Root and seedling rot caused by P. sojae is the most important soybean disease in Ohio. Various viruses were modified into tools to examine genes that confer resistance to P. sojae (Rps genes). Earlier virus-induced gene silencing (VIGS) vectors had serious shortcomings that limited their wider use. With previous OSC support, a superior VIGS vector, designated FZ, has been developed. Here we propose to use FZ to accomplish four goals. First, we will interrogate candidates of Rps1c, Rps3a, and Rps8 to unveil their true nature. Second, we will use FZ to express P. sojae effectors to simplify screening of new Rps genes. Third, we will augment P. sojae resistance by enhancing flavonoid production. Finally, we will test a faster and simpler method for soybean delivery of FZ constructs. This project fits OSC mission of investing soybean checkoff funds to maximize the value of soybeans and increase profit opportunities for Ohio farmers, and addresses OSC Strategic Goal of Driving Innovation.