Genome Structures and Halophyte-Specific Gene Expression of the Extremophile Thellungiella parvula in Comparison with Thellungiella salsuginea (Thellungiella halophila) and Arabidopsis
Genome Structures and Halophyte-Specific Gene Expression of the Extremophile Thellungiella parvula in Comparison with Thellungiella salsuginea (Thellungiella halophila) and Arabidopsis
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DOI：
10.1104/pp.110.163923
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发表时间：
2010-11-01
期刊：
影响因子：
7.4
通讯作者：
Bohnert, Hans J.
中科院分区：
文献类型：
--
作者：
Oh, Dong-Ha;Dassanayake, Maheshi;Bohnert, Hans J.
小芥（Thellungiella parvula）是拟南芥（Arabidopsis thaliana）的盐生近亲，其基因组正在使用Roche-454测序进行组装。10-Mb支架的分析揭示了与拟南芥的同线性，具有重组和倒位以及重复序列的不均匀分布。T.将小芥基因组结构和DNA序列与来自拟南芥的正向区和来自盐芥（Thellungiellasalsuggestion）（以前的Thellungiellahalophila）的可公开获得的细菌人工染色体序列进行比较。从一个非生物胁迫敏感的物种和两个宽容的物种的序列的三向比较，揭示了广泛的序列保守性和microcolinearity，但分组Thellungiella物种分别从拟南芥。然而，T. parvula节与它们的T.与盐藻相比，盐藻的重复序列明显减少，导致T.小的在这些基因中，盐过度敏感1（SOS 1）是一种钠/质子反向转运蛋白，是植物耐盐胁迫的重要组成部分。尽管SOS 1编码区在所有三个物种中高度保守，但启动子区仅在两个小蓟属物种之间显示保守性。比较转录本分析显示，与拟南芥相比，在这两种小蓟属物种的基础以及盐诱导的SOS 1表达水平较高。小蓟属物种和其他盐生植物共享在拟南芥中缺失的保守的富含嘧啶的SOS 1 5'非翻译区近端区域。完成了T. parvula预计将突出这种物种极端生活方式的独特遗传因素。
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.