Plant Storage Lipids


Plant storage lipids, normally in the form of intracellular triacylglycerol‐rich droplets, are important sources of nutrition for people and livestock; besides, they supply a vast range of renewable industrial products from oleochemicals and bioplastics to paints and biofuels. Storage lipids are mainly found in plant propagules such as seeds and pollen grains, where they form an energy source for post‐germinative growth. The main commercial sources of plant storage lipids are oilseed crops such as soybean, rapeseed and maize or oil‐rich fruits such as olive or oil palm. Triacylglycerols also have several additional nonstorage functions in processes including host–pathogen interactions and abiotic stress responses. Improved knowledge of storage lipid metabolism is being used to create new oil crop varieties and to domesticate new species to supply the ever‐increasing demand for plant oils.

Key Concepts

  • How plants store energy reserves in the form of lipids.
  • What are the key storage lipids in plants.
  • How are plant storage lipids synthesised.
  • Where are store lipids made in plant cells.
  • What are the biotechnological uses of plant storage lipids.
  • How is storage lipid metabolism regulated and how can it be manipulated.

Keywords: fatty acids; oils; lipid droplets; diet; oilseeds; biofuels

Figure 1. Biosynthesis of storage lipids in plants: Import of carbon precursors. Sucrose is transported from photosynthetic tissues into developing seeds where it is converted in the cytosol of embryo and/or endosperm cells into precursors, such as glucose 6‐phosphate and phosphoenolpyruvate, for onward transport into plastids for production of fatty acids. Import into plastids occurs via specific carriers such as GPT, glucose 6‐phosphate transporter; TPT, triose phosphate transporter and PPT, phosphoenolpyruvate transporter. Fatty acid biosynthesis de novo: Acetyl‐CoA and malonyl‐CoA are the precursors for assembly of C8–C18 saturated fatty acyl‐ACPs on a plastidial multienzyme fatty acid synthetase complex. Plastids are also the site of the insertion of the first double bond by a soluble desaturase (SOL‐DES) to produce fatty acid monounsaturates. Both unsaturates and monounsaturates are exported via an acyl‐CoA transporter (ACT) from plastids to the endoplasmic reticulum for further processing. Fatty acid modification: Plastid‐derived acyl‐CoAs can be modified in the endoplasmic reticulum by a huge variety of enzymes to produce some of the hundreds of different fatty acids found in naturally occurring seed oils. However, as not all of these enzymes are present in any given plant species, nontransgenic oilseeds normally accumulate a relatively restricted range of fatty acids. Most fatty acid modification reactions occur via membrane‐bound phosphatidylcholine (PC) specific ER desaturases or desaturase‐like enzymes (ER‐DES) such as hydroxylases or epoxidases. Acyl‐CoAs are then assembled into complex lipids on the endoplasmic reticulum. Similar ER‐located pathways produce the various membrane lipids, storage lipids and also some signalling lipids although recent evidence suggests that these pathways are spatially separated in discrete ER domains. Storage oil bodies can accumulate virtually any type of fatty acid, whereas the biological functions of membrane and signalling lipids require that they only contain a small range of C16 and C18 fatty acids. One of the challenges to producing oilseeds with novel acyl compositions is therefore to maintain the segregation of exotic fatty acids away from pools of membrane or signalling lipids. Assembly of triacylglycerols: Triacylglycerols are assembled via a complex process involving sequential acylation of a glycerol moiety (the traditional Kennedy pathway) plus extensive acyl editing via phosphatidylcholine‐dependent desaturases or desaturase‐like enzymes (see earlier). The final conversion of DAG into TAG can occur via at least three enzymes: DGAT, acyl‐CoA dependent diacylglycerol acyltransferase; PDAT, phosphatidylcholine‐dependent acyltransferase or DGTA, diacylglycerol transacylase. Nascent TAG droplets are coated with a phospholipid monolayer into which is embedded an annulus of specific proteins, such as oleosins and caleosins, hence forming the mature storage oil bodies that are finally released into the cytosol. DAG, diacylglycerol; G3P, glycerol 3‐phosphate; MAG, monoacylglycerol; PA, phosphatidic acid and TAG, triacylglycerol.


Abbadi A, Domergue F, Bauer J, et al. (2004) Biosynthesis of very‐long‐chain polyunsaturated fatty acids in transgenic oilseeds: constraints on their accumulation. Plant Cell 16: 2734–2748.

Bates PD and Browse J (2012) The significance of different diacylglycerol synthesis pathways on plant oil composition and bioengineering. Frontiers in Plant Science 3: 147.

Baud S and Lepiniec L (2010) Physiological and developmental regulation of seed oil production. Progress in Lipid Research 49: 235–249.

van Beilen JB and Poirier Y (2008) Production of renewable polymers from crop plants. Plant Journal 54: 684–701.

Benatti P, Peluso G, Nicolai R and Calvani M (2004) Polyunsaturated fatty acids: biochemical, nutritional and epigenetic properties. Journal of the American College of Nutrition 23: 281–302.

Cahoon EB, Hall SE, Ripp KG, et al. (2003) Metabolic redesign of vitamin E biosynthesis in plants for tocotrienol production and increased antioxidant content. Nature Biotechnology 21: 1082–1087.

Gunstone FD (2011) Supplies of vegetable oils for non‐food purposes. European Journal of Lipid Science and Technology 113: 3–7.

Gunstone FD, Harwood JL and Dijkstra AJ (eds) (2007) The Lipid Handbook, 3rd edn, pp. 703–782. New York: Taylor and Francis.

Gurr M, Harwood JL, Mitchell R, Frayn KN and Murphy DJ (2016) Lipid Biology. Oxford: Blackwell, in press.

