2007 Annual Report 1a.Objectives (from AD-416) Produce multiple independent transgenic cell lines and plants of peanut by microprojectile bombardment of embryogenic tissues cultured in vitro. Test for tissue specific expression of genes driven by tissue specific gene promoters in transformed peanut. Test peanut tissues transformed with fungal resistance genes for resistance to Aspergillus flavus/parasiticus. 1b.Approach (from AD-416) Embryogenic plant cell lines will be bombarded with DNA (containing genes for kanamycin or hygromycin resistance as selective markers) and stably transformed peanut tissues selected for antibiotic resistance. The tissue/organ specific expression of a beta-glucuronidase reporter gene driven by a soybean vegetative storage protein gene promoter will be tested in transgenic Arachis hypogaea progeny of the T1 and T2 generations. Other promoter/reporter or promoter/antifungal gene combinations will be similarly tested. As fungal resistance genes become available from cooperators, these genes will be tested for their effectiveness in inhibiting growth of Aspergillus flavus/parasiticus in peanut tissues transformed with these genes. 3.Progress Report This report serves to document research conducted under a Specific Cooperative Agreement between the Agricultural Research Service (ARS) and the University of Georgia, Tifton. Additional details of research can be found in the report for the in-house project 6435-42000-019-00D, "Identification and Enhancement of Seed-Based Biochemical Resistance in Crops to Aflatoxin Producing Pathogens." Multiple genetic approaches to reduce aflatoxin contamination of peanut are being explored. Putative antifungal genes being tested include a chloroperoxidase gene (CPO-P) from a bacterium, Pseudomonas pyrrocinia. The CPO-P gene under the control of the gene expression trigger called the CaMV35S promoter, which was introduced into peanut by microprojectile bombardment, and multiple lines containing the gene, were tested for expression of the transgene. Expression was detected for both the direct gene expression product, ribonucleic acid (RNA), and protein. One line has been advanced for several generations, indicating that the gene insertion is stable and will be inherited in subsequent generations. This line also has shown a consistent 50 percent reduction in growth of the aflatoxin producing fungus, Aspergillus flavus, when seeds are inoculated in laboratory assays. The CPO-P line was planted in two aflatoxin tests in 2006. Each test contained 10 plots of the CPO-P line that were subjected to drought stress and will be assayed for aflatoxin production. Progress by cooperators was monitored through requiring routine teleconferencing, meetings, and scientific presentations of information relating to the project at professional society meetings, conferences and the Annual Aflatoxin Elimination Workshop sponsored by industry stakeholders.