Involved in monoterpene (C10) biosynthesis. The major product is (S)-linalool. (2E)-geranyl diphosphate + H2O = (S)-linalool + diphosphate Binds 3 Mg(2+) or Mn(2+) ions per subunit. Secondary metabolite biosynthesis; terpenoid biosynthesis. A number of isoforms are produced. According to EST sequences. Predominantly expressed in flowers but also in stems and siliques. The Asp-Asp-Xaa-Xaa-Asp/Glu (DDXXD/E) motif is important for the catalytic activity, presumably through binding to Mg(2+). Belongs to the terpene synthase family. Tpsb subfamily.