Compositions and methods include genetically encoding and expressing a novel delta-9 desaturase in plant cells. In some embodiments, methods of expressing nucleic acids in a plant cell to take advantage of the delta-9 desaturase enzyme's activity, such that the percent composition of saturated fatty acids in plant seeds is decreased and there is a concomitant increase in Δ9 fatty acids. In other embodiments, amino acid sequences have delta-9 desaturase activity. Methods can involve expression of delta-9 desaturase in plant cells, plant materials, and whole plants for the purpose of increasing the amount of mono unsaturated fatty acids in whole plants, plant seeds, and plant materials, for example, seeds.