Major: Plant Biology 

Major Professor: Dr. Basil Nikolau

Department of Biochemistry, Biophysics and Molecular Biology

"Integrated ‘Omics’ Characterization of Conserved Nectar Production Mechanisms Using Floral and Extrafloral Eudicot Nectaries"

Floral and extrafloral nectar, produced by nectaries, is offered as a reward to foster plant-animal mutualisms with pollinators and invertebrate predators. Attraction of pollinators through floral nectar improves fruit set in 87 out of 115 global food crops. Meanwhile extrafloral nectar, reported in 745 genera, attracts invertebrate predators, such as ants, wasps, and spiders, as an indirect defense mechanism to reduce herbivory. Nectar quality (i.e. volume and composition) strongly correlates with the efficiency of these plant-animal mutualisms, yet nectar composition has typically only been defined by targeted analyses of the two most predominant classes of metabolites, carbohydrates and amino acids. Other less abundant components of nectar are unaccounted (i.e. vitamins, alkaloids, phenolics, terpenoids, lipids, metal ions, hormones, and proteins). Furthermore, molecular understanding of nectar synthesis and secretion is limited to a few reports of genes directly affecting the de novo production or quality of floral nectar.

Comprehensive GC-MS based metabolomics techniques capable of quantifying trace components of nectar were used to characterize nectar composition from species, spanning three eudicot families (Cucurbitaceae, Malvaceae, and Solanaceae). This enabled examination of relationships between nectar composition and biological factors such as the sex of the flower, plant-animal mutualisms, and functional role of the nectar regarding plant reproductive success and defense (i.e. floral and extrafloral nectar).