A protein (I) with the activity of wheat starch synthase is new. Independent claims are also included for the following: (1) a nucleic acid (II) or its derivatives or complement, encoding (I) (2) vectors (III) containing (II); (3) host cells that are transformed with (II) or (III), or are derived from such cells; (4) recombinant production of (I); (5) transgenic plant cells (IV) that are transformed with (I) or (III), or derived from such cells, where (I) is under control of regulatory sequences functional in plants; (6) plants that contain (IV), and their propagative materials; (7) transgenic plant cells (also plants and propagative materials) in which the activity of (II) has been inhibited; and (8) starch produced by the materials of (f)-(h).
