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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 1/17/2009 Publication Date: 2/1/2009 Citation: Chen, G.Q. 2009. Engineering of Hydroxyl Fatty Acids for Industrial Application. Gordon Research Conference, Plant Lipids: Structure, Metabolism and Function, Galveston, Texas, February 1 to 6, 2009. Interpretive Summary: The conventional source of hydroxyl fatty acid is from castor oil which 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. By suppressing the elongation step in L. fendelri through genetic engineering, it is possible to generate a L. fendleri crop producing ricinoleate. Technical Abstract: We conducted a series of seed development studies in castor and L. fendelri, 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. The 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 with the same time-course, which provides integrative information for understanding their relationships during the 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 a stabled transformation in L. fendleri. In general, we believe these 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. |
