The specification relates to plants and their seeds and oil obtained therefrom, and to methods of producing same comprising oil having modified fatty acid compositions, such that 28% to 80% of the total fatty acid content in the seedoil is palmitic acid, 0% to 16% is palmitoleic acid, 0% to 4% is C16:2 fatty acid, 3% to 33% is stearic acid, 1% to 40% is oleic acid, 4% to 50% is linoleic acid and 0% to 10% is linolenic acid. The specification describes nucleic acid molecules encoding RNA capable of conferring these properties, in particular, RNA that inhibits expression of an oil biosynthesis gene encoding KASII in seeds of a plant. Genetic constructs and cells comprising the nucleic acid molecules are also described and claimed.