CAREER: Linking phloem anatomy and physiology with whole plant changes in resource allocation

每年，许多树在春天长新叶，秋天落叶，然后开花结果。这些变化包括资源通过植物维管系统进出器官的运动，通常在短时间内以快速的速度进行。尽管这些变化对园艺、农业和森林再生具有重要意义，但人们对这些时期维管系统发生的变化知之甚少。该项目使用两种新的方法来研究碳运输和血管解剖学，这将解决关于糖运输的基本问题，它的稳定性以及它如何影响植物生长的整个植物生命周期。这项工作对于理解季节性在决定植物生长和繁殖中的作用至关重要，并将促进对影响树木生长、作物生产和植物生态的过程的理解。该项目位于一所研究和教育紧密结合的初级本科院校，将在实验室和课堂上培养年轻科学家和指导学生。学生们将帮助组织一个以植物季节性为重点的公民科学项目，并将更广泛的社区与科学和当地环境联系起来。这个项目的目标是更好地定义韧皮部在控制资源分配中的作用。有三个主要的研究目标。(1)研究韧皮部液通量和解剖学与花大小和生境亲和性的关系。本研究将集中在测量碳运输和表征韧皮部解剖、花发育和花大小之间的关系在至少30个密切相关的物种。(2)研究叶片衰老过程中韧皮部运输是否与养分再动员和色素生成相耦合。本研究将探讨衰老叶片韧皮部运输速度、叶片化学和养分通量之间的关系。该项目的一部分将测试韧皮部运输减少是否会引发叶片颜色变化。(3)确定韧皮部解剖结构对幼苗分配和树木生长的影响。本研究将探讨在幼苗发育过程中韧皮部运输速度的变化是否可以通过维管结构来预测。它还将确定韧皮部解剖如何使用由首席研究员开发的新的免疫定位协议的高度。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。

Every year many trees produce new leaves in the spring, lose leaves in the fall, and produce flowers and fruit. These changes involve the movement of resources into and out of organs through the plant vascular system, often at a rapid pace over a short period of time. Despite the importance of these changes to horticulture, agriculture and forest regeneration, relatively little is known about what happens in the vascular system during these time periods. This project uses two new methods for studying carbon transport and vascular