Transcriptional Regulation of the Cytokinin Signaling Network

植物激素细胞分裂素调节许多重要的农艺性状，包括粮食产量、生物量、茎和根结构、衰老和抗病性。一种激素如何调节如此多样的性状，仍然是生物学中的一个核心问题。该项目的目标是揭示细胞分裂素如何调节植物生长和发育，特别关注发生在茎和根中的调节差异。研究人员使用跨学科的方法来实验量化和数学模型基因调控网络潜在的细胞分裂素信号。通过他们的工作获得的理解将有助于预测细胞分裂素功能的扰动如何改变植物的发育。这项工作的结果最终将使精确操纵植物在各种农业环境中优化性能成为可能。项目的广泛影响将为本科生、研究生和博士后提供跨学科的培训机会。此外，将通过地方伙伴关系，制定旨在通过参与活动鼓励中小学生的教育和科学意识的项目。细胞分裂素以一种潜在的组织特异性方式调节植物的生长和发育，在茎部刺激细胞增殖，但在根部抑制细胞增殖。关注由b型ARR转录因子启动的转录网络，它在转录级联的顶端起作用，介导细胞分裂素反应，研究人员使用一套完整的实验方法来剖析细胞分裂素调节发生的机制。动态贝叶斯网络方法将用于从数学上推断介导细胞分裂素在根和芽中的反应的基因调控网络，并确定与细胞分裂素的组织特异性效应相关的独特调控方面。利用遗传方法，转录网络将受到干扰，以确定各种机制在介导信号输出中所起的作用，干扰集中在调节细胞分裂素信号敏感性的关键元件和与信号网络相关的下游转录因子上。RNA-Seq将用于全局表征基因表达，ChIP-Seq将用于鉴定转录因子的靶点。通过反复使用网络建模来指导实验研究，从而进一步为模型提供信息，该项目将导致对细胞分裂素信号传导的系统水平理解，以及各种转录因子使细胞分裂素介导发育相关表型的机制。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The plant hormone cytokinin regulates many agronomically important traits, including grain yield, biomass, shoot and root architecture, senescence, and disease resistance. How a hormone regulates such a diverse array of traits remains a central question in biology. The goal of this project is to uncover how cytokinins regulate plant growth and development, with a particular focus on differences in regulation that occur in the shoot and root. Investigators use interdisciplinary methods to experimentally quantify and mathematically model gene regulatory networks underlying cytokinin signaling. The understanding gained by their work will facilitate predictions for how perturbation of cytokinin function alters plant development. Outcomes of this work will ultimately enable precise manipulation of plants to optimize performance in various agricultural settings. Broader impacts of the project will provide interdisciplinary training opportunities for undergraduate students, graduate students and postdoctoral fellows. In addition, through local partnerships, programs will be developed that aim to encourage education and science awareness among elementary and middle school students through participatory activities.Cytokinin modulates plant growth and development in a potentially tissue specific manner, stimulating cell proliferation in the shoot but inhibiting it in the root. Focusing on transcriptional networks initiated by type-B ARR transcription factors, which act at the top of a transcriptional cascade to mediate the cytokinin response, investigators use an integrated set of experimental methods to dissect the mechanisms by which cytokinin regulation occurs. A dynamic Bayesian network approach will be used to mathematically infer gene regulatory networks that mediate the cytokinin response in roots and shoots and identify unique regulatory aspects that correlate with the tissue specific effects of cytokinin. Using genetic approaches the transcriptional networks will be perturbed to determine the role that various mechanisms play in mediating signaling output, with perturbations focused on key elements that regulate cytokinin signaling sensitivity and downstream transcription factors associated with the signaling network. RNA-Seq will be used to globally characterize gene expression and ChIP-Seq to identify targets of the transcription factors. By iteratively using network modeling to guide experimental investigations, which in turn further inform the model, this project will result in a systems level understanding of cytokinin signaling and the mechanism by which various transcriptional factors enable cytokinin to mediate development associated phenotypes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.