Abstract: The synthesis of lignin by plants is controlled by transformation of the plant genome with a recombinant gene construct which contains the gene specifying an enzyme critical to the synthesis of a lignin precursor, which gene may be in antisense orientation so that it is transcribed to mRNA having a sequence complementary to the equivalent mRNA transcribed from the endogenous gene thus leading to suppression of lignin synthesis. If the recombinant gene has the lignin enzyme gene in normal, or "sense" orientation, increased production of the enzyme may occur when the insert is the full length DNA but suppression may occur if only a partial sequence is employed.