Abstract: A method of producing a plant with novel starch-synthesising ability comprises stably incorporating into the genome of a recipient plant at least one target gene encoding an enzyme involved in a starch or glycogen biosynthetic pathway. A plant with novel starch-synthesising ability may have novel starch quality (eg altered fine structure). Starch or glycogen biosynthetic enzymes include soluble starch synthase, branching enzyme, glycogen synthase, ADP-glucose pyrophosphorylase, self-glucosylating protein, glycogenin and amylogenin. Mutants involving said enzymes for use in this method are described, including specific gene-dosage combinations which provide novel starch fine structures and starch properties. DNA constructs for use in this method are described, as well as plants transformed with said DNA constructs, the seeds and progeny of such plants, and hybrids whose pedigree includes such plants.