Discloses a method for modulating the level of (1,31,4)-ß-D-glucan produced by a nonhuman cell, the method comprising modulating the level of expression and/or activity of a CsIH-encoded (1,31,4)-ß-D-glucan synthase in the cell. Discloses transgenic plants (e.g. cereal crop plants) comprising cells modified by the method disclosed. An isolated CsIH nucleic acid or a fragment thereof which is at least 94 % identical to SEQ ID NO:1 is disclosed. Further disclosed is an antibody or epitope binding fragment raised against the protein encoded by SEQ ID NO: 1.