Location: Bioproducts ResearchTitle: Biotechnology for safe hydroxy fatty acid production
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/18/2018
Publication Date: N/A
Technical Abstract: Castor is the conventional source of HFA, and 90% of castor oil is ricinoleic acid (18:1OH). HFA and its derivatives are used as raw materials for numerous industrial products, such as lubricants, plasticizers and surfactants. The production of castor oil, however, is hampered by the presence of the toxin ricin and hyperallergic 2S albumins. Lesquerella does not have such biologically toxic compounds and also contains a major HFA, lesquerolic acid (20:1OH), at 55-60% of seed oil. Therefore, lesquerella is being developed as a new industrial oilseed crop in the US. Biotechnology methods are effective for improving lesquerella through Agrobacteria-mediated genetic transformation. Lesquerella seed developmental studies show changes of morphology and physiology, as well as temporal details of fatty acid composition and gene expression patterns. Synthesis of 20:1OH is through elongation of 18:1OH, and the step is regulated largely by gene transcription of an elongase, PfKCS3. By silencing PfKCS3, transgenic lesquerella increased 18:1OH content from ~3% to ~27%. It is known that most of the HFAs in lesquerella are located only at sn1 and sn3 positions of triacylglycerols (TAG). To improve HFA levels in lesquerella seeds, a castor lysophosphatidic acid acyltransferase 2 gene (RcLPAT2) capable of acylating HFA to the sn2 position of TAGs was introduced into lesquerella. The resulted transgenic lesquerella seeds increased 18:1OH content at the sn2 position of TAG from 2% to 17%, and consequently, oil accumulated more TAGs with all three sn positions occupied by HFA. The results enhanced our understanding of plant lipid metabolism and provided invaluable guidance for future research, not only for enhancing HFA content in lesquerella, but also for HFA production in other oilseed crop.