IOS Proposal: RUI: Auxin dynamics during vascular development in the model woody plant Populus

木本植物提供重要的能源和建筑材料，并在固碳、水文循环和生境构建中发挥重要作用。尽管木本植物提供了许多服务，但人们对木本茎如何发育以及茎的老木质部分和年轻的非木质生长之间如何形成维管连接知之甚少。这个项目的主要目标是利用模式植物黑杨来确定植物激素生长素的运动如何控制木本植物的维管发育。利用化学分析、遗传修饰和显微技术相结合的方法，可以跟踪生长素从幼叶发育到木质茎下的运动，并与叶脉形成的时间进程有关。生长素的运动也将被化学抑制剂破坏，以确定生长素运输对木材结构的影响。这项工作有望阐明木本植物的维管系统是如何建立的，以及激素生长素是如何决定茎的重要物理特性的。维管系统是向植物的其他部分供应水分和分配糖的静脉网络。特别是，液体渗透性对于提高植物材料(例如木材)的利用率以及植物的存活非常重要，并在维管发育过程中决定，这一过程可能受到生长素流动的调节。该项目还为对科学感兴趣的本科生在学年期间和通过暑期实习提供了多种培训机会。预计该项目将鼓励10名或更多的本科生从事与植物生物学相关的科学职业，包括林业、碳循环和开发生物燃料的新原材料。

Woody plants provide critical sources of energy and building materials and play important roles in carbon sequestration, hydrologic cycles, and habitat assemblies. Despite the many services provided by woody plants, very little is known about how woody stems develop and how vascular connections are formed between the older woody portions of a stem and the younger, non-woody growth. The main objective of this project is to determine how movement of the plant hormone auxin controls vascular development in a woody plant using the model species Populus tremula x alba. By using a combination of chemical analyses, genetic modification and microscopy, the movement of auxin will be tracked from the young developing leaves to the woody stem below and related to the time course of vein formation. The movement of auxin will also be disrupted with chemical inhibitors in order to determine the effects of auxin transport on wood structure. This work is expected to shed light on how the vasculature -- the network of veins that supply leaves with water and distribute sugars to the rest of the plant -- is established in woody plants and how the hormone auxin determines important physical properties of the stem. In particular, liquid permeability is important for improved utilization of plant materials (e.g., wood) as well as plant survival and is determined during vascular development, a process that may be regulated by auxin flow. This project also provides multiple training opportunities for undergraduates interested the sciences both during the academic year and through summer internships. It is expected that this project will encourage ten or more undergraduates to pursue careers in science related to plant biology including forestry, carbon cycling and the development of new raw materials for biofuels.