Changes of Fatty Acids and Fatty Acid-Derived Flavor Compounds by Expressing the Yeast Δ-9 Desaturase Gene in Tomato

Expression of the yeast Δ-9 desaturase gene in tomato (Lycopersicon esculentum Mill.) led to changes in the levels of unsaturated as well as saturated fatty acids in tomato fruits. Increases in palmitoleic acid, 9,12-hexadienoic acid, and linoleic acid were observed. At the same time there was a reduction in palmitic acid and stearic acid. Changes in the profile of fatty acids were associated with changes in certain flavor compounds derived from fatty acids, most notably cis-3-hexenol, 1-hexanol, hexanal, and cis-3-hexenal. Certain flavor compounds not derived from fatty acids, viz. 6-methyl-5-hepten-2-one and 2-isobutylthiazole, also showed increases in transgenic fruits. These results show that changes in the levels of fatty acids in a plant could lead to changes in its profile of flavor compounds.