Naturwissenschaften

, Volume 93, Issue 2, pp 72–79

A novel role for proline in plant floral nectars

  • Clay Carter
  • Sharoni Shafir
  • Lia Yehonatan
  • Reid G. Palmer
  • Robert Thornburg
Original Article

DOI: 10.1007/s00114-005-0062-1

Cite this article as:
Carter, C., Shafir, S., Yehonatan, L. et al. Naturwissenschaften (2006) 93: 72. doi:10.1007/s00114-005-0062-1

Abstract

Plants offer metabolically rich floral nectar to attract visiting pollinators. The composition of nectar includes not only sugars, but also amino acids. We have examined the amino acid content of the nectar of ornamental tobacco and found that it is extremely rich (2 mM) in proline. Because insect pollinators preferentially utilize proline during the initial phases of insect flight and can reportedly taste proline, we determined whether honeybees showed a preference for synthetic nectars rich in proline. We therefore established an insect preference test and found that honeybees indeed prefer nectars rich in the amino acid proline. To determine whether this was a general phenomenon, we also examined the nectars of two insect-pollinated wild perennial species of soybean. These species also showed high levels of proline in their nectars demonstrating that plants often produce proline-rich floral nectar. Because insects such as honeybees prefer proline-rich nectars, we hypothesize that some plants offer proline-rich nectars as a mechanism to attract visiting pollinators.

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • Clay Carter
    • 1
    • 2
  • Sharoni Shafir
    • 3
  • Lia Yehonatan
    • 3
  • Reid G. Palmer
    • 4
  • Robert Thornburg
    • 1
  1. 1.Department of Biochemistry, Biophysics and Molecular Biology 2212 Molecular Biology BuildingIowa State UniversityAmesUSA
  2. 2.Department of BiologyUniversity of Minnesota DuluthDuluthUSA
  3. 3.B. Triwaks Bee Research Center, Department of Entomology, Faculty of Agricultural, Food and Environmental Quality SciencesThe Hebrew University of JerusalemRehovotIsrael
  4. 4.United States Department of Agriculture-Agricultural Research Service G301 Agronomy HallIowa State UniversityAmesUSA