title: The squeeze cell hypothesis for the activation of jasmonate synthesis in response to wounding.
abstract: Jasmonates are lipid mediators that control defence gene expression in response to wounding and other environmental stresses. These small molecules can accumulate at distances up to several cm from sites of damage and this is likely to involve cell-to-cell jasmonate transport.Also, and independently of jasmonate synthesis, transport and perception, different long distance wound signals that stimulate distal jasmonate synthesis are propagated at apparent speeds of several cm min–1 to tissues distal to wounds in a mechanism that involves clade 3 GLUTAMATE RECEPTOR-LIKE (GLR) genes. A search for jasmonate synthesis enzymes that might decode these signals revealed LOX6, a lipoxygenase that is necessary for much of the rapid accumulation of jasmonic acid at sites distal to wounds. Intriguingly, the LOX6 promoter is expressed in a distinct niche of cells that are adjacent to mature xylem vessels,a location that would make these contact cells sensitive to the release of xylem water column tension upon wounding. We propose a model in which rapid axial changes in xylem hydrostatic pressure caused by wounding travel through the vasculature and lead to slower,radially dispersed pressure changes that act in a clade 3 GLR-dependent mechanism to promote distal jasmonate synthesis.
authors.affiliation: Department of Plant Molecular Biology, University of Lausanne, CH-1015, Lausanne, Switzerland.
authors.forename: Edward E
authors.initials: EE
authors.lastname: Farmer
authors.forename: Debora
authors.initials: D
authors.lastname: Gasperini
authors.forename: Iván F
authors.initials: IF
authors.lastname: Acosta
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism*; D006874:Hydrostatic Pressure; D008084:Lipoxygenase / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D054883:Oxylipins / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism*; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology; D058526:Plant Vascular Bundle / Q000235:genetics / Q000502:physiology; D031425:Plasmodesmata; D017981:Receptors, Neurotransmitter / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D015398:Signal Transduction; D013312:Stress, Physiological; D014947:Wounds and Injuries; D052584:Xylem / Q000235:genetics / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; D017981:Receptors, Neurotransmitter; C069474:glutamine receptor; C011006:jasmonic acid; D008084:Lipoxygenase
keywords: electrical signal,; glutamate receptor-like,; hydraulic signal,; jasmonate,; mechanosensor,; plasmodesmata,; squeeze cell hypothesis,; wounding