Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/18/2009
Publication Date: 6/6/2009
Citation: Chen, G.Q. 2009. Biotechnology for Castor oil Production. In Vitro Biology Meeting, Charleston, South Carolina, June 6-10, 2009. Interpretive Summary: Castor oil contains 90% ricinoleate (C18:1OH). Ricinoleate and its derivatives are used as raw material for numerous industrial products, such as lubricants, plasticizers and bio-diesel. However, the production of castor oil is hampered by the presence of the toxin ricin and hyper-allergenic 2S albumins in its seed. Lesquerella fendleri (L.) is a new oilseed crop whose seed contains lesquerolic acid (C20:1OH) derived from a 2 carbon elongation of ricinoleate. We are developing a ricinoleate-producing L. fendleri through suppression of the elongation step in L. fendleri using genetic engineering.
Technical Abstract: We conducted a series of seed development studies in castor and L. fendleri, including seed morphogenesis, oil and storage protein accumulation and lipid gene expression. In castor, the entire course of seed development can be divided into eight stages and each stage can be distinguished by seed coat color and volume of cellular endosperm. Synthesis of ricin, 2S albumin and ricinoleate/oil occurred during cellular endosperm development. Concomitantly, we observed increased transcript levels of 12 lipid genes involved in synthesis of ricinoleate/oil, but with various temporal patterns and different maximal induction ranging from 4- to 43,000-fold. These results indicate that gene transcription exerts a primary control in ricinloeate/oil biosyntheses, and there are different transcriptional regulatory mechanisms involved. Seed development in L. fendleri remains largely unknown. We have investigated the morphological (seed size and color), physiological (seed weight and germination) and biochemical (lipid and protein profile) changes during seed development. Our series of seed studies are all in parallel in the same time-course, which provides integrative information for understanding their relationships during seed development in L. fendleri. In order to genetically modify L. fendleri, we tested the transformation efficiency of leaf, root and stem tissues using Agrobacterium-mediated transformation technology. We have demonstrated stable transformation in L. fendleri. In general, we believe this transformation technology can be used not only to create a ricinoleate-producing crop, but also to improve L. fendleri as a superior crop with high yield and disease-resistance.