title: The role of lipid metabolism in the acquisition of desiccation tolerance in Craterostigma plantagineum: a comparative approach.
abstract: Dehydration leads to different physiological and biochemical responses in plants. We analysed the lipid composition and the expression of genes involved in lipid biosynthesis in the desiccation-tolerant plant Craterostigma plantagineum. A comparative approach was carried out with Lindernia brevidens (desiccation tolerant) and two desiccation-sensitive species, Lindernia subracemosa and Arabidopsis thaliana. In C. plantagineum the total lipid content remained constant while the lipid composition underwent major changes during desiccation. The most prominent change was the removal of monogalactosyldiacylglycerol (MGDG) from the thylakoids. Analysis of molecular species composition revealed that around 50% of 36:x (number of carbons in the acyl chains: number of double bonds) MGDG was hydrolysed and diacylglycerol (DAG) used for phospholipid synthesis, while another MGDG fraction was converted into digalactosyldiacylglycerol via the DGD1/DGD2 pathway and subsequently into oligogalactolipids by SFR2. 36:x-DAG was also employed for the synthesis of triacylglycerol. Phosphatidic acid (PA) increased in C. plantagineum, L. brevidens, and L. subracemosa, in agreement with a role of PA as an intermediate of lipid turnover and of phospholipase D in signalling during desiccation. 34:x-DAG, presumably derived from de novo assembly, was converted into phosphatidylinositol (PI) in C. plantagineum and L. brevidens, but not in desiccation-sensitive plants, suggesting that PI is involved in acquisition of desiccation tolerance. The accumulation of oligogalactolipids and PI in the chloroplast and extraplastidial membranes, respectively, increases the concentration of hydroxyl groups and enhances the ratio of bilayer- to non-bilayer-forming lipids, thus contributing to protein and membrane stabilization.
authors.affiliation: Botánica and ICBIBE, Fac. C. Biológicas, Universitat de València, C/Dr. Moliner 50, Burjassot, Valencia 46100, Spain; Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Kirschallee 1, Bonn D-53115, Germany.
authors.forename: Francisco
authors.initials: F
authors.lastname: Gasulla
authors.forename: Katharina
authors.initials: K
authors.lastname: Vom Dorp
authors.forename: Isabel
authors.initials: I
authors.lastname: Dombrink
authors.forename: Ulrich
authors.initials: U
authors.lastname: Zähringer
authors.forename: Nicolas
authors.initials: N
authors.lastname: Gisch
authors.forename: Peter
authors.initials: P
authors.lastname: Dörmann
authors.forename: Dorothea
authors.initials: D
authors.lastname: Bartels
mesh_terms: D017360:Arabidopsis / Q000378:metabolism / Q000502:physiology; D032181:Craterostigma / Q000378:metabolism* / Q000502:physiology; D003890:Desiccation; D019669:Embryophyta / Q000378:metabolism / Q000502:physiology; D038983:Galactolipids / Q000378:metabolism; D006868:Hydrolysis; D050356:Lipid Metabolism; D013312:Stress, Physiological; D053719:Tandem Mass Spectrometry
chemical_list: D038983:Galactolipids; C007388:digalactosyldiacylglycerol; C009909:monogalactosyldiacylglycerol
keywords: Arabidopsis thaliana; Craterostigma plantagineum; Lindernia brevidens; Lindernia subracemosa; drought; galactolipids; phosphatidylinositol; resurrection plant