Analysis of the different regulation levels and mechanisms of the nectar composition

花蜜是由许多被子植物的花产生，以促进传粉媒介访问介导的杂交。糖占蜜溶质总量的最大份额，但它也含有各种氨基酸、无机离子和其他化合物。单个花蜜的组成和浓度在不同的物种之间有所不同，尽管在较小程度上，在物种内部也有所不同。这些差异可能有多种原因。首先，花蜜是传粉综合征的一部分，其成分可能代表了对传粉者偏好的假设适应。其次，系统或系统发育关系可能会产生影响。第三，气候因素或内部生理过程，包括蜜腺的代谢，可能会影响不同植物物种的成分。前一个项目阶段的结果表明，传粉者对花蜜特定化合物的影响远高于分类关系或环境因素。糖的组成明显受授粉类型的影响，而氨基酸和无机离子的组成分别受分类群和其他因素的影响。本项目的第一个目标是更详细地确定影响花蜜中氨基酸和离子组成和浓度的关键因素。将分析模式科凤梨科的花蜜和蜜腺，并计算系统关系、环境条件、植物形态特征和蜜腺生理的相关性。环境因素也会影响花蜜的组成，初步研究表明，干旱的影响最大。改变的成分反过来又会影响植物与传粉者的相互作用。由于气候变化，干旱可能越来越多地发生，分析它们对花蜜成分的影响变得越来越重要。因此，该项目的第二个目标是提高对不同凤梨属植物在干旱时期花蜜组成变化的了解。花蜜是在蜜腺中产生和分泌的，不同物种的不同代谢也可能导致花蜜成分的差异。因此，该项目的第三个目标是阐明这种对花蜜成分的影响。目前花蜜分泌工作模型的基础主要来自于对植物的研究，而花蜜化合物的代谢和分泌途径尚未完全了解。这尤其适用于单子房或具有特殊授粉类型的物种。花蜜产生的机制在多大程度上是跨物种保守的，这是特别有趣的，也正在这里进行研究。花蜜成分受不同因素的影响。为了了解这一重要生物过程的关键影响和调控机制，有必要进行全面的分析。

Floral nectar is produced by many angiosperm flowers to promote crossing mediated by pollinator visits. Sugars account for the largest share of the total nectar solutes, but it also contains a variety of amino acids, inorganic ions, and other compounds. The composition and concentration of individual nectars varies between species and, albeit to a lesser extent, within species. These differences can have various reasons. Firstly, the floral nectar is part of the pollination syndrome, and its composition may represent putative adaptations to the pollinator’s preferences. Secondly, systematic or phylogenetic relationships may have an impact. Thirdly, climatic factors or internal physiological processes, including the metabolism in the nectaries, may affect the composition in different plant species.Results of the previous project phase show that the pollinator has a much higher influence on specific compounds of the nectar than taxonomic affiliations or environmental factors. Apparently, the sugar composition is clearly influenced by the pollination type, whereas the amino acid and inorganic ion compositions are more influenced by the taxonomic group and several other factors, respectively. The present project’s first aim is to determine the crucial influencing factors on the amino acid and ion composition and concentration in nectars in more detail. Floral nectar and nectaries of the model family Bromeliaceae will be analyzed and correlations with systematic relationships, environmental conditions, morphological plant characteristics, and nectary physiology will be calculated.Environmental factors can also influence the nectar composition and initial studies showed that drought had the largest effect. The changed composition in turn can have an impact on the plant-pollinator interactions. As droughts may increasingly occur due to climate changes, analyses of their influence on nectar composition are of growing importance. Therefore, the project’s second aim is to improve the understanding of changes in nectar composition during drought periods in different bromeliad species.Nectar is produced and secreted in nectaries, the species-specific different metabolisms of which may also cause differences in nectar composition. Therefore, the project’s third aim is to clarify this influence on the nectar composition. The basis for the current working model for nectar secretion are primarily results from studies on eudicots, and the pathways of the metabolism and secretion of nectar compounds are not yet completely understood. This particularly applies to monocots or species with special pollination types. The extent to which the mechanisms of nectar production are conserved across species is of particular interest and is also being researched here. The nectar composition is influenced by different factors. To gain understanding of the key influencing and regulatory mechanisms of this essential biological process, comprehensive analyses are necessary.