Mostly expressed in stems, and, at low levels, in roots and leaves, but barely in flowers. The Asp-Xaa-Asp-Asp (DXDD) motif is important for the catalytic activity, presumably through binding to Mg(2+). Belongs to the terpene synthase family. Tpsc subfamily. Probably inactive enzyme; missing the second Asp of the DXDD motif that has been reported to be essential in forming hydrogen-bonded 'proton wires' during catalysis.