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，包括谷物产量、生物量、地上部和根构型、衰老和抗病。荷尔蒙如何调控如此多样化的一系列特征，仍然是生物学中的一个中心问题。这个项目的目标是揭示细胞分裂素是如何调控植物的生长和发育的，特别是关注发生在茎和根中的调控差异。研究人员使用跨学科的方法对细胞分裂素信号的基因调控网络进行实验量化和数学建模。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。这项工作的结果将最终实现对植物的精确操纵，以优化各种农业环境中的表现。该项目的更广泛影响将为本科生、研究生和博士后研究员提供跨学科培训机会。此外，通过当地的伙伴关系，将制定旨在通过参与性活动鼓励中小学生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，刺激芽中的细胞增殖，但在根中抑制细胞增殖。围绕由B型ARR转录因子启动的转录网络，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。一种动态贝叶斯网络方法将被用来从数学上推断介导根和芽中细胞分裂素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，转录网络将被干扰，以确定各种机制在调节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将用于基因表达的全局表征，CHIP-Seq将用于识别转录因子的靶标。通过迭代地使用网络建模来指导实验研究，进而为模型提供进一步的信息，该项目将导致对细胞分裂素信号以及各种转录因子使细胞分裂素能够调节与发育相关的表型的机制的系统水平的理解。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.