| Title: | Flower color polymorphism in Iris lutescens (Iridaceae): biochemical analyses in light of plant-insect interactions |
| Author(s): | Wang H; Conchou L; Bessiere JM; Cazals G; Schatz B; Imbert E; |
| Address: | "Institut des Sciences de l'Evolution de Montpellier (ISEM), UMR 5554 CNRS-Universite Montpellier 2, Batiment 22, Universite Montpellier 2, place E. Bataillon, 34095 Montpellier Cedex 5, France" |
| DOI: | 10.1016/j.phytochem.2013.05.007 |
| ISSN/ISBN: | 1873-3700 (Electronic) 0031-9422 (Linking) |
| Abstract: | "We describe a flower color polymorphism in Iris lutescens, a species widespread in the Northern part of the Mediterranean basin. We studied the biochemical basis of the difference between purple and yellow flowers, and explored the ecological and evolutionary consequences of such difference, in particular visual discrimination by insects, a potential link with scent emitted and the association between color and scent. Anthocyanins were found to be present in much greater concentrations in purple flowers than in yellow ones, but the anthocyanin composition did not differ between color morphs. Likewise, no quantitative difference in anthocyanin content was found between vegetative tissues of the two morphs. Floral anthocyanins were dominated by delphinidin 3-O-(p-coumaroylrutinoside)-5-O-glucoside (also called delphanin) and its aliphatic derivatives. Small amounts of delphinidin 3-O-(p-caffeoylrutinoside)-5-O-glucoside and its aliphatic derivatives were also characterized. Based on a description of bumblebees' (one of the main pollinators of I. lutescens) color perception, purple and yellow flowers of I. lutescens could be visually discriminated as blue and blue-green, respectively, and likely by a wide variety of other insects. The overall chemical composition of the scent produced was not significantly different between morphs, being dominated by terpenoids, mainly myrcene, (E)-beta-ocimene and limonene. A slight color-scent correlation was nevertheless detected, consistent with the shared biosynthetic origin of both pigments and volatile compounds. Therefore in this species, the difference in the amounts of pigments responsible for flower color difference seems to be the major difference between the two morphs. Pollinators are probably the main selective agent driving the evolution of flower color polymorphism in I. lutescens, which represents a suitable species for investigating how such polymorphism is maintained" |
| Keywords: | "Acyclic Monoterpenes Alkenes/analysis/chemistry Animals Anthocyanins/analysis/chemistry Bees/physiology Biological Evolution Chromatography, High Pressure Liquid Color Flowers/*chemistry/parasitology Glucosides/analysis/chemistry Host-Parasite Interaction;" |
| Notes: | "MedlineWang, Hui Conchou, Lucie Bessiere, Jean-Marie Cazals, Guillaume Schatz, Bertrand Imbert, Eric eng Research Support, Non-U.S. Gov't England 2013/06/25 Phytochemistry. 2013 Oct; 94:123-34. doi: 10.1016/j.phytochem.2013.05.007. Epub 2013 Jun 18" |
