title: The characteristics and potential applications of structural lipid droplet proteins in plants.
abstract: Plant cytosolic lipid droplets are storage organelles that accumulate hydrophobic molecules. They are found in many tissues and their general structure includes an outer lipid monolayer with integral and associated proteins surrounding a hydrophobic core. Two distinct types can be distinguished, which we define here as oleosin-based lipid droplets (OLDs) and non-oleosin-based lipid droplets (NOLDs). OLDs are the best characterized lipid droplets in plants. They are primarily restricted to seeds and other germinative tissues, their surface is covered with oleosin-family proteins to maintain stability, they store triacylglycerols (TAGs) and they are used as a source of energy (and possibly signaling molecules) during the germination of seeds and pollen. Less is known about NOLDs. They are more abundant than OLDs and are distributed in many tissues, they accumulate not only TAGs but also other hydrophobic molecules such as natural rubber, and the structural proteins that stabilize them are unrelated to oleosins. In many species these proteins are members of the rubber elongation factor superfamily. NOLDs are not typically used for energy storage but instead accumulate hydrophobic compounds required for environmental interactions such as pathogen defense. There are many potential applications of NOLDs including the engineering of lipid production in plants and the generation of artificial oil bodies.
authors.affiliation: Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Schlossplatz 8, 48143 Münster, Germany. Electronic address: Natalie.Laibach@ime.fraunhofer.de.
authors.forename: Natalie
authors.initials: N
authors.lastname: Laibach
authors.affiliation: Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Schlossplatz 8, 48143 Münster, Germany. Electronic address: Janina.Post@ime.fraunhofer.de.
authors.forename: Janina
authors.initials: J
authors.lastname: Post
authors.affiliation: TRM Ltd, PO Box 93, York YO43 3WE, United Kingdom. Electronic address: richard@twymanrm.com.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Twyman
authors.affiliation: Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Schlossplatz 8, 48143 Münster, Germany. Electronic address: christian.schulze.gronover@ime.fraunhofer.de.
authors.forename: Christian Schulze
authors.initials: CS
authors.lastname: Gronover
authors.affiliation: Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Schlossplatz 8, 48143 Münster, Germany; Westphalian Wilhelms-University of Münster, Institute of Plant Biology and Biotechnology, Schlossplatz 8, 48143 Münster, Germany. Electronic address: dpruefer@uni-muenster.de.
authors.forename: Dirk
authors.initials: D
authors.lastname: Prüfer
mesh_terms: D001709:Biotechnology; D066292:Lipid Droplets; D010938:Plant Oils; D010940:Plant Proteins; D010944:Plants / Q000737:chemistry / Q000378:metabolism; D014280:Triglycerides
chemical_list: D010938:Plant Oils; D010940:Plant Proteins; D014280:Triglycerides
keywords: Artificial lipid droplets; Dual-use crops; Lipid-based drug delivery; Lipid-based formulations; Recombinant lipid-binding proteins; lipid droplets