RPT2 is a signal transducer involved in phototropic response and stomatal opening by association with phototropin 1 in Arabidopsis thaliana
RPT2 is a signal transducer involved in phototropic response and stomatal opening by association with phototropin 1 in Arabidopsis thaliana
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DOI：
10.1105/tpc.019901
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发表时间：
2004-04-01
期刊：
影响因子：
11.6
通讯作者：
Sakai, T
中科院分区：
文献类型：
--
作者：
Inada, S;Ohgishi, M;Sakai, T
Phototropin 1（phot1）和phot2是蓝光受体激酶，在蓝光诱导的拟南芥下胚轴向光性、叶绿体移位和气孔开放中起作用。先前的研究已经表明，蛋白RPT 2（用于根向光性2）和NPH 3（用于非向光性下胚轴3）在向光性蛋白下游传递信号以诱导向光性反应。然而，RPT 2和NPH 3参与气孔开放和叶绿体迁移介导的光1和光2是未知的。RPT 2突变体和一系列双突变体的遗传分析表明，RPT 2参与光1诱导的向光性反应和气孔开放，但不参与叶绿体搬迁或光2诱导的运动。生化分析表明，RPT 2纯化的粗微粒体部分，以及phot1和NPH 3，RPT 2使一个复杂的phot1在体内。另一方面，NPH 3不是气孔开放或叶绿体迁移所必需的。因此，这些结果表明，phot1和phot2选择不同的信号转导诱导三种反应：向光反应的下胚轴，气孔开放，叶绿体搬迁。
Phototropin 1 (phot1) and phot2, which are blue light receptor kinases, function in blue light-induced hypocotyl phototropism, chloroplast relocation, and stomatal opening in Arabidopsis (Arabidopsis thaliana). Previous studies have shown that the proteins RPT2 (for ROOT PHOTOTROPISM2) and NPH3 (for NONPHOTOTROPIC HYPOCOTYL3) transduce signals downstream of phototropins to induce the phototropic response. However, the involvement of RPT2 and NPH3 in stomatal opening and in chloroplast relocation mediated by phot1 and phot2 was unknown. Genetic analysis of the rpt2 mutant and of a series of double mutants indicates that RPT2 is involved in the phot1-induced phototropic response and stomatal opening but not in chloroplast relocation or phot2-induced movements. Biochemical analyses indicate that RPT2 is purified in the crude microsomal fraction, as well as phot1 and NPH3, and that RPT2 makes a complex with phot1 in vivo. On the other hand, NPH3 is not necessary for stomatal opening or chloroplast relocation. Thus, these results suggest that phot1 and phot2 choose different signal transducers to induce three responses: phototropic response of hypocotyl, stomatal opening, and chloroplast relocation.