In previous work we have shown that the P gene regulates the accumulation of RNA from three genes of the flavonoid biosynthetic pathway. We have also shown that P encodes proteins with significant homology to the DNA binding domain of the c-myb family of oncogene proteins. Here, we propose a combined molecular, biochemical and genetic analysis of the regulatory function of the P gene products. We will generate antibodies against P proteins and use these to identify the P-encoded proteins and determine post-translational modifications may be involved in the regulatory function of P. The role of the P-encoded expression of the P transcripts in different maize tissues. The target sequences present in P regulated genes necessary for P regulation will be determined by functional testing and in vitro DNA binding assays. Finally, we will analyze mutations in the P-encoded proteins using two complementary in vivo systems. In the first, we will attempt to reproduce P regulation of a target gene in the yeast S. cerevisiae; if successful, this approach will facilitate rapid analysis of P regulation and allow the identification of transcription factors which interact with P. The second in vivo system examines P function in the maize plant using the transposable element Ac to generate mutant alleles at the specific sites in the P protein. Together, these results should help to reveal fundamental mechanisms by which a plant regulatory gene activates transcription.***//
