Physcomitrella patens Auxin-Resistant Mutants Affect Conserved Elements of an Auxin-Signaling Pathway
Physcomitrella patens Auxin-Resistant Mutants Affect Conserved Elements of an Auxin-Signaling Pathway
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DOI：
10.1016/j.cub.2010.08.050
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发表时间：
2010-11-09
期刊：
影响因子：
9.2
通讯作者：
Estelle, Mark
中科院分区：
文献类型：
--
作者：
Prigge, Michael J.;Lavy, Meirav;Estelle, Mark
生长素调节开花植物生长和发育的大部分方面，包括在近5亿年前从类似britecte的祖先分化后在维管植物谱系内进化的关键发育创新[1-3]。最近在拟南芥中的研究表明，生长素通过直接结合SCF（TIR 1）泛素连接酶的TIR 1亚基而起作用;这种结合导致Aux/IAA转录阻遏物的降解和生长素响应基因的去阻遏[4-9]。然而，对生长素在其他植物中的作用机制知之甚少。为了表征生长素信号在nonflowering植物，我们利用了遗传上易处理的苔藓小立碗藓。我们使用了候选基因的方法，以显示以前确定的生长素抗性突变体的P. patens港口Aux/IAA基因突变。此外，我们表明，苔藓Aux/IAA蛋白与拟南芥TIR 1苔藓同系物称为PpAFB和PpAFB水平的减少导致类似的生长素抗性突变体的表型相互作用。我们的研究结果表明，生长素感知的分子机制是保守的陆地植物，尽管生长素在不同的植物谱系中发挥的作用存在巨大差异。
Auxin regulates most aspects of flowering-plant growth and development, including key developmental innovations that evolved within the vascular plant lineage after diverging from a bryophyte-like ancestor nearly 500 million years ago [1-3]. Recent studies in Arabidopsis indicate that auxin acts by directly binding the TIR1 subunit of the SCF(TIR1) ubiquitin ligase; this binding results in degradation of the Aux/IAA transcriptional repressors and de-repression of auxin-responsive genes [4-9]. Little is known, however, about the mechanism of auxin action in other plants. To characterize auxin signaling in a nonflowering plant, we utilized the genetically tractable moss Physcomitrella patens. We used a candidate-gene approach to show that previously identified auxin-resistant mutants of P. patens harbor mutations in Aux/IAA genes. Furthermore, we show that the moss Aux/IAA proteins interact with Arabidopsis TIR1 moss homologs called PpAFB and that a reduction in PpAFB levels results in a phenotype similar to that of the auxin-resistant mutants. Our results indicate that the molecular mechanism of auxin perception is conserved in land plants despite vast differences in the role auxin plays in different plant lineages.