title: Phospholipases C and D modulate proline accumulation in Thellungiella halophila/salsuginea differently according to the severity of salt or hyperosmotic stress.
abstract: Proline accumulation is one of the most common responses of plants to environmental constraints. Thellungiella halophila/salsuginea, a model halophyte, accumulates high levels of proline in response to abiotic stress and in the absence of stress. Recently, lipid signaling pathways have been shown to be involved in the regulation of proline metabolism in Arabidopsis thaliana. Here we investigated the relationship between lipid signaling enzymes and the level of proline in T. salsuginea. Inhibition of phospholipase C (PLC) enzymes by the specific inhibitor U73122 demonstrated that proline accumulation is negatively controlled by PLCs in the absence of stress and under moderate salt stress (200 mM NaCl). The use of 1-butanol to divert some of the phospholipase D (PLD)-derived phosphatidic acid by transphosphatidylation revealed that PLDs exert a positive control on proline accumulation under severe stress (400 mM NaCl or 400 mM mannitol) but have no effect on its accumulation in non-stress conditions. This experimental evidence shows that positive and negative lipid regulatory components are involved in the fine regulation of proline metabolism. These signaling pathways in T. salsuginea are regulated in the opposite sense to those previously described in A. thaliana, revealing that common signaling components affect the physiology of closely related glycophyte and salt-tolerant plants differently.
authors: UPMC Université Paris 06, UR5 EAC7180 CNRS, Physiologie Cellulaire et Moléculaire des Plantes, Paris, France.
authors: Mohamed Ali
authors: MA
authors: Ghars
authors: Luc
authors: L
authors: Richard
authors: Delphine
authors: D
authors: Lefebvre-De Vos
authors: Anne-Sophie
authors: AS
authors: Leprince
authors: Elodie
authors: E
authors: Parre
authors: Marianne
authors: M
authors: Bordenave
authors: Chedly
authors: C
authors: Abdelly
authors: Arnould
authors: A
authors: Savouré
mesh_terms: D020001:1-Butanol / Q000494:pharmacology; D019607:Brassicaceae / Q000187:drug effects / Q000201:enzymology*; D004963:Estrenes / Q000494:pharmacology; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects; D008353:Mannitol / Q000494:pharmacology; D008954:Models, Biological; D009995:Osmosis / Q000187:drug effects; D010739:Phospholipase D / Q000378:metabolism*; D011392:Proline / Q000378:metabolism*; D011760:Pyrrolidinones / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological / Q000187:drug effects*; D010738:Type C Phospholipases / Q000378:metabolism*
chemical_list: D004963:Estrenes; D011760:Pyrrolidinones; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D008353:Mannitol; D012965:Sodium Chloride; D020001:1-Butanol; D011392:Proline; D010738:Type C Phospholipases; D010739:Phospholipase D