title: The first draft genome of the aquatic model plant Lemna minor opens the route for future stress physiology research and biotechnological applications.
abstract: BACKGROUND
  Freshwater duckweed, comprising the smallest, fastest growing and simplest macrophytes has various applications in agriculture, phytoremediation and energy production. Lemna minor, the so-called common duckweed, is a model system of these aquatic plants for ecotoxicological bioassays, genetic transformation tools and industrial applications. Given the ecotoxic relevance and high potential for biomass production, whole-genome information of this cosmopolitan duckweed is needed.
  
  
  RESULTS
  The 472 Mbp assembly of the L. minor genome (2n = 40; estimated 481 Mbp; 98.1 %) contains 22,382 protein-coding genes and 61.5 % repetitive sequences. The repeat content explains 94.5 % of the genome size difference in comparison with the greater duckweed, Spirodela polyrhiza (2n = 40; 158 Mbp; 19,623 protein-coding genes; and 15.79 % repetitive sequences). Comparison of proteins from other monocot plants, protein ortholog identification, OrthoMCL, suggests 1356 duckweed-specific groups (3367 proteins, 15.0 % total L. minor proteins) and 795 Lemna-specific groups (2897 proteins, 12.9 % total L. minor proteins). Interestingly, proteins involved in biosynthetic processes in response to various stimuli and hydrolase activities are enriched in the Lemna proteome in comparison with the Spirodela proteome.
  
  
  CONCLUSIONS
  The genome sequence and annotation of L. minor protein-coding genes provide new insights in biological understanding and biomass production applications of Lemna species.
authors.affiliation: Biosphere Impact Studies, SCK•CEN, Boeretang 200, 2400 Mol, Belgium ; Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
authors.forename: Arne
authors.initials: A
authors.lastname: Van Hoeck
authors.affiliation: Biosphere Impact Studies, SCK•CEN, Boeretang 200, 2400 Mol, Belgium ; Centre for Environmental Research, University of Hasselt, Universiteitslaan 1, 3590 Diepenbeek, Belgium.
authors.forename: Nele
authors.initials: N
authors.lastname: Horemans
authors.affiliation: Microbiology, SCK•CEN, Boeretang 200, 2400 Mol, Belgium.
authors.forename: Pieter
authors.initials: P
authors.lastname: Monsieurs
authors.affiliation: Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Corrensstrasse 3, 06466 Stadt Seeland, Germany.
authors.forename: Hieu Xuan
authors.initials: HX
authors.lastname: Cao
authors.affiliation: Biosphere Impact Studies, SCK•CEN, Boeretang 200, 2400 Mol, Belgium.
authors.forename: Hildegarde
authors.initials: H
authors.lastname: Vandenhove
authors.affiliation: Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
authors.forename: Ronny
authors.initials: R
authors.lastname: Blust
keywords: Biomass production; Duckweed; Ecotoxicology; Lemna minor; Toxicogenomics; Whole-genome sequencing