Russell Kaleigh A, McFrederick Quinn S
Department of Entomology, University of California, Riverside, Riverside, CA, United States.
Front Microbiol. 2022 Aug 25;13:931291. doi: 10.3389/fmicb.2022.931291. eCollection 2022.
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, , 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. 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 sp. was replaced by while and 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.
花蜜含有对传粉者至关重要的营养物质，包括糖类、氨基酸、蛋白质和次生化合物。传粉者觅食时，会将细菌和真菌接种到花蜜中。这些微生物可以在蜜腺中定殖并改变花蜜特性，包括体积和化学成分。非生物因素，如温度，会影响微生物群落结构和花蜜特征。考虑到当前的气候变化状况，研究温度升高对授粉等生态系统过程的影响变得更加重要。在一项可控的田间实验中，我们使用被动加热技术提高了加利福尼亚本土植物的环境温度，以检验平均升高0.5°C的温度会影响花蜜特性和花蜜中微生物群落这一假设。我们发现被动加热处理并未影响花蜜特性或微生物群落。坐果率也不受被动加热处理的影响，蒴果质量同样如此，然而，接受热处理的植物产生的种子明显比对照多。尽管我们进行了传粉者调查，但在实验期间未记录到传粉者。然而，一次自然发生的极端温度事件对花蜜糖分和花蜜中微生物群落产生了很大影响。最初占主导地位的 物种被 取代，而 和 持续存在，这表明极端温度会中断花蜜微生物群落的组装。我们的研究表明，气候变化条件下花蜜的质量和吸引力可能会对植物 - 传粉者相互作用产生影响。
