Abstract: The invention relates to DNA sequences which code for a protein having the enzymatic activity of a &bgr;-ketoacyl ACP synthase (KAS) of the enzyme complex of the fatty acid synthase (FAS). The invention also relates to transgenic plants and micro-organisms which contain nucleic acid sequences which code for proteins having the activity of a &bgr;-ketoacyl ACP ((acyl carrier protein)) synthase (KAS) of the enzyme complex of the fatty acid synthase (FAS). The invention further relates to a method for influencing the fatty acid pattern and/or for increasing the fatty acid content, especially the content of short and middle chain fatty acids, in plants, especially in seed tissues that synthesize and/or store triacylglycerols, as well as in micro-organisms, especially bacteria and algae. The inventive method comprises the expression of proteins having the activity of a KAS of the enzyme complex or the fatty acid synthase in transgenic plants or micro-organisms.

Abstract: The invention relates to nucleic acid molecules that encode a protein with the activity of a &bgr;-ketoacyl-ACP synthase IV (KASIV) from Cuphea lanceolata, to nucleic acid molecules that encode a protein with the activity of a &bgr;-ketoacyl-ACP synthase II (KASII) from Brassica napus, and to nucleic acid molecules that encode a protein with the activity of a &bgr;-ketoacyl-ACP synthase I (KASI) from Cuphea lanceolata. The invention further relates to a method of increasing the content of fatty acids, especially of short- and medium-chain fatty acids in triglycerides of plant seeds. The inventive method comprises expressing a protein with the activity of KASII or a protein with the activity of KASIV in transgenic plant seeds.