The Arabidopsis TETRATRICOPEPTIDE THIOREDOXIN-LIKE Gene Family Is Required for Osmotic Stress Tolerance and Male Sporogenesis
The Arabidopsis TETRATRICOPEPTIDE THIOREDOXIN-LIKE Gene Family Is Required for Osmotic Stress Tolerance and Male Sporogenesis
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DOI：
10.1104/pp.111.188920
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发表时间：
2012-03-01
期刊：
影响因子：
7.4
通讯作者：
Botella, Miguel A.
中科院分区：
文献类型：
--
作者：
Lakhssassi, Naoufal;Doblas, Veronica G.;Botella, Miguel A.
四三肽硫氧还蛋白样 (TTL) 蛋白的特征是在保守位置存在六个四三肽重复序列，以及一个被称为硫氧还蛋白样结构域的羧基末端区域，与硫氧还蛋白具有同源性。在拟南芥（Arabidopsis thaliana）中，TTL基因家族由四个成员组成，其中创始成员TTL1是渗透胁迫耐受所必需的。基因组测序分析表明，TTL 基因是陆地植物特有的。在本研究中，我们使用数据挖掘和启动子-报告基因 β-葡萄糖醛酸酶融合来报告拟南芥 TTL 基因的表达谱。我们的结果表明，TTL1、TTL3 和 TTL4 在正常生长条件下表现出普遍表达，但在响应渗透压和 NaCl 胁迫时表现出差异表达模式。 TTL2 显示出一种非常不同的表达模式，是花粉粒特有的。与表达数据一致，ttl1、ttl3和ttl4突变体在渗透胁迫下表现出根系生长减少，对双突变体和三突变体的分析表明，TTL1、TTL3和TTL4在非生物胁迫耐受性中具有部分重叠但特定的功能，而TTL2参与雄性配子体传递。
TETRATRICOPEPTIDE THIOREDOXIN-LIKE (TTL) proteins are characterized by the presence of six tetratricopeptide repeats in conserved positions and a carboxyl-terminal region known as the thioredoxin-like domain with homology to thioredoxins. In Arabidopsis (Arabidopsis thaliana), the TTL gene family is composed by four members, and the founder member, TTL1, is required for osmotic stress tolerance. Analysis of sequenced genomes indicates that TTL genes are specific to land plants. In this study, we report the expression profiles of Arabidopsis TTL genes using data mining and promoter-reporter beta-glucuronidase fusions. Our results show that TTL1, TTL3, and TTL4 display ubiquitous expression in normal growing conditions but differential expression patterns in response to osmotic and NaCl stresses. TTL2 shows a very different expression pattern, being specific to pollen grains. Consistent with the expression data, ttl1, ttl3, and ttl4 mutants show reduced root growth under osmotic stress, and the analysis of double and triple mutants indicates that TTL1, TTL3, and TTL4 have partially overlapping yet specific functions in abiotic stress tolerance while TTL2 is involved in male gametophytic transmission.