PDF(Pubmed)
Abstract：
Floral nectar contains vital nutrients for pollinators, including sugars, amino acids, proteins, and secondary compounds. As pollinators forage, they inoculate nectar with bacteria and fungi. These microbes can colonize nectaries and alter nectar properties, including volume and chemistry. Abiotic factors, such as temperature, can influence microbial community structure and nectar traits. Considering current climate change conditions, studying the effects of increased temperature on ecosystem processes like pollination is ever more important. In a manipulative field experiment, we used a passive-heating technique to increase the ambient temperature of a California native plant, Penstemon heterophyllus, to test the hypothesis that temperatures elevated an average of 0.5°C will affect nectar properties and nectar-inhabiting microbial communities. We found that passive-heat treatment did not affect nectar properties or microbial communities. Penstemon heterophyllus fruit set also was not affected by passive-heat treatments, and neither was capsule mass, however plants subjected to heat treatments produced significantly more seeds than control. Although we conducted pollinator surveys, no pollinators were recorded for the duration of our experiment. A naturally occurring extreme temperature event did, however, have large effects on nectar sugars and nectar-inhabiting microbial communities. The initially dominant Lactobacillus sp. was replaced by Sediminibacterium, while Mesorhizobium, and Acinetobacter persisted suggesting that extreme temperatures can interrupt nectar microbiome community assembly. Our study indicates that the quality and attractiveness of nectar under climate change conditions could have implications on plant-pollinator interactions.
摘要：
花蜜含有传粉者的重要营养素，包括糖,氨基酸,蛋白质，和次要化合物。当传粉者觅食时，他们用细菌和真菌接种花蜜。这些微生物可以定殖蜜腺并改变蜜腺的特性，包括体积和化学。非生物因子，如温度，可以影响微生物群落结构和花蜜性状。考虑到当前的气候变化条件，研究温度升高对授粉等生态系统过程的影响越来越重要。在一个操纵性的现场实验中，我们使用被动加热技术来提高加州本地植物的环境温度，仙人掌，为了检验以下假设：温度平均升高0.5°C会影响花蜜的特性和花蜜居住的微生物群落。我们发现被动热处理不会影响花蜜的性质或微生物群落。Penstemonheterophylus果也不受被动热处理的影响，也不是胶囊质量，然而，经过热处理的植物产生的种子明显多于对照。虽然我们进行了传粉者调查，在我们的实验期间没有传粉者被记录.自然发生的极端温度事件确实如此，然而,对花蜜糖和花蜜微生物群落有很大影响。最初占优势的乳杆菌属。被塞迪内细菌所取代，而根瘤菌，不动杆菌坚持认为极端温度可以中断花蜜微生物群落的组装。我们的研究表明，在气候变化条件下，花蜜的质量和吸引力可能会对植物-传粉者的相互作用产生影响。
