ib Blackwell Publishing

Transcription

1 Plant Lipids Biology, Utilisation and Manipulation Edited by DENIS J. MURPHY Biotechnology Unit School of Applied Sciences University of Glamorgan Cardiff, UK ib Blackwell Publishing CRC Press

2 Contents Contributors Preface xiii xv 1 The study and utilisation of plant lipids: from margarine to lipid rafts 1 DENIS J. MURPHY 1.1 Introduction Early studies of plant lipids The chemistry era - and the definition of the term 'lipid' The biochemistry era The molecular genetics revolution New frontiers - cell biology and the 'omics Conclusions and future prospects 22 2 Fatty acid biosynthesis 27 JOHN L. HARWOOD 2.1 Introduction Carbon supply for fatty acid formation Acetyl-CoA carboxylase Structure of ACCase Properties of different isoforms of ACCase Herbicides acting on ACCase Genes coding for ACCase Regulation of ACCase Fatty acid synthase Acyl carrier protein Condensing enzymes The other component enzymes of FAS Termination of FAS Mitochondrial FAS Regulation of fatty acid formation Biotechnological aspects 56

3 vi CONTENTS 3 Fatty acid manipulation 67 DAVID F. HILDEBRAND, KESHUN YU, CHARLES MCCRACKEN and SURYADEVARA S. RAO 3.1 Introduction The soluble A9 desaturases Engineering chain length specificity of soluble A9 desaturases Stearoyl-CoA desaturases Front-end desaturases A12 Desaturase-like enzymes and their use in the modification of fatty acid residues Structures and functions Substrates and products Gene isolation, characterization and testing Rational gene design Segregation of novel fatty acids from membrane lipids Compartmentation of storage and membrane lipid synthesis Selective accumulation of novel fatty acids in oil bodies Medium-chain fatty acids Very-long-chain fatty acids Novel monoenoic fatty acids Novel fatty acids produced by diverged Fad2 enzymes Gene specific promoters for tissue specific novel fatty acid accumulation Structures and occurrences of hydroxy, conjugated and epoxy fatty acids in plant seed oils Hydroxy fatty acids Conjugated fatty acids Epoxy fatty acids 90 4 Non-food lipids 103 SEVIM Z. ERHAN and ATANU ADHVARYU 4.1 Introduction Structure and composition of lipids Simple lipids Triacylglycerols Industrial applications Industrial commodity seed oils Soybean oil Canolaoil 112

4 CONTENTS vii Sunflower oil Saffloweroil Linseed oil Tung oil New industrial oilseed crops Meadowfoam oil Lesquerella oil Cupheaoil Crambeoil Jojoba wax Use of tallow and yellow grease for industrial applications Structural modifications Interesterification Fractionation Solvent fractionation Column chromatography Thin-layer chromatography Hydrogenation Concluding remarks Membrane lipids 123 PETER DORMANN 5.1 Introduction Structures and localisation of glycerolipids Phosphatidic acid Galactolipids Sulfolipid Phosphatidylglycerol and diphosphatidylglycerol Phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and N-acyl-phosphatidylethanolamine Phosphatidylinositol Biosynthesis of membrane glycerolipids Biosynthesis of phosphatidic acid Synthesis of glycerolipids from diacylglycerol or CDP-diacylglycerol Biosynthesis of galactolipids Biosynthesis of sulfolipid Biosynthesis of PG and DPG Biosynthesis of PS, PC, PE and NAPE Biosynthesis of PI 139

5 viii CONTENTS 5.4 Membrane lipid turnover Hydrolysis of phospholipid head groups: phospholipases C and D ' Phospholipase C Phospholipase D Hydrolysis of acyl groups from membrane lipids Phospholipase A Phospholipase A Lysophospholipase Patatin-like acyl hydrolases with phospholipase and glycolipase activities DADl-like acylhydrolases SAGlOl-like acyl hydrolases and PDAT-like acyltransferases Glycolipases Fatty acyl turnover and acyl-coa synthetases Physiological roles of membrane lipids Growth at high and low temperatures Unsaturated fatty acids The role of unsaturated molecular species of PG in chilling sensitivity Increase of PC synthesis during cold treatment The role of thylakoid lipids in photosynthesis Growth during phosphate deprivation Summary and future perspectives Storage lipids 162 RANDALL J. WESELAKE 6.1 Introduction Pathways leading to triacylglycerols Properties and regulation of enzymes involved in triacylglycerol biosynthesis and associated phospholipid metabolism sm-glycerol-3-phosphate acyltransferase Lysophosphatidic acid acyltransferase Phosphatidic acid phosphatase Diacylglycerol acyltransferase Enzymes catalyzing acyl-coa-independent synthesis of triacylglycerol CDP-choline:-l,2-diacylglycerol cholinephosphotransferase Lysophosphatidylcholine acyltransferase 181

