RNA EXPRESSION IN SUNFLOWER FATTY ACID MUTANTS PROVIDES INSIGHT INTO FATTY ACID SYNTHESIS

¹ Oregon State University, Crop Science Building, Corvallis, OR, 97331

As more data about the biological effects of various fatty acids accrues, the demand for oils with specific fatty acid profiles is likely to increase. Sunflower breeders have fatty acid mutants that are useful for altering the profiles, but the phenotypic expression of these mutants is often complex and quantitatively inherited. One of the interests in our lab is to identify genes in the glycerolipid synthesis pathway that play key roles in the accumulation of various fatty acids, and identify non-allelic mutants that can provide novel additive or synergistic effects on the phenotype. An RNA expression array is a suitable approach to identify key genes, provided that the gene transcripts are regulated. We have developed a microarray from 42 glycerolipid related ESTs, and surveyed for differential RNA expression of high oleic and low saturated fat mutants in sunflower developing kernels. We detected variable transcript levels from some ESTs that are consistent with previous expression studies, such as the under-expression of the oleate desaturase in high oleic mutants. Other differentially expressed ESTs were detected that may not have been predicted otherwise. These could represent differences necessary for the phenotype, or background idiosyncrasies not related to the fatty acid phenotype.