ABSTRACT
Guayule is a member of the sunflower family Compositae and belongs to the genus Parthenium. There are several species of Parthenium, and guayule is Parthenium argentatum, so designated because of a silvery sheen on its gray-green leaves. It is the only Parthenium species known to produce rubber in any quantity. The single major obstacle to commercial production of guayule rubber is the low yield of the guayule plant. A promising approach to improving the yield characteristics is through the bioregulation of the synthesis of polyisoprenoids to cause an accumulation of increased amounts of rubber. This approach is based on the discovery of bioregulators that appear to derepress specific genes, thereby inducing the production of additional quantities of constituents in plants. A series of bioregulators was developed for possible use in influencing rubber formation in guayule. Any improvement of yield in rubber in guayule must be accomplished without diminishing the physicochemical characteristics of rubber.