6 CONTENTS ix Phospholipases Soluble lysophosphatidic acid phosphatase and monoacylglycerol acyltransferase in developing peanut Complex metabolic processes can affect the fatty acid composition of triacylglycerol Structure, composition and biogenesis of lipid bodies Mobilization of storage lipids Degradation of triacylglycerols into fatty acids /S-Oxidation of fatty acids and conversion of lipid to carbohydrate /{-Oxidation during seed maturation Storage lipids in developing pollen grains Effect of environmental conditions and carbon source on triacylglycerol accumulation The role of lipid-protein particles and plasma membrane vesicles in membrane turnover Biosynthesis of liquid wax esters Do plants transport storage lipids? Conclusions and future directions Lipid-associated proteins 226 DENIS J. MURPHY 7.1 Introduction Plant lipid-associated proteins Oleosins Oleo-pollenins ('oleosin-like proteins') Caleosins Plastid lipid-associated proteins Minor lipid-associated proteins in plants Lipid-associated proteins in non-storage tissues in plants Phloem ' Roots and meristems Rubber Comparisons with non-plant systems Animals The PAT family of cytosolic lipid-body proteins Caveolins - the unexpected lipid-associated proteins Extracellular lipid-body proteins Microorganisms Fungi Prokaryotes Viruses Conclusions 258

7 CONTENTS The plant cuticle: formation and structure of epidermal surfaces 270 LJERKA KUNST, A.L. SAMUELS and REINHARD JETTER 8.1 Introduction Biosynthesis of cuticle components De novo fatty acid synthesis Cutin biosynthesis Synthesis of very-long-chain fatty acid wax precursors Synthesis of aliphatic cuticular wax components The acyl reduction pathway The decarbonylation pathway The /S-diketone pathway Cuticle biosynthesis in the context of the epidermal cell Saturated long-chain fatty acids are exported from the plastid to the ER for elongation VLCFA modification and delivery of wax constituents to the plasma membrane Export of wax components from the epidermal cell to the cuticle Cuticle composition and structure Formation and composition of epicuticular crystals Physical and chemical distinction between epicuticular film and intracuticular wax Crystalline arrangement of epi- and intracuticular wax molecules Conclusions 294 Inositol-containing lipids: roles in cellular signalling 303 BJ0RN K. DR0BAK 9.1 Introduction Phosphoinositides: synthesis, turnover and function Biosynthesis of phosphatidylinositol Phosphorylation of phosphatidylinositol and other phosphoinositides Phosphatidylinositol 3-kinases Phosphatidylinositol 4-kinases Phosphatidylinositol 5-kinases Phosphatidylinositol 3-monophosphate 5-kinases Phosphatidylinositol 4-monophosphate 5-kinases Phosphoinositide-protein interactions Profilin ADF/cofilin PARF and other FYVE-finger domain proteins Proteins containing PH-domains 319

8 CONTENTS xi Proteins containing PX-domains Proteins containing ENTH-, VHS-and FERM-domains Conclusions Oxylipins 329 SABINE ROSAHL AND IVO FEUSSNER 10.1 Introduction: synthesis of oxylipins LOX pathway The CYP74 family Jasmonic acid biosynthesis enzymes Oxylipins as signal molecules Jasmonic acid in wound signalling Systemic wound signalling The role of jasmonic acid in insect resistance Oxylipins and pathogen defence Jasmonic acid signal transduction mutants and their effects on the pathogen responses Cross-talk between salicylic acid and lipid signalling in pathogen defence responses LOX products - antimicrobial compounds and their impact on lipid peroxidation processes Conclusions and future prospects Prenyllipids and their derivatives: sterols, prenylquinones, carotenoids and terpenoids 355 PIERRE BENVENISTE 11.1 Introduction General considerations Prenylquinones Properties of prenylquinones Tocopherols and tocotrienols Plastoquinone Biosynthesis of prenylquinones Biosynthesis of tocopherol and plastoquinone Biosynthesis of tocotrienolquinones Carotenoids Biosynthesis of carotenoids Metabolic engineering of carotenoid biosynthesis Catabolism of carotenoids Sterols ,3(S)-oxidosqualene-cycloartenol cyclase (OSC) S-Adenosylmethionine-sterol-C-methyltransferases (SMTs) 368

9 Xll CONTENTS ,4-dimethyl sterol and 4a-methyl sterol 4-demethylation (SMOs) Cyclopropyl sterol isomerase (CPI) ' Obtusifoliol-14a-demethylase(OBT14DM) A sterol-a 14 -reductase(14red) A 8 -A 7 -sterol isomerase (8ISO) A 7 -sterol-c5(6)-desaturase(5des) A 57 -sterol A 7 -reductase (7RED) A 5 -sterol A 24 -reductase (isomerase) (DIM) Sterol-A 22 -desaturase Terpenoids, mono-, sesqui- and diterpenes Biosynthesis of Taxol (paclitaxel) Cyclisation of geranylgeranyl diphosphate Hydroxylations Acetylations, benzoylations phenylalanoylation Conclusions 379 List of Abbreviations 388 Index 394