title: Positive effects of salicylic acid pretreatment on the composition of flax plastidial membrane lipids under cadmium stress.
abstract: Interest in use of flax (Linum usitatissimum L.) as cadmium (Cd)-accumulating plant for phytoextraction of contaminated soils opened up a new and promising avenue toward improving tolerance of its varieties and cultivars to Cd stress. The aim of this study is to get insights into the mechanisms of Cd detoxification in cell membranes, by exploring the effects of salicylic acid (SA)-induced priming on fatty acids and lipid composition of flax plantlets, grown for 10 days with 50 and 100 μM Cd. At leaf level, levels of monogalactosyldiacylglycerol (MGDG), phosphatidylcholine (PC), phosphatidylglycerol (PG), and neutral lipids (NL) have shifted significantly in flax plantlets exposed to toxic CdCl2 concentrations, as compared to that of the control. At 100 μM Cd, the linoleic acid (C18:2) decreases mainly in digalactosyldiacylglycerol (DGDG) and all phospholipid species, while linolenic acid (C18:3) declines mostly in MGDG and NL. Conversely, at the highest concentration of the metal, SA significantly enhances the levels of MGDG, PG and phosphatidic acid (PA), and polyunsaturated fatty acids mainly C18:2 and C18:3. Furthermore, SA pretreatment seems to reduce the Cd-induced alterations in both plastidial and extraplastidial lipid classes, but preferentially preserves the plastidial lipids by acquiring higher levels of polyunsaturated fatty acids. These results suggest that flax plantlets pretreated with SA exhibits more stability of their membranes under Cd-stress conditions.
authors.affiliation: Département de Biologie, Unité de Recherche de Physiologie et Biochimie de la tolérance des plantes aux contraintes abiotiques, Faculté des Sciences de Tunis, Campus Universitaire, 1060, Tunis, Tunisia, belkadhiaicha@ymail.com.
authors.forename: Aïcha
authors.initials: A
authors.lastname: Belkadhi
authors.forename: Antonio
authors.initials: A
authors.lastname: De Haro
authors.forename: Sara
authors.initials: S
authors.lastname: Obregon
authors.forename: Wided
authors.initials: W
authors.lastname: Chaïbi
authors.forename: Wahbi
authors.initials: W
authors.lastname: Djebali
mesh_terms: D065966:Absorption, Physicochemical; D001673:Biodegradation, Environmental; D019256:Cadmium Chloride / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D005227:Fatty Acids / Q000032:analysis; D019597:Flax / Q000737:chemistry*; D038983:Galactolipids / Q000032:analysis; D008563:Membrane Lipids / Q000032:analysis*; D010743:Phospholipids / Q000032:analysis; D018515:Plant Leaves / Q000737:chemistry* / Q000187:drug effects; D018087:Plastids / Q000737:chemistry* / Q000187:drug effects; D020156:Salicylic Acid / Q000494:pharmacology*; D012989:Soil Pollutants / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D005227:Fatty Acids; D038983:Galactolipids; D008563:Membrane Lipids; D010743:Phospholipids; D012989:Soil Pollutants; C007388:digalactosyldiacylglycerol; C009909:monogalactosyldiacylglycerol; D019256:Cadmium Chloride; D020156:Salicylic Acid