Transcriptome Comparison of Physaria (Lesquerella) fendleri and Camelina sativa Developing Seeds

Throughout the plant kingdom hundreds of species have evolved the ability to synthesize and accumulate a wide range of unusual fatty acid (FA) structures. Although genes responsible for FA modification have been identified, relatively little is known about how many and which lipid-associated genes have co-evolved to enable their accumulation at high levels in seeds. To better understand the evolution of new biochemical pathways for unusual FAs and address current limitations in engineering plants to produce high amounts of these value-added oils, we have used Illumina-based RNA-Seq approaches to investigate the transcript expression profiles from developing seeds of a native plant that accumulates high amounts of hydroxy FAs, Physaria fendleri, to Camelina sativa, a closely related plant that does not accumulate hydroxy FAs. We identified multiple lipid-associated gene candidates, many of which had not been previously considered, that appear to have co-evolved to enable hydroxy FA accumulation in Physaria. When applied to future engineering strategies these genes could improve the ability of transgenic commodity crops to accumulate these and other value-added oils.