title: Sphingolipid long chain base phosphates can regulate apoptotic-like programmed cell death in plants.
abstract: Sphingolipids are ubiquitous components of eukaryotic cells and sphingolipid metabolites, such as the long chain base phosphate (LCB-P), sphingosine 1 phosphate (S1P) and ceramide (Cer) are important regulators of apoptosis in animal cells. This study evaluated the role of LCB-Ps in regulating apoptotic-like programmed cell death (AL-PCD) in plant cells using commercially available S1P as a tool. Arabidopsis cell cultures were exposed to a diverse array of cell death-inducing treatments (including Cer) in the presence of S1P. Rates of AL-PCD and cell survival were recorded using vital stains and morphological markers of AL-PCD. Internal LCB-P levels were altered in suspension cultured cells using inhibitors of sphingosine kinase and changes in rates of death in response to heat stress were evaluated. S1P reduced AL-PCD and promoted cell survival in cells subjected to a range of stresses. Treatments with inhibitors of sphingosine kinase lowered the temperature which induced maximal AL-PCD in cell cultures. The data supports the existence of a sphingolipid rheostat involved in controlling cell fate in Arabidopsis cells and that sphingolipid regulation of cell death may be a shared feature of both animal apoptosis and plant AL-PCD.
authors.affiliation: School of Biology and Environmental Science, University College Dublin, Dublin 4, Ireland.
authors.forename: Keith P
authors.initials: KP
authors.lastname: Alden
authors.forename: Sandrine
authors.initials: S
authors.lastname: Dhondt-Cordelier
authors.forename: Kerrie L
authors.initials: KL
authors.lastname: McDonald
authors.forename: Theresa J
authors.initials: TJ
authors.lastname: Reape
authors.forename: Carl K-Y
authors.initials: CK
authors.lastname: Ng
authors.forename: Paul F
authors.initials: PF
authors.lastname: McCabe
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Leaver
mesh_terms: D017209:Apoptosis; D017360:Arabidopsis / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D002518:Ceramides / Q000494:pharmacology / Q000502:physiology*; D018869:Heat-Shock Response; D008246:Lysophospholipids / Q000494:pharmacology / Q000502:physiology*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000037:antagonists & inhibitors / Q000378:metabolism; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000502:physiology; D000099157:Sphingosine Kinase
chemical_list: D002518:Ceramides; D008246:Lysophospholipids; D017853:Phosphotransferases (Alcohol Group Acceptor); D013110:Sphingosine; D000099157:Sphingosine Kinase; C060506:sphingosine 1-phosphate; C061800:N,N-dimethylsphingosine