High-oleic acid Australian Brassica napus and B-juncea varieties produced by co-suppression of endogenous Delta 12-desaturases

Genetic engineering methods have been used successfully to modify the fatty acid profile of elite Australian germplasm of Brassica napus and B. juncea . Go-suppression plasmids carrying oleate desaturase genes from each specie s have been constructed and transferred into Australian elite breeding line s of B. napus and B. juncea using Agrobacterium tumifaciens plant-transform ation techniques. Modifications to existing Brassica transformation protoco ls and the use of an intron-interrupted hygromycin-resistance gene as the s electable marker have resulted in improved transformation efficiencies. Sil encing of the endogenous oleate desaturase genes has resulted in substantia l increases in oleic acid levels, up to 89 % in B. napus and 73 % in B. jun cea.