9513475 Bustos The aim of this research is to characterize the function of transcriptional activators and repressors that regulate expression of storage protein genes during early stages of seed maturation. A gene, PvALF, encoding an acidic transcription activator has been isolated. In French bean, PvALF activates gene expression from PHS( and DLEC2 promoters. Also factors ROM1 and ROM2, both basic/leucine-zipper proteins, which act as DNA binding site-dependent repressors of PvALF-activated transcription have been isolated. Specific aims will be to investigate the cis-acting DNA signals that mediate transactivation by PvALF or transrepression by ROM1 and ROM2. Additionally, the spatial distribution and regulation of ROM1 and ROM2 gene expression in plant embryos will be characterized, and a plant transformation procedure will be utilized to test whether ROM1 and ROM2 also restrict PHS( and DLEC2 expression to specialized storage cells of the embryo and cotyledons. %%% Plants produce storage proteins that are contained within seeds which can be used by humans and other animals as food. This process occurs during seed development by the production of specialized gene regulating proteins. These regulatory proteins recognize certain DNA sequences near the genes that code for food proteins. The regulatory proteins activate the rate that the enzymatic machinery produces the blueprints or messages for food protein production. This is part of the developmental process of seed production. After the seed proteins are produced there appears another group of specialized proteins which bind to DNA sequences near the gene and stop or repress the production of food protein messages. This project will study how both the activation and repression proteins interact with DNA in plants to turn on or off the synthesis of food storage proteins. ***
