Using auxin to understand context-dependent hormone response

标题：使用生长素了解上下文相关的激素反应 项目摘要 细胞不断地整合一套内在和外在的信息来协调他们的 活动。细胞感知到的一系列刺激--上下文--可以极大地改变 对后续刺激的反应。植物激素生长素提供了一个有趣的例子 这种上下文相关的反应：生长素调节各种现象，从细胞扩张到 说明植物生命各方面的细胞命运。同样的荷尔蒙是如何引起这样的 不同背景下的不同反应是未知的。在这里，我建议开展工作，以发现 依赖于环境的生长素反应所需的遗传因素。拟南芥幼苗 柳杉在光照下生长时对外源生长素的反应与在光照下生长时相反 夜幕降临。我假设生长素在光明和黑暗中触发不同的遗传途径。 使用拟南芥作为模型，我将首先通过执行突变筛选来验证这一假设 将分离上下文相关和上下文无关生长素所需的新因素 发信号。我随后将分析生长素的DNA结合图景如何响应 因子(ARF)转录效应器在光照和黑暗生长的下胚轴中进行比较。如果ARF 结合因环境而有很大不同，我将测试染色质的差异 可访问性是这种变化的基础。如果ARF DNA绑定在不同环境中相似，则其他 与ARF复杂的因子可能负责调节生长素的反应；这些将 用Turbo-ID鉴定ARF蛋白复合体成分。最后，我会 执行时程RNA-SEQ，然后进行基因调控网络(GRN)分析以评估 光与暗中生长素的转录反应是如何变化的。加起来 突变筛选、ARF DNA结合图谱和GRN将阐明环境如何影响 对刺激的反应，并确定上下文相关信号中的重要因素 在未来的调查中。

Title: Using auxin to understand context-dependent hormone response Project Summary Cells constantly integrate a suite of intrinsic and extrinsic information to coordinate their activities. The suite of stimuli perceived by a cell – the context – can drastically alter the response to a subsequent stimulus. The plant hormone auxin provides a fascinating example of this context-dependent response: auxin regulates diverse phenomena from cell expansion to cell fate specification during all aspects of a plant's life. How the same hormone can elicit such diverse responses depending on the context is unknown. Here I propose work to discover genetic factors required for context-depending auxin response. Seedlings of Arabidopsis thaliana respond oppositely to exogenous auxin when grown in the light versus when grown in darkness. I hypothesize that auxin triggers distinct genetic pathways in light and darkness. Using Arabidopsis as a model, I will test this hypothesis first by performing a mutant screen that will isolate novel factors required for context-dependent and context-independent auxin signaling. I will subsequently assay how the DNA-binding landscape of AUXIN RESPONSE FACTOR (ARF) transcriptional effectors compares in light and dark-grown hypocotyls. If ARF binding varies substantially due to context, I will test whether differences in chromatin accessibility underlies this variation. If ARF DNA-binding is similar across contexts, then other factors in complex with the ARFs are likely responsible for modulating auxin response; these will be investigated using TURBO-ID to identify ARF protein complex components. Finally, I will perform time course RNA-seq followed by Gene Regulatory Network (GRN) analysis to assess how the transcriptional response to auxin changes in the light versus in the darkness. Altogether the mutant screen, ARF DNA-binding profiles, and GRNs will elucidate how context affects the response to a stimulus and identify important factors in context-dependent signaling that can be investigated in the future.