Abscisic acid metabolism and lipid accumulation of a cell suspension culture of Lesquerella fendleri

Lesquerella fendleri (commonly known as "Fendler's bladderpod" or "yellowtop") is a member of the Brassicaceae and is an important seed oil-producing plant. The lipid profile of L. fendleri seed indicates potential for producing a high quality replacement for castor oil. In this work, characterization of the lipid content of a suspension cell culture, derived from seedlings of L. fendleri, is provided. Under the described suspension cell culture conditions, 16:0, 18:1 Delta 9, 18:2 Delta 9, Delta 12 and 18:3 Delta 9, Delta 12, Delta 15 fatty acids were found to accumulate in the cells, while 16:0, 26:0 and 28:0 fatty acids were predominant in the culture medium. Subsequently, the effect of application of abscisic acid (ABA), which modulates lipid accumulation, was assessed. Exogenously applied ABA was taken up by the cells and metabolized via the conjugation pathway, resulting in the accumulation of ABA-glucose ester. Preliminary tests demonstrate the cell line is responsive to exogenous ABA, resulting in increased cellular lipid content and increased accumulation of lipids in the culture medium. This novel L. fendleri suspension culture presents a valuable model system for efficient characterization of mechanisms associated with ABA-induced accumulation of lipids.