Third release of the plant rDNA database with updated content and information on telomere composition and sequenced plant genomes

Abstract

Here we present the third release of the plant rDNA database (March 2017), an open access online resource with information on numbers, locations and structure of 5S and 18S-5.8S-26S (35S) ribosomal DNA (rDNA) (www.plantrdnadatabase.com). Data are now available for 2148 species (3783 entries), extracted from 785 papers published until the end of 2016. This means an expansion of 33.5% in terms of new species and 13% in new publications consulted. We appreciate an increased interest on rDNA loci research in recent years, since 10.78% of all data available were published only in 2016. The database has been expanded to include information on telomere composition and on species whose genome has been fully sequenced up to date. Telomere sequence is only known with certainty for 9.60% of species in the database and for 36.79% at the genus level, indicating, potentially, that the consensus plant telomere (Arabidopsis-type) might not be as extended as previously thought. We have also introduced the taxonomic category order as an additional option for data browsing. Similarly, we have included a new category to indicate the hybrid status of taxa. In addition, we upgraded and/or proofread tabs and links and slightly modified the website for a more dynamic appearance. This manuscript provides a synopsis of these changes and developments.