Despite the low availability of nitrogen (N), the highly productive macrophyte Hydrilla verticillata (L.) is a successful invader of the littoral zones at lake Atitlán, Guatemala, with profound implications for lake ecology. To help answer the question of how Hydrilla , accompanied by the filamentous green alga Cladophora Kützing (Ulvophyceae), sustains fast growth under conditions of N scarcity, we studied the composition and potential biogeochemical function of the associated microbiomes. We combined results from next generation sequencing of associated bacterial and fungal assemblages with traditional microscopy-based taxonomical evaluation of algae and cyanobacteria. We focused on the presence of specific N 2 -fixing genera and their relative importance. Data on community composition are complemented with measurements of diazotrophic activity. The results expand our knowledge of the ecophysiology of these algae-plant-microbe consortia and suggest that several levels of biological complexity should be considered to fully understand aquatic plant ecology and the process of macrophyte invasions.

中文翻译：

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复杂的叶圈微生物组有助于在氮缺乏的条件下建立入侵性大型植物黑藻（Hydrilla verticillata）

尽管氮（N）的利用率很低，但高产的大型植物绿藻（Hydrilla verticillata）（L.）成功入侵了危地马拉阿提特兰湖沿岸带，对湖泊生态学产生了深远的影响。为了帮助回答Hydrilla与丝状绿藻CladophoraKützing（Ulvophyceae）在氮缺乏的条件下如何维持快速生长的问题，我们研究了相关微生物组的组成和潜在的生物地球化学功能。我们将下一代相关细菌和真菌组合的测序结果与基于藻类和蓝细菌的传统基于显微镜的生物分类学评估相结合。我们专注于特定N 2固定属的存在及其相对重要性。有关群落组成的数据辅以重氮营养活性的测定。