A chromosome-level genome assembly of Plantago ovata

Abstract

Plantago ovata is cultivated for production of its seed husk (psyllium). When wet, the husk transforms into a mucilage with properties suitable for pharmaceutical industries, utilised in supplements for controlling blood cholesterol levels, and food industries for making gluten-free products. There has been limited success in improving husk quantity and quality through breeding approaches, partly due to the lack of a reference genome. Here we constructed the first chromosome-scale reference assembly of P. ovata using a combination of 5.98 million PacBio and 636.5 million Hi-C reads. We also used corrected PacBio reads to estimate genome size and transcripts to generate gene models. The final assembly covers ~ 500 Mb with 99.3% gene set completeness. A total of 97% of the sequences are anchored to four chromosomes with an N50 of ~ 128.87 Mb. The P. ovata genome contains 61.90% repeats, where 40.04% are long terminal repeats. We identified 41,820 protein-coding genes, 411 non-coding RNAs, 108 ribosomal RNAs, and 1295 transfer RNAs. This genome will provide a resource for plant breeding programs to, for example, reduce agronomic constraints such as seed shattering, increase psyllium yield and quality, and overcome crop disease susceptibility.

A chromosome-level reference genome of an aromatic medicinal plant Adenosma buchneroides

“…Up to now, many efforts on the regulation mechanism of aromatic component biosynthesis has been made in the genus Thymus (Lamiaceae). Though most recently, several pseudo-chromosome level genomes of Plantaginaceae were published [9][10][11] . The molecular basis and evolution of those components biosynthesis in A. buchneroides (Plantaginaceae) are rarely reported due to the lack of a high-quality reference genome.…”