In animals, the gender of an individual and the gamete it produces is typically determined by a process that depends on specific chomosomes, such as the X and Y chromosomes in humans. Very little is known about this process in plants despte the fact that the production of gametes is essential for plants to reproduce. This project seeks to discover how plant gender is determined using a species whose gender is epigenetically determined by a chemical pheromone that is produced by hermaphroditic individuals and causes its neighbors to become male. To determine how the presence or absence of the pheromone determines gender type at the molecular level, all of the genes that are expressed throughout male and hermaphrodite development will be identified by sequencing expressed genes, and co-expression networks underlying gender determination and differentiation identified. Using a simple reverse genetics approach (RNAi), the functions of transcription factors that change significantly in their expression with respect to gender will be tested. The discovery of plant gender-determining genes has important implications in food production, as grain, fruit and seed production depend on a plant's ability to produce egg and sperm at the right time and place. The research described will be performed by undergraduate and graduate students, including members of groups underrepresented in science, providing them with training in biology, biochemistry, statistics, bioinformatics and critical thinking.