2006 Annual Report 4d.Progress report. This report documents a Non-Funded Cooperative Agreement between USDA-ARS and the University of California-Berkeley. Additional information can be found in the report of the parent CRIS 5442-21220-017-00D, Biologically Based Weed Management: Fundamental Research on Dormancy and the Genetics of Weeds. The objectives of this collaboration are to identify the genes responsible for production of the diterpenoid precursors to prostratin (12-deoxyphorbol 13-acetate) and DPP (12-deoxyphorbol 13-phenylacetate) from genetic libraries originating from Euphorbia esula. These related compounds have recently shown great potential for the treatment of HIV. The supplies of prostratin and DPP are limited, as they both originate from uncommon Euphorbiaceae plant sources, and chemical synthesis routes have not been devised. The USDA-ARS is providing genetic material, sequence information, and expertise for Euphorbia esula and the University of California is currently using these resources and information to isolate full-length candidate genes which will be engineered for expression into suitable microbial hosts to test for their value in synthesis of diterpenoid precursors. So far, two full length TerPene Synthase genes (TSP1 and TSP2) have been isolated and cloned into both E. coli and yeast.