Han NM, May CY, Ngan MA, Hock CC and Ali Hashim M (2004) Isolation of palm tocols using supercritical fluid chromatography. Journal of Chromatographic Science 42: 536–539.

Haslam RP, Ruiz‐Lopez N, Eastmond P, et al. (2013) The modification of plant oil composition via metabolic engineering – better nutrition by design. Plant Biotechnology Journal 11: 157–168.

Hu Q, Sommerfeld M, Jarvis E, et al. (2008) Microalgal triacylglycerols as feedstocks for biofuel production: perspectives and advances. Plant Journal 54: 621–639.

Kubis SE, Pike MJ, Hill LM and Rawsthorne R (2004) The import of phosphoenolpyruvate by plastids from developing embryos of oilseed rape, Brassica napus (L.), and its potential as a substrate for fatty acid synthesis. Journal of Experimental Botany 55: 1455–1462.

Leprince O, van Aelst AC, Pritchard HW and Murphy DJ (1998) Oleosins prevent oil‐body coalescence during seed imbibition as suggested by a low‐temperature scanning electron microscope study of desiccation‐tolerant and ‐sensitive oilseeds. Planta 204: 109–119.

Lersten NR, Czlapinski AR, Curtis JD, Freckmann R and Horner HT (2006) Oil bodies in leaf mesophyll cells of angiosperms: overview and a selected survey. American Journal of Botany 93: 1731–1739.

Long SP, Karp A, Buckeridge MS, et al. (2015) Feedstocks for biofuels and bioenergy. In: Souza GM, Victoria RL, Joly CA and Verdade LM (eds) Scope Bioenergy & Sustainability: Bridging the Gaps, pp. 302–347. São Paulo: SCOPE.

Ma W, Kong Q, Arondel V, et al. (2013) WRINKLED1, a ubiquitous regulator in oil accumulating tissues from Arabidopsis embryos to oil palm mesocarp. PLoS One 8 (7): e68887.

Maeo K, Tokuda T, Ayame A, et al. (2009) An AP2‐type transcription factor, WRINKLED1, of Arabidopsis thaliana binds to the AW‐box sequence conserved among proximal upstream regions of genes involved in fatty acid synthesis. Plant Journal 60: 476–487.

Martin S and Parton RG (2006) Lipid droplets: a unified view of a dynamic organelle. Nature Reviews Molecular Cell Biology 7: 373–378.

Murphy DJ and Piffanelli P (1998) Fatty acid desaturases: structure mechanism and regulation. In: Harwood JL (ed) Plant Lipid Biosynthesis: Recent Advances of Agricultural Importance, pp. 95–1300. Cambridge: Cambridge University Press.

Murphy DJ and Vance J (1999) Mechanisms of lipid body biogenesis in animals and plants. Trends in Biochemical Science 24: 109–115.

Murphy DJ (2008) Future prospects for biofuels. Chemistry Today 26: 44–48.

Murphy DJ (2012a) Oil crops: a potential source of biofuel. In: Technological Innovations in Major World Oil Crops, Volume 2: Perspectives, pp. 269–284. Berlin: Springer.

Peng FY and Weselake RJ (2013) Genome‐wide identification and analysis of the B3 superfamily of transcription factors in Brassicaceae and major crop plants. Theoretical and Applied Genetics 126: 1305–1319.

Qi B, Fraser T, Mugford S, et al. (2004) Production of very long chain polyunsaturated omega‐3 and omega‐6 fatty acids in plants. Nature Biotechnology 22: 739–745.

Qu J, Ye J, Geng YF, et al. (2012) Dissecting functions of KATANIN and WRINKLED1 in cotton fiber development by virus‐induced gene silencing. Plant Physiology 160: 738–748.

Righelato R and Spracklen DV (2007) Carbon mitigation by biofuels or by saving and restoring forests. Science 317: 902.

Santos‐Mendoza M, Dubreucq B, Baud S, et al. (2008) Deciphering gene regulatory networks that control seed development and maturation in Arabidopsis. Plant Journal 54: 608–620.

Slocombe SP, Cornah J, Pinfield‐Wells H, et al. (2009) Oil accumulation in leaves directed by modification of fatty acid breakdown and lipid synthesis pathways. Plant Biotechnology Journal 7: 694–703.

Swaminathan K, Peterson K and Jack T (2008) The plant B3 superfamily. Trends in Plant Science 13: 647–655.

Tajima D, Kaneko A, Sakamoto M, et al (2013) Wrinkled 1 (WRI1) Homologs, AP2‐type transcription factors involving master regulation of seed storage oil synthesis in castor bean (Ricinus communis L.). American Journal of Plant Sciences 4: 333–339.

Thelen JJ and Ohlrogge JB (2002) Metabolic engineering of fatty acid biosynthesis in plants. Metabolic Engineering 4: 12–21.

To A, Joubès J, Barthole G, et al. (2012) WRINKLED transcription factors orchestrate tissue‐specific regulation of fatty acid biosynthesis in Arabidopsis. Plant Cell 24: 5007–5023.

Wu G, Truksa M, Datla N, et al. (2005) Stepwise metabolic engineering of economically significant amounts of very long chain polyunsaturated fatty acids in seeds of Brassica juncea. Nature Biotechnology 23: 1013–1017.

Further Reading

Murphy DJ (2012b) The dynamic roles of intracellular lipid droplets: from archaea to mammals. Protoplasma 249: 541–585.

Vanhercke T, Wood CC, Stymne S, Singh SP and Green AG (2013) Metabolic engineering of plant oils and waxes for use as industrial feedstocks. Plant Biotechnology Journal 11: 196–210.

Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
Murphy, Denis J(Feb 2016) Plant Storage Lipids. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0001918.pub3]