title: Multiple PLDs required for high salinity and water deficit tolerance in plants.
abstract: High salinity and drought have received much attention because they severely affect crop production worldwide. Analysis and comprehension of the plant's response to excessive salt and dehydration will aid in the development of stress-tolerant crop varieties. Signal transduction lies at the basis of the response to these stresses, and numerous signaling pathways have been implicated. Here, we provide further evidence for the involvement of phospholipase D (PLD) in the plant's response to high salinity and dehydration. A tomato (Lycopersicon esculentum) alpha-class PLD, LePLDalpha1, is transcriptionally up-regulated and activated in cell suspension cultures treated with salt. Gene silencing revealed that this PLD is indeed involved in the salt-induced phosphatidic acid production, but not exclusively. Genetically modified tomato plants with reduced LePLDalpha1 protein levels did not reveal altered salt tolerance. In Arabidopsis (Arabidopsis thaliana), both AtPLDalpha1 and AtPLDdelta were found to be activated in response to salt stress. Moreover, pldalpha1 and plddelta single and double knock-out mutants exhibited enhanced sensitivity to high salinity stress in a plate assay. Furthermore, we show that both PLDs are activated upon dehydration and the knock-out mutants are hypersensitive to hyperosmotic stress, displaying strongly reduced growth.
authors.affiliation: Section of Plant Physiology, Swammerdam Institute for Life Sciences (SILS), Universiteit van Amsterdam, Amsterdam, The Netherlands.
authors.forename: Bastiaan O R
authors.initials: BO
authors.lastname: Bargmann
authors.forename: Ana M
authors.initials: AM
authors.lastname: Laxalt
authors.forename: Bas
authors.initials: B
authors.lastname: ter Riet
authors.forename: Bas
authors.initials: B
authors.lastname: van Schooten
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Merquiol
authors.forename: Christa
authors.initials: C
authors.lastname: Testerink
authors.forename: Michel A
authors.initials: MA
authors.lastname: Haring
authors.forename: Dorothea
authors.initials: D
authors.lastname: Bartels
authors.forename: Teun
authors.initials: T
authors.lastname: Munnik
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D002478:Cells, Cultured; D003681:Dehydration; D055786:Gene Knockout Techniques; D020868:Gene Silencing; D017343:Genes, Plant; D018551:Solanum lycopersicum / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D010739:Phospholipase D / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D054712:Salinity; D055051:Salt-Tolerant Plants / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D012965:Sodium Chloride / Q000494:pharmacology; D014867:Water / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D014867:Water; D012965:Sodium Chloride; D010739:Phospholipase D