Vascular Pattern Formation in Leaves of Arabidopsis and Rice

项目负责人：Timothy Nelson，耶鲁大学提议拟南芥叶片维管模式形成本项目旨在了解植物叶片脉网络的模式。生长素信号传导和极性生长素运输（PAT）在许多发育过程中起着重要的作用，包括静脉模式和叶分制，即茎上叶子的排列。然而，每种情况下的生长素模式依赖于一个不同的背景；在发育的正确时间和地点，某些细胞和其中的某些途径以一种独特的方式对生长素作出反应。也就是说，生长素作用的上游和下游都有其独特的特点。该项目的先前结果表明，肌醇信号调节静脉模式。该项目将使用遗传学、细胞生物学和生物化学来验证这样一种假设，即特定的磷酸肌醇信号在发育中的叶组织的细胞空间信息和促进该组织中静脉模式的更具体的PAT现象之间提供了联系。结果将包括肌醇酶与PAT相关的膜运输机制的共定位，磷酸肌醇信号与膜运输蛋白之间的调节相互作用的定义，以及血管细胞中活性肌醇底物和途径组分的鉴定。随着我们对静脉形态和分化的了解的增加，它将为影响发育、发病防御和生理（如C4光合作用、资源分配、营养吸收等）提供手段，所有这些都依赖于静脉。更广泛的影响：该项目为学生，博士后科学家和少数民族暑期研究实习生提供培训工具。该项目是PI向非理工科本科生教授生物学的一个插图来源，其中许多人对科学政策和科学与社会问题感兴趣。

PI: Timothy Nelson, Yale UniversityProposal IOS-0718881Vascular Pattern Formation in Leaves of ArabidopsisThis project seeks to understand the patterning of leaf venation networks in plant. A role for auxin signaling and polar auxin transport (PAT) has been demonstrated recently in many developmental processes, including vein patterning and phyllotaxy, which is the arrangement of leaves on a stem. However, each case of auxin patterning relies on a distinct context; certain cells and certain pathways within them are made auxin-responsive in a manner unique to that process, at the right time and place in development. That is, there are unique features both upstream and downstream of auxin''s role. Prior results from this project suggest that inositol signaling regulates vein patterning. This project will use genetics, cell biology and biochemistry to test the hypothesis that specific phosphoinositol signals provide a connection between cellular spatial information in developing leaf tissue and the more specific PAT phenomena that facilitate vein patterns in that tissue. The results would include the colocalization of inositol enzymes with the endomembrane traffic machinery associated with PAT, the definition of regulatory interactions among phosphoinositol signals and endomembrane traffic proteins, and the identification of active inositol substrates and pathway components in vascular cells. As our understanding of vein patterning and differentiation increases, it will provide a means to influence development, pathogenesis defense, and physiology (e.g., C4 photosynthesis, resource allocation, nutrient uptake, etc), all of which depend on veins. Broader Impacts: This project serves as a training vehicle for students, postdoctoral scientists, and minority summer research interns. The project is a source of illustrations for the PI''s teaching of biology to non-science undergraduates, many of whom have interest in working on science policy and science & society issues.