The Arabidopsis PHYTOCHROME KINASE SUBSTRATE2 Protein Is a Phototropin Signaling Element That Regulates Leaf Flattening and Leaf Positioning
The Arabidopsis PHYTOCHROME KINASE SUBSTRATE2 Protein Is a Phototropin Signaling Element That Regulates Leaf Flattening and Leaf Positioning
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DOI：
10.1104/pp.109.150441
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发表时间：
2010-03-01
期刊：
影响因子：
7.4
通讯作者：
Fankhauser, Christian
中科院分区：
文献类型：
--
作者：
de Carbonnel, Matthieu;Davis, Phillip;Fankhauser, Christian
在拟南芥（Arabidopsis thaliana）中，蓝光光感受器光致蛋白（phot 1和phot 2）通过控制几个重要的适应性过程来响应环境光变化，从而微调植物的光合作用状态。这些过程包括茎和叶柄的向光性（叶定位），叶片展平，气孔开放和叶绿体运动。植物色素激酶底物（PKS）蛋白家族在拟南芥中包括四个成员（PKS 1-PKS 4）。PKS 1是一种新型的phot 1信号元件，在向光性，因为它与phot 1和重要的信号元件非光性下胚轴3（NPH 3）相互作用，是所需的正常phot 1介导的向光性。在这项研究中，我们更全面地分析了三个PKS成员（PKS 1，PKS 2和PKS 4）的作用。突变体的系统分析表明，PKS 2（和PKS 1在较小程度上）的行为在相同的子集的向光蛋白控制的响应NPH 3，即叶片展平和定位。PKS 1、PKS 2和NPH 3与叶提取物中的phot 1-绿色荧光蛋白和phot 2-绿色荧光蛋白共免疫沉淀。遗传实验中的位置PKS 2的phot 1和phot 2途径控制叶定位和叶展平。NPH 3可以在phot 1和phot 2途径中起作用，PKS 2和NPH 3突变体之间观察到的协同相互作用表明PKS 2和NPH 3在向光素信号传导过程中的互补作用。最后，一些观察结果进一步表明PKS 2可能通过控制生长素的稳态来调节叶片的展平和定位。与以前的研究结果一起，我们的研究结果表明PKS蛋白代表了一个重要的趋光蛋白信号蛋白家族。
In Arabidopsis (Arabidopsis thaliana), the blue light photoreceptor phototropins (phot1 and phot2) fine-tune the photosynthetic status of the plant by controlling several important adaptive processes in response to environmental light variations. These processes include stem and petiole phototropism (leaf positioning), leaf flattening, stomatal opening, and chloroplast movements. The PHYTOCHROME KINASE SUBSTRATE (PKS) protein family comprises four members in Arabidopsis (PKS1-PKS4). PKS1 is a novel phot1 signaling element during phototropism, as it interacts with phot1 and the important signaling element NONPHOTOTROPIC HYPOCOTYL3 (NPH3) and is required for normal phot1-mediated phototropism. In this study, we have analyzed more globally the role of three PKS members (PKS1, PKS2, and PKS4). Systematic analysis of mutants reveals that PKS2 (and to a lesser extent PKS1) act in the same subset of phototropin-controlled responses as NPH3, namely leaf flattening and positioning. PKS1, PKS2, and NPH3 coimmunoprecipitate with both phot1-green fluorescent protein and phot2-green fluorescent protein in leaf extracts. Genetic experiments position PKS2 within phot1 and phot2 pathways controlling leaf positioning and leaf flattening, respectively. NPH3 can act in both phot1 and phot2 pathways, and synergistic interactions observed between pks2 and nph3 mutants suggest complementary roles of PKS2 and NPH3 during phototropin signaling. Finally, several observations further suggest that PKS2 may regulate leaf flattening and positioning by controlling auxin homeostasis. Together with previous findings, our results indicate that the PKS proteins represent an important family of phototropin signaling proteins.