Abstract.
Microsomal preparations from developing castor bean (Ricinus communis L.) endosperm catalyzed remodelling of in-situ-formed triacylglycerol (TAG) species. Castor bean microsomal membranes synthesized [14C]TAGs from either glycerol 3-phosphate and [14C]ricinoleoyl-CoA or [14C]glycerol 3-phosphate and ricinoleoyl-CoA. Upon repelleting and subsequent incubation of the microsomes a redistribution occurred of both the [14C]glycerol and [14C]ricinoleoyl moieties of the in-situ-synthesized [14C]TAGs. Radioactivity was transferred from TAG species with three (3HO-TAG) or two (2HO-TAG)ricinoleoyl groups into species with two or one (HO-TAG) ricinoleoyl groups. Mass analysis of the lipid and fatty acid movements in the membranes showed that a net synthesis of TAGs with no, one and two ricinoleoyl groups occurred at the expense of 3HO-TAG and polar lipids. Thus, the non-hydroxylated acyl groups from polar lipids were used in the remodelling of TAGs. In-vivo feeding of [14C]ricinoleic acid to slices of castor bean endosperm demonstrated the presence of two radioactive pools of TAGs one in the oil bodies, which was rich in [14C]3HO-TAG, and one associated with the microsomal membranes, which was dominated by radioactive 1HO-TAG and 2HO-TAG. The microsomal TAG pool was remodelled in vivo in a similar way as in the in-vitro experiments with microsomal membranes.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 8 November 1996 / Accepted: 5 February 1997
Rights and permissions
About this article
Cite this article
Mancha, M., Stymne, S. Remodelling of triacylglycerols in microsomal preparations from developing castor bean (Ricinus communis L.) endosperm. Planta 203, 51–57 (1997). https://doi.org/10.1007/s00050164
Issue Date:
DOI: https://doi.org/10.1007/s00050164