Oecologia

, Volume 155, Issue 3, pp 539–547

Chemical differences between seeds and elaiosomes indicate an adaptation to nutritional needs of ants

  • Renate C. Fischer
  • Andreas Richter
  • Franz Hadacek
  • Veronika Mayer
Plant-Animal Interactions - Original Paper

DOI: 10.1007/s00442-007-0931-8

Cite this article as:
Fischer, R.C., Richter, A., Hadacek, F. et al. Oecologia (2008) 155: 539. doi:10.1007/s00442-007-0931-8

Abstract

Ant-dispersed plants usually produce seeds with appendages (elaiosomes) as reward for ants. Plants that produce high-quality elaiosomes benefit because ants preferentially disperse their diaspores. We therefore hypothesized that seeds and elaiosomes differ in chemical composition in ways that make elaiosomes of high nutritional quality for ants, capable of providing essential dietary components that explain the increased fitness and higher gyne production documented for colonies with elaiosome consumption. To test the hypothesis we analysed the content and composition of lipids, amino acids, soluble carbohydrates, proteins and starch in seeds and elaiosomes of 15 central European ant-dispersed plants. After separating the different fractions, total lipids were determined gravimetrically, fatty acids and soluble carbohydrates were detected by gas chromatography (GC) and GC–mass spectrometry, free amino acids by an amino acid analyser while starch and protein were analysed photometrically. Seeds accumulated high molecular weight compounds such as proteins and starch, whereas elaiosomes accumulated more easily digestible low molecular weight compounds such as amino acids and monosaccharides. Analysis of similarities and similarity percentages analysis demonstrated that the composition of fatty acids, free amino acids and carbohydrates differed markedly between elaiosomes and seeds. The most important difference was in total amino acid content, which was on average 7.5 times higher in elaiosomes than in seeds. The difference was especially marked for the nitrogen-rich amino acid histidine. The availability of essential nutrients and, in some species, the higher nitrogen content in elaiosomes suggest that their nutritional value for larvae plays a key role in this interaction.

Keywords

Ant–plant interactionElaiosomeMyrmecochoryNutrientsSeed dispersal

Supplementary material

442_2007_931_MOESM1_ESM.doc (34 kb)
(DOC 33 kb)
442_2007_931_MOESM2_ESM.doc (34 kb)
(DOC 34 kb)
442_2007_931_MOESM3_ESM.doc (25 kb)
(DOC 25 kb)

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Renate C. Fischer
    • 1
    • 2
  • Andreas Richter
    • 2
  • Franz Hadacek
    • 2
  • Veronika Mayer
    • 1
  1. 1.Department of Palynology and Structural Botany, Faculty Centre of BotanyUniversity of ViennaViennaAustria
  2. 2.Department of Chemical Ecology and Ecosystem Research, Vienna Ecology CentreUniversity of ViennaViennaAustria