Novel auxin signaling components and pathways.

项目摘要 植物激素生长素几乎参与植物生长和发育的所有方面。来 多年来，我们和其他人已经证明，生长素的作用是刺激一个家庭的退化， 称为Aux/IAA蛋白的转录抑制因子，通过泛素蛋白连接酶的作用 SCFTIR1/AFB。虽然这一基本途径已经建立，但我们对生长素如何调节 植物生长发育。引人注目的是，生长素调控的基因在细胞类型之间存在显着差异， 器官，与激素的不同作用相一致。这种特异性的基础尚不清楚。同样地， Aux/IAA和ARF蛋白的活性特征很差， 还没有定义介导各种生长素调节的生长过程的GRN。最后，我们对 关于生长素信号是如何与其他环境和遗传信号途径相结合的。 最近，我们发现生长素共受体TIR 1/AFB家族的一个成员AFB 1，具有一个关键的 在根中的非基因组快速生长素反应中的作用。这是一个令人惊讶的结果，因为TIR 1/AFB 已知蛋白质在转录调节中起作用。我们还证明，AFB 1是高度 在细胞质中富集，并提出正是这种特征导致了其在快速生长中的专门作用。 反应 在本提案中，我们请求资金购买Agilent Technologies Synergy H1 Hybrid Multi-Mode 酶标仪。该仪器非常适合高通量测定植物生长素的反应， 立碗藓和荧光素酶水平的测量。

Project Summary The plant hormone auxin is involved in virtually all aspects of plant growth and development. Over the years we and others have demonstrated that auxin acts by stimulating the degradation of a family of transcriptional repressors called the Aux/IAA proteins, through the action of the ubiquitin protein ligase SCFTIR1/AFB. Although this basic pathway is well established, we still know very little about how auxin regulates plant growth and development. Strikingly, auxin-regulated genes differ dramatically between cell types and organs, consistent with the diverse roles of the hormone. The basis for this specificity is unknown. Similarly, the activities of the Aux/IAA and ARF proteins are poorly characterized and the gene regulatory networks (GRNs) that mediate various auxin-regulated growth processes have not been defined. Finally, we know little about how auxin signaling is integrated with other environmental and genetic signaling pathways. Recently we discovered that one member of the TIR1/AFB family of auxin co-receptors, AFB1, has a key role in a non-genomic rapid auxin response in the root. This was a surprising result because the TIR1/AFB proteins are known to function in transcriptional regulation. We also demonstrated that AFB1 is highly enriched in the cytoplasm and propose that it is this feature that leads to its specialized role in the rapid response. In this proposal, we request funds to purchase a Agilent Technologies Synergy H1 Hybrid Multi-Mode Microplate Reader. This instrument is ideally suited to high through-put assays of auxin response in Physcomitrellum and measurements of Luciferase levels.