Metagenomic analysis of historical herbarium specimens reveals a postmortem microbial community.

摘要: Advances in DNA extraction and next-generation sequencing have made a vast number of historical herbarium specimens available for genomic investigation. These contain not only information from the individual plants themselves, but also associated microorganisms such as bacteria fungi. may colonized living plant (e.g., pathogens or host-associated commensal taxa) result postmortem colonization that include decomposition processes contamination during sample handling. Here we characterize metagenomic profile shotgun data two widespread species (Ambrosiaartemisiifolia Arabidopsis thaliana) collected up to 180 years ago. We used blast searching combination with megan were able infer community even oldest sample. Through comparison contemporary collections, identify three microbial are nearly exclusive specimens, including fungus Alternaria alternata, which can comprise 7% total reads. This probably colonizes preparation mounting storage. By removing probable contaminating taxa, observe temporal shift composition invasive weed Am. artemisiifolia. Our findings demonstrate it is generally possible use analyses, results should be treated caution, some identified contaminants rather than representing natural host plant.