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The analysis of environmental DNA (eDNA) is a powerful and non-invasive method for monitoring the presence of species in ecosystems. However, ecologists and laboratory staff can find it challenging to use eDNA analysis software effectively due to the unfamiliar command-line interfaces used by many of these packages. Therefore, we developed the eDNA-container app, a free and open-source software package that provides a simple user-friendly interface for eDNA analysis. The application is based on the popular QIIME2 library and is distributed as a Docker image. The use of Docker makes it compatible with a wide range of operating systems and facilitates the reproducible analysis of data across different laboratories. The application includes a point-and-click user interface for selecting sequencing files, configuring parameters, and accessing the results. Key pipeline outputs, such as sequence quality plots, denoising, and ASV generation statistics, are automatically included in a PDF report. This open-source and freely available analysis package should be a valuable tool for scientists using eDNA in biodiversity and biosecurity applications.

Bacteria use quorum sensing signaling for cell-to-cell communication, which is also important for their interactions with plant hosts. Quorum sensing via N-acyl-homoserine lactones (AHLs) is important for successful symbioses between legumes and nitrogen-fixing rhizobia. Previous studies have shown that plant hosts can recognize and respond to AHLs. Here, we tested whether the response of the model legume Medicago truncatula to AHLs from its symbiont and other bacteria could be modulated by the abundance and composition of plant-associated microbial communities. Temporary antibiotic treatment of the seeds removed the majority of bacterial taxa associated with M. truncatula roots and significantly altered the effect of AHLs on nodule numbers, but lateral root density, biomass, and root length responses were much less affected. The AHL 3-oxo-C14-HSL (homoserine lactone) specifically increased nodule numbers but only after the treatment of seeds with antibiotics. This increase was associated with increased expression of the early nodulation genes RIP1 and ENOD11 at 24 h after infection. A 454 pyrosequencing analysis of the plant-associated bacteria showed that antibiotic treatment had the biggest effect on bacterial community composition. However, we also found distinct effects of 3-oxo-C14-HSL on the abundance of specific bacterial taxa. Our results revealed a complex interaction between plants and their associated microbiome that could modify plant responses to AHLs.