Martínez-Harms Jaime, Warskulat Anne-Christin, Dudek Bettina, Kunert Grit, Lorenz Sybille, Hansson Bill S, Schneider Bernd
Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, 07745, Jena, Germany.
Current address: Instituto de Investigaciones Agropecuarias, INIA-La Cruz, Chorrillos 86, La Cruz, 2280454, Chile.
Chembiochem. 2018 Jul 16;19(14):1553-1562. doi: 10.1002/cbic.201800155. Epub 2018 Jun 17.
Despite increasing evidence for biosynthetic connections between flower pigments and volatile compounds, examples of such relationships in polymorphic plant species remains limited. Herein, color-scent associations in flowers from Papaver nudicaule (Papaveraceae) have been investigated. The spectral reflectance and scent composition of flowers of four color cultivars was determined. We found that pigments and volatiles occur in specific combinations in flowers of P. nudicaule. The presence of indole in the bouquets is strongly associated with the occurrence of yellow pigments called nudicaulins, for which indole is one of the final biosynthetic precursors. Whereas yellow flowers emit an excess of indole, orange flowers consume it during nudicaulin production and lack the substance in their bouquet. By using the honeybee, Apis mellifera, evaluations were made on how color and scent affect the discrimination of these flowers by pollinators. Honeybees were able to discriminate artificial odor mixtures resembling those of the natural flower odors. Bees trained with stimuli combining colors and odors showed an improved discrimination performance. The results indicate that the indole moiety of nudicaulins and emitted indole might be products of the same biochemical pathway. We propose that conserved pathways account for the evolution of color-scent associations in P. nudicaule and that these associations positively affect flower constancy of pollinators.
尽管有越来越多的证据表明花色素与挥发性化合物之间存在生物合成联系，但多态植物物种中这种关系的实例仍然有限。在此，对裸茎罂粟（罂粟科）花朵中的颜色 - 气味关联进行了研究。测定了四个颜色品种花朵的光谱反射率和气味成分。我们发现，在裸茎罂粟的花朵中，色素和挥发物以特定组合出现。花束中吲哚的存在与名为裸茎素的黄色色素的出现密切相关，吲哚是裸茎素最终生物合成前体之一。黄花会释放过量的吲哚，而橙花在裸茎素产生过程中会消耗吲哚，其花束中缺乏这种物质。通过利用蜜蜂（意大利蜜蜂），评估了颜色和气味如何影响传粉者对这些花朵的辨别。蜜蜂能够区分类似于天然花香气味的人工气味混合物。用颜色和气味组合的刺激物训练的蜜蜂表现出更好的辨别能力。结果表明，裸茎素的吲哚部分和释放的吲哚可能是同一生化途径的产物。我们提出，保守的途径解释了裸茎罂粟中颜色 - 气味关联的进化，并且这些关联对传粉者的花恒性有积极影响。
