CASTOR SEED DEVELOPMENT AND STORAGE LIPID BIOSYNTHESIS

Authors: Chen, Grace; Ahn, Yeh Jin; Vang, Louisa

Submitted to: In Vitro Cellular and Developmental Biology - Plants
Publication Type: Abstract Only
Publication Acceptance Date: 5/15/2006
Publication Date: 6/2/2006
Citation: Chen, G.Q., Ahn, Y., Vang, L. 2006. Castor seed development and storage lipid biosynthesis. In Vitro Cellular and Developmental Biology - Plants.

Interpretive Summary: Castor seed triacylglycerols (TAGs) contains 90% ricinoleate (12-hydroxy-oleate) and is the only commercial source of hydroxy fatty acid that has numerous industrial applications. Due to the presence of ricin toxin and hyper-allergenic 2S albumins in the seed, it is desirable to produce ricinoleate from amenable oilseeds. We are investigating enzymatic genes or regulatory genes that may up-regulate multiple activities or entire pathways leading to the ricinoleate and TAG syntheses.

Technical Abstract: To identify additional enzymatic genes or regulatory genes that may up-regulate multiple activities or entire pathways leading to the ricinoleate and TAG syntheses in castor. we have analyzed expression profiles of twelve castor lipid genes. A series of castor seeds with well-defined developmental stages and morphologies were used to determine the mRNA levels of the lipid genes; in parallel, contents of the ricinoleate and TAG were also measured in the same set of developing seeds. Next, we performed a clustering analysis for the expression data that allows identify five gene groups each with a distinct temporal pattern. Based on our data and a basic working knowledge of gene transcription, we propose a model that accounts for the observed variations among clusters as well as the shared characteristics between clusters during certain stages of seed development.