hpRNA-mediated targeting of the Arabidopsis FAD2 gene gives highly efficient and stable silencing.

The endogenous Delta 12-desaturase gene (FAD2) in Arabidopsis was targeted for silencing using seed-specific cosuppression (CS), hairpin (HP) RNA (hpRNA), and intron-spliced HP (iHP) constructs. The iHP construct, incorporating the 120-bp 3'-untranslated region of the FAD2 gene, gave the highest degree of silencing. In some iHP lines Delta 12-desaturase activity was reduced to levels as low as those in the null fad2-1 mutant, and every primary transformant showed a pronounced reduction in FAD2 activity.