English Seminars
The Genome of an Extremophile, Thellungiella parvula (Brassicaceae)
| Title | The Genome of an Extremophile, Thellungiella parvula (Brassicaceae) |
| Lecturer | Prof. Hans J. Bohnert (University of Illinois at Urbana-Champaign) |
| Language | English |
| Date&Time | 04/11/2011 (Mon) 16：30～17：45 |
| Venue | L１2会議室 |
| Detail | The genome of Thellungiella parvula, a halophytic relative of Arabidopsis
(Arabidopsis thaliana), is being assembled using Roche-454 sequencing.
Analyses of a 10-Mb scaffold revealed synteny with Arabidopsis, with
recombination and inversion and an uneven distribution of repeat
sequences. T. parvula genome structure and DNA sequences were compared
with orthologous regions from Arabidopsis and publicly available
bacterial artificial chromosome sequences from Thellungiella salsuginea
(previously Thellungiella halophila). The three-way comparison of
sequences, from one abiotic stress-sensitive species and two tolerant
species, revealed extensive sequence conservation and microcolinearity,
but grouping Thellungiella species separately from Arabidopsis. However,
the T. parvula segments are distinguished from their T. salsuginea
counterparts by a pronounced paucity of repeat sequences, resulting in a
30% shorter DNA segment with essentially the same gene content in T.
parvula. Among the genes is SALT OVERLY SENSITIVE1 (SOS1), a
sodium/proton antiporter, which represents an essential component of
plant salinity stress tolerance. Although the SOS1 coding region is
highly conserved among all three species, the promoter regions show
conservation only between the two Thellungiella species. Comparative
transcript analyses revealed higher levels of basal as well as
salt-induced SOS1 expression in both Thellungiella species as compared
with Arabidopsis. The Thellungiella species and other halophytes share
conserved pyrimidine-rich 5' untranslated region proximal regions of
SOS1 that are missing in Arabidopsis. Completion of the genome structure
of T. parvula is expected to highlight distinctive genetic elements
underlying the extremophile lifestyle of this species. From Plant Physiol. 154, 1040-1052 (2010) |
| Contact | 分化・形態形成学 横田 明穂 (yokota@bs.naist.jp) |