'Do pollinators play a role in shaping the essential amino acids found in nectar?' - data and analyses

Data and scripts accompanying the publication Do pollinators play a role in shaping the essential amino acids found in nectar?Rachel H. Parkinson1, Eileen F. Power2, Kieran Walter1, Alex E. McDermott-Roberts1, Jonathan G. Pattrick1, and Geraldine A. Wright1Affiliations: 1Department of Biology, University of Oxford; 2Newcastle University, Institute of Neuroscience.SummaryPlants produce floral nectar as a reward for pollinators, which contains carbohydrates and amino acids (AAs). We designed experiments to test whether pollinators could exert selection pressure on the profiles of AAs in nectar.We used HPLC to measure the free amino acids and sugars in the nectar of 102 UK plant species. Six distinct profiles of essential amino acids (EAAs) were defined using the relative proportions of AAs with a clustering algorithm; we then tested bumblebee (Bombus terrestris) preferences for the EAA profiles and proline using a two-choice assay.We found a phylogenetic signal for the proportions of phenylalanine, methionine and proline as well as the total concentrations of essential and non-essential AAs. However, there was no phylogenetic signal for EAA profile. Bumblebees did not exhibit a preference for any of the six EAA nectar profiles, however, four of the EAA profiles stimulated feeding. In contrast, bumblebees avoided proline in an inverse concentration-dependent manner.Our data indicate that bees are likely to have mechanisms for the post-ingestive evaluation of free AAs in solution but are unlikely to taste EAAs at nectar-relevant quantities. We predict that EAAs increase nectar value to bumblebees post-ingestively.

随《Do pollinators play a role in shaping the essential amino acids found in nectar?》一文的发表所附带的资料与脚本。Rachel H. Parkinson（1）、Eileen F. Power（2）、Kieran Walter（1）、Alex E. McDermott-Roberts（1）、Jonathan G. Pattrick（1）及Geraldine A. Wright（1）共同完成。所属机构：1牛津大学生物学系；2纽卡斯尔大学神经科学研究所。摘要：植物生产花蜜作为对传粉者的奖励，其中包含碳水化合物和氨基酸（AAs）。本研究旨在验证传粉者是否能够对花蜜中氨基酸（AAs）的组成施加选择压力。我们采用高效液相色谱法（HPLC）对102种英国植物花蜜中的游离氨基酸和糖进行测量。通过聚类算法，基于氨基酸的相对比例定义了六种不同的必需氨基酸（EAAs）谱系；随后，我们通过双选择测试检验了蜜蜂（Bombus terrestris）对EAAs谱系及脯氨酸的偏好。我们发现，苯丙氨酸、蛋氨酸和脯氨酸的比例以及必需和非必需氨基酸的总浓度表现出系统发育信号，然而EAAs谱系则没有显示出系统发育信号。蜜蜂并未表现出对六种EAAs花蜜谱系的偏好，然而其中四种EAAs谱系刺激了摄食行为。相反，蜜蜂以浓度依赖性的方式避免了脯氨酸的摄入。我们的数据表明，蜜蜂可能具有对溶液中游离氨基酸进行后消化评估的机制，但不太可能在花蜜相关量级上品味必需氨基酸。我们预测，必需氨基酸能够通过后消化途径增加花蜜对蜜蜂的价值。