Next-generation sequencing reveals the impact of repetitive DNA across phylogenetically closely related genomes of Orobanchaceae.
We used next-generation sequencing to characterize the genomes of nine species of Orobanchaceae of known phylogenetic relationships, different life forms, and including a polyploid species. The study species are the autotrophic, nonparasitic Lindenbergia philippensis, the hemiparasitic Schwalbea americana, and seven nonphotosynthetic parasitic species of Orobanche (Orobanche crenata, Orobanche cumana, Orobanche gracilis (tetraploid), and Orobanche pancicii) and Phelipanche (Phelipanche lavandulacea, Phelipanche purpurea, and Phelipanche ramosa). Ty3/Gypsy elements comprise 1.93%-28.34% of the nine genomes and Ty1/Copia elements comprise 8.09%-22.83%. When compared with L. philippensis and S. americana, the nonphotosynthetic species contain higher proportions of repetitive DNA sequences, perhaps reflecting relaxed selection on genome size in parasitic organisms. Among the parasitic species, those in the genus Orobanche have smaller genomes but higher proportions of repetitive DNA than those in Phelipanche, mostly due to a diversification of repeats and an accumulation of Ty3/Gypsy elements. Genome downsizing in the tetraploid O. gracilis probably led to sequence loss across most repeat types.
Systematic Botany and Mycology, University of Munich (LMU), Munich, Germany. piednoel@closun.snv.jussieu.fr
Mathieu
M
Piednoël
Andre J
AJ
Aberer
Gerald M
GM
Schneeweiss
Jiri
J
Macas
Petr
P
Novak
Heidrun
H
Gundlach
Eva M
EM
Temsch
Susanne S
SS
Renner
D016000:Cluster Analysis; D018744:DNA, Plant / Q000235:genetics*; D059646:Genome Size / Q000235:genetics; D018745:Genome, Plant / Q000235:genetics*; D059014:High-Throughput Nucleotide Sequencing; D008969:Molecular Sequence Data; D031670:Orobanchaceae / Q000235:genetics*; D010802:Phylogeny; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*; D017422:Sequence Analysis, DNA / Q000379:methods*; D013045:Species Specificity
D018744:DNA, Plant