Modification of sunflower oil quality by seed-specific expression of a heterologous Δ9-stearoyl-(acyl carrier protein) desaturase gene

Abstract

The coding sequence of Δ9-stearoyl-(acyl carrier protein) desaturase from Ricinus communis was introduced into sunflower, under the control of seed-specific promoter and terminator sequences of the late embryogenesis abundant gene from sunflower, Hads10. Two independent primary transformants contained three and six copies of the T-DNA, as demonstrated by hybridization using nptII as a probe. The transgene proved genetically stable and was transmitted as a Mendelian trait. Transcript analysis of the heterologous Δ9-stearoyl-(acyl carrier protein) desaturase under control of the Hads10 promoter verified tissue-specific expression in the developing embryos and not in the leaves. Fatty acid composition of the seed oil was followed over five generations under greenhouse and open field conditions. Some of the transgenic lines produced oil with a significantly reduced stearic acid content compared with non-transformed plants under greenhouse and field conditions. However, additional studies need to be performed to assess whether or not physiologically stable lines can be developed from these transgenic lines.