Comparative functional genomics of nectaries and nectars

The purpose of this site and corresponding databases is to disseminate results from our current project "Comparative functional genomics of nectaries and nectars in the dicots," which is funded through NSF's Plant Genome Research Program (Award #1339246)

Flowering plants attract mutualistic animals by offering a reward of nectar. Specifically, floral nectar (FN) is produced to attract pollinators, whereas extrafloral nectar (EFN) mediates indirect defenses (e.g. ant-plant interactions). There is a strong correlation between nectar quality (i.e. volume and composition) and the efficiency of the resulting plant-animal mutualism. Significantly, there is also a clear relationship between nectary form (the glands that produce nectar, Fig. 1) and nectar quality. Remarkably, the molecular events involved in the development of nectaries, as well as the synthesis and secretion of the nectar itself, are poorly understood. Indeed, only a few genes have been reported to directly affect the de novo production or quality of floral nectar.

This study is predicated on the hypothesis that nectar synthesis and secretion follows a central mechanism that is conserved among the core eudicots and applies to FN and EFN, and that this mechanism can be differentially regulated in different types of tissues, or species, in order to meet the physiological and ecological needs of the respective species. To test this hypothesis, the long-term goal of this research is to elucidate the genetic and physiological mechanisms that underlie nectary maturation and active nectar secretion, and to study the impact of selected nectar components on specific plant-animal interactions. In order to elucidate the conserved elements of these mechanisms we will apply a broad, comparative approach to the study of floral and extrafloral nectar/ies in a core group of dicotyledonous species (Brassica sp, cotton, tobacco, squash, Lima bean, and acacia; Table I). Determining the molecular basis of nectar production can have broad implications, ranging from understanding the co-evolution of plant-animal interactions to increasing yields in multiple crop species, as well as targeted improvements in apiculture.


June 2019: Erik Solhaug has published a new paper in Plant Physiology (in press) entitled Carbohydrate metabolism and signaling in squash nectaries and nectar throughout floral maturation. Congratulations, Erik!

May 2019: Congratulations to Drs. Elizabeth Chatt and Erik Solhaug for successfully defending their dissertations! Both are moving onto postdoctoral positions -- Elizabeth will be joining Prof. Rick Vierstra (WUSTL) in St. Louis and Erik will be moving to Switzerland to work in Prof. Sam Zeeman's lab (University of Zurich). We thank them for their hard work on this project and wish both the best of luck!

February 2019: New publication in Plant Direct: An integrated transcriptomics and metabolomics analysis of the Cucurbita pepo nectary implicates key modules of primary metabolism involved in nectar synthesis and secretion

August 2018: Elizabeth Chatt, Jason Thomas and Clay Carter gave talks at Plant Biology 2018 in Montreal

September 2018: New publication in Journal of Experimental Botany: The major nectar protein of Brassica rapa is a non-specific lipid transfer protein, BrLTP2.1, with strong antifungal activity. Congratulations to Tony Schmitt!

August 2018: New publications in Frontiers in Plant Science:

The octadecanoid pathway, but not COI1, is required for nectar secretion in Arabidopsis thaliana

Sex-dependent variation of pumpkin (Cucurbita maxima cv. Big Max) nectar and nectaries as determined by proteomics and metabolomics

Using nectar-related traits to enhance crop-pollinator interactions

New publication appearing in BMC Plant Biology: The pennycress (Thlaspi arvense L.) nectary: structural and transcriptomic characterization

New publication appearing in Plant Science: Nectar biology: From molecules to ecosystems

Publication appearing in Molecular Plant: A role for GIBBERELLIN 2-OXIDASE6 and gibberellins in regulating nectar production

Publication appearing in Nature: Nectar secretion requires sucrose phosphate synthases and the sugar transporter SWEET9

Publication featured on the cover of The Plant Journal: PIN6 is required for nectary auxin response and short stamen development

NOTE: This site also contains information from our prior study "Functional genomics of nectar production in the Brassicaceae," (NSF Award #0820730). The goal of this study was to identify genes, cellular structures, and molecular processes underlying nectar production in representative Brassicaceae (mainly Arabidopsis thaliana and Brassica rapa).