The invention relates to methods of increasing the total oil content and/or the glycerol 3-phosphate content in transgenic oil crop plants which comprise at least 20% by weight of oleic acid based on the total fatty acid content, preferably in plant seeds, by expressing glycerol 3-phosphate dehydrogenases (G3PDHs) from yeasts, preferably from Saccharomyces cerevisiae. The oil and/or the free fatty acids obtained in the process are advantageously added to polymers, foodstuffs, feedstuffs, cosmetics, pharmaceuticals or products with industrial applications.