE RESPONSE FACTOR 1 (ERF1), link the jasmonate pathway to the ethylene signaling pathway. As progress in characterizing several new mutants (some of which are hypersensitive to jasmonic acid) augments our understanding of jasmonate signaling, the Connections Map will be updated to include this new information.
Gene Expression Laboratory, Plant Molecular Biology, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland.
Robin
R
Liechti
Aurélie
A
Gfeller
Edward E
EE
Farmer
D017360:Arabidopsis / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000502:physiology; D000075686:COP9 Signalosome Complex; D003517:Cyclopentanes / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D008954:Models, Biological; D046912:Multiprotein Complexes / Q000502:physiology; D054883:Oxylipins; D010447:Peptide Hydrolases / Q000502:physiology; D010937:Plant Growth Regulators / Q000502:physiology*; D012459:Salicylates / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*
D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D046912:Multiprotein Complexes; D054883:Oxylipins; D010937:Plant Growth Regulators; D012459:Salicylates; C011006:jasmonic acid; D010447:Peptide Hydrolases; D000075686:COP9 Signalosome Complex