Functional Genomics of Nectar Production in the Brassicaceae
An organ known as the floral nectary is responsible for producing nectar in many plant families. Despite its central role in plant pollination, very little is known about the molecular mechanisms of nectar synthesis and secretion. Indeed, no genes have been shown to directly affect the production or quality of floral nectar. The overall goal of this project is to identify key genes and cellular processes required for nectar production in the agriculturally important Brassicaceae family. In previous studies, seventy genes from the model plant Arabidopsis thaliana were shown to be expressed at greater than 10-fold higher levels in nectaries than in all other tissues examined. The roles these genes play in nectar production will be systematically examined in both Arabidopsis and Brassica rapa (oilseed rape) through gene knockout and overexpression studies. Mutant plants will be subjected to thorough phenotypic characterization that includes evaluation of nectary morphology and ultrastructure, global changes in gene expression within nectaries, and overall impacts on nectar volume and composition. It is expected that these studies will provide new insight into the genes and pathways required for nectar production in plants.