Dehydroabietinal (DA), an abietane diterpenoid, is a bioactive plant metabolite. DA promotes the transition from the vegetative to the reproductive phase of growth (producing flowers) in Arabidopsis by repressing expression of the flowering repressor FLOWERING LOCUS C (FLC) and upregulating expression of the flowering time promoter FLOWERING LOCUS D (FLD). To further understand the mechanism underlying signaling by DA, we have identified an Arabidopsis thaliana DA resistant mutant ems2-7 that exhibits delayed flowering and stunted growth. DA application was unable to promote flowering time in the ems2-7 mutant. Genetic analysis followed by sequencing indicated linkage of the delayed flowering phenotype to the dar1-1 mutation in a gene that encodes a putative O fucosyltransferase. However, the corresponding wild type DAR1 gene when transformed into the dar1-1 mutant did not complement the delayed flowering phenotype of ems2-7, thus indicating that the dar1-1 mutation is not responsible for the delayed flowering phenotype of the ems2-7 mutant. The goal of this project is to identify the gene associated with the delayed flowering phenotype of ems2-7. We hypothesize that a second site mutation that is physically linked to the dar1-1 allele is responsible for the delayed flowering phenotype of the ems2-7 mutant. As a first step towards testing this hypothesis, we set out to segregate the mutation responsible for the flowering defect away from the dar1-1 allele.