Analysis of the Arabidopsis histidine kinase ATHK1 reveals a connection between vegetative osmotic stress sensing and seed maturation
Analysis of the Arabidopsis histidine kinase ATHK1 reveals a connection between vegetative osmotic stress sensing and seed maturation
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DOI：
10.1105/tpc.107.055871
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发表时间：
2008-04-01
期刊：
影响因子：
11.6
通讯作者：
Sussman, Michael R.
中科院分区：
文献类型：
--
作者：
Wohlbach, Dana J.;Quirino, Betania F.;Sussman, Michael R.
为了科普水分胁迫，植物必须能够有效地感知、响应和适应水资源的变化。拟南芥质膜His激酶ATHK1被认为是一种能检测水分胁迫并启动下游反应的光合传感器。在这里，我们提供了直接的遗传证据表明，ATHK1不仅参与了植物生长早期营养阶段的水分胁迫反应，而且在种子形成过程中的干燥过程的调节中发挥了独特的作用。为了更全面地识别受ATHK1介导的水胁迫反应影响的下游途径中涉及的基因，我们创建了一个大规模的表达数据汇总，称为AtMegaCluster。在AtMegaCluster中，使用分层聚类技术将athk1突变体的全基因组表达水平与在各种条件下生长的拟南芥组织的公开数据集中报道的表达水平进行比较。这些实验表明，ATHK1与几种拟南芥反应调节因子以及两种含有新序列的蛋白质一起进行共转录调节。由于ATHK1的过度表达增加了对水分胁迫的耐受性，我们的观察结果表明，通过受体介导的增加感知水分状态，而不是通过下游转录因子或特定渗透调节因子的基因工程变化，增加抗旱性的一个新的自上而下的途径。
To cope with water stress, plants must be able to effectively sense, respond to, and adapt to changes in water availability. The Arabidopsis thaliana plasma membrane His kinase ATHK1 has been suggested to act as an osmosensor that detects water stress and initiates downstream responses. Here, we provide direct genetic evidence that ATHK1 not only is involved in the water stress response during early vegetative stages of plant growth but also plays a unique role in the regulation of desiccation processes during seed formation. To more comprehensively identify genes involved in the downstream pathways affected by the ATHK1-mediated response to water stress, we created a large-scale summary of expression data, termed the AtMegaCluster. In the AtMegaCluster, hierarchical clustering techniques were used to compare whole-genome expression levels in athk1 mutants with the expression levels reported in publicly available data sets of Arabidopsis tissues grown under a wide variety of conditions. These experiments revealed that ATHK1 is cotranscriptionally regulated with several Arabidopsis response regulators, together with two proteins containing novel sequences. Since overexpression of ATHK1 results in increased water stress tolerance, our observations suggest a new top-down route to increasing drought resistance via receptor-mediated increases in sensing water status, rather than through genetically engineered changes in downstream transcription factors or specific osmolytes.