Bioassembly of acyl lipids in microspore-derived embryos of Brassica campestris L.

Par Conseil national de recherches du Canada

DOI	Trouver le DOI : https://doi.org/10.1007/BF00234696
Auteur	Rechercher : Taylor, D.C.¹; Rechercher : Ferrie, A.M.R.¹; Rechercher : Keller, W.A.¹; Rechercher : Giblin, E.M.¹; Rechercher : Pass, E.W.¹; Rechercher : MacKenzie, S.L.¹
Affiliation	Conseil national de recherches du Canada. Institut de biotechnologie des plantes du CNRC
Format	Texte, Article
Sujet	Brassica campestris; microspore; derived embryos; acyl lipid biosynthesis
Résumé	The native lipid composition and the capacity of cell-free extracts to biosynthesize acyl lipids in vitro were determined for the first time using the recently reported microspore-derived (MD) embryo system from the Brassica campestris low erucic acid line BC-2 (Baillie et al. 1992). The total lipid fraction isolated from midcotyledonary stage MD embryos (21 days in culture) was composed primarily of triacylglycerol (76%) with an acyl composition quite similar to that of mature BC-2 seed. When incubated in the presence of glycerol-3-phosphate, ¹⁴C 18∶1-CoA, and reducing equivalents, homogenates prepared from 21-day cultured MD embryos were able to biosynthesize glycerolipids via the Kennedy pathway. The maximum in vitro rate of triacylglycerol biosynthesis could more than account for the known rate of lipid accumulation in vivo. The homogenate catalyzed the desaturation of 18∶1 to 18∶2 and to a lesser extent, 18∶3. The newly-synthesized polyunsaturated fatty acids initially accumulated in the polar lipid fraction (primarily phosphatidic acid and phosphatidylcholine) but began to appear in the triacylglycerol fraction after longer incubation periods. As expected for a low erucic acid cultivar, homogenates of MD embryos from the BC-2 line were incapable of biosynthesizing very long chain monounsaturated fatty acyl moieties (20∶1 and 22∶1) from 18∶1-CoA in vitro. Nonetheless, embryo extracts were still capable of incorporating these fatty acyl moieties into triacylglycerols when supplied with ¹⁴C 20∶1-CoA or ¹⁴C 22∶1-CoA. Collectively, the data suggest that developing BC-2 MD embryos constitute an excellent experimental system for studying pathways for glycerolipid bioassembly and the manipulation of this process in B. campestris.
Date de publication	1993-05
Maison d’édition	Springer Nature
Dans	Plant Cell Reports 12-12, nº 7-8 (mai 1993).
Langue	anglais
Publications évaluées par des pairs	Oui
Identificateur	BF00234696 NRCC-35896
Exporter la notice	Exporter en format RIS
Signaler une correction	Signaler une correction (s'ouvre dans un nouvel onglet)
Identificateur de l’enregistrement	e29b8257-e8ac-497c-80b8-452083b5cd1d
Enregistrement créé	2023-11-06
Enregistrement modifié	2023-11-06

Date de modification :: 2024-07-28