Opportunities for diversified usage of metabarcoding data for fungal biogeography through increased metadata quality

The widely adopted use of metabarcoding techniques and the ability to sequence microbial communities directly from environmental samples have advanced the field of fungal ecol-ogy. The growth of publicly available big data offers opportunities for collating data from different sources to explore biogeographical and macroecological patterns of fungal groups over large spatial scales. This requires reliable and high-quality metadata associated with the raw sequencing data. We assessed the accuracy of submitted metadata linked to terrestrial plant-associated fungal genetic marker sequences, extracted from NCBI's Bio-Project web-portal. The amount of correctly captured, missing, and incorrectly supplied metadata was determined. The quality of submitter-defined metadata was of a variable quality, with some adhering to metadata standards, and others not capturing metadata for certain attributes or, when metadata was captured, duplicating metadata across sam-ples, or only partially meeting metadata requirements. This ultimately limits the ability to find, and subsequently re-use, sequence data. The rapid accumulation of metabarcoding data and the ability to directly compare samples taken from different studies holds oppor-tunities for gaining a deeper understanding of fungal biogeographical patterns and their drivers. Standardised vocabularies for metadata attributes during submission to public re-positories like NCBI's Sequence Read Archive, coupled with adequate incentives for the data providers, would facilitate the Findability, Accessibility, Interoperability, and Reus-ability (FAIR) data principles and ultimately enable metabarcoding sequence data to be readily utilized to perform large scale global biogeographical studies on the kingdom Fungi. & COPY; 2023 The Authors. Published by Elsevier Ltd on behalf of British Mycological Society. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/ 4.0/).

Automated summary

The use of metabarcoding techniques and sequencing microbial communities directly from environmental samples have advanced fungal ecology. However, the accuracy of submitted metadata associated with fungal genetic marker sequences needs improvement. The quality of submitter-defined metadata varies, with some adhering to standards and others not meeting requirements, limiting the ability to find and reuse sequence data.