Biotic and abiotic effects on pollen production and allergenicity of birch and related health impacts

尽管更高的温度经常被发现会增加花粉的产生和过敏性，但几项研究报告称，在更温暖的条件下，花粉数量和过敏原含量会减少。到目前为止，人们对可能改变这些花粉特征的其他生物和非生物因素知之甚少。花粉对人类的影响可能存在显着差异，这取决于花粉的总体产量和致敏潜力。在这项研究中，我们关注北欧、中欧和东欧最重要的致敏树种：桦树(Betula spp.)主要的新颖性是分析了欧洲国际物候园中不存在自然环境遗传差异的克隆桦树个体对花粉的生物和非生物影响。此外，在巴伐利亚州的一个种子种植园中研究克隆个体的桦树花粉，可以保证排除遗传多样性以及树龄和小气候。我们进一步将重点放在阿尔卑斯山北部海拔梯度上的白桦树上，那里提供了各种气候条件和巨大的遗传和物种多样性。除了调查影响花粉产生和过敏原含量的非生物因素(如气温、相对湿度、空气污染物)外，我们还重点研究了生物因素，如病毒感染(樱桃卷叶病毒)或与花粉相关的微生物群，以及通过皮肤点刺试验研究花粉变应原的体内相关性。通过我们的研究获得更多的知识，可以更详细地预测未来气候变化条件下的变化。景观生态学、植物医学和环境医学的科学家之间的跨学科合作将回答生物和非生物因素如何影响花粉产生和过敏性，最终影响患者的过敏反应。

Although higher temperatures were often found to increase pollen production and allergenicity, several studies reported decreased quantities of pollen and allergen content under warmer conditions. Up to now, little is known about additional biotic and abiotic factors that might alter these pollen characteristics. There might exist a remarkable difference in the impact of pollen on human beings depending on the overall production and allergenic potential of pollen. In this study, we focus on the most important allergenic tree species in northern, central, and eastern Europe: birch (Betula spp.). The major novelty is the analysis of biotic and abiotic impacts on pollen of cloned birch individuals free from genetic differences in their natural environment across International Phenological Gardens in Europe. In addition, studying birch pollen of cloned individuals in a seed plantation in Bavaria guarantees the exclusion of genetic diversity as well as tree age and microclimate. We further focus on birch trees along an altitudinal gradient in the northern Alps that offers a variety of climatic conditions and a great genetic and species diversity. Besides the investigation of abiotic factors (e.g., air temperature, relative humidity, air pollutants) influencing pollen production and allergen content, we also focus on biotic factors such as virus infections (Cherry leaf roll virus) or the pollen-associated microbiome and the in vivo relevance of the pollen’s allergenicity using skin prick tests. A greater knowledge gained by our study allows the prediction of future alterations under climate change conditions in more detail. An interdisciplinary collaboration between scientists of landscape ecology, phytomedicine and environmental medicine shall answer how biotic and abiotic factors impact pollen production and allergenicity and finally the allergic reactions in patients.