Inverted-repeat DNA: a new gene-silencing tool for seed lipid modification.

Post-transcriptional gene silencing (PTGS) has been successfully used to modify seed lipids in oilseed crops like soybean, canola and sunflower. Conventionally, PTGS has been induced by transforming the plants with either antisense or co-suppression constructs targeted against key seed lipid biosynthesis genes. A major drawback of this approach has been the recovery of only a modest proportion of silenced individuals from large populations of transgenic plants. In this report we show that inverted-repeat DNA constructs containing an intron encoding RNA with a hairpin structure can induce PTGS with very high frequency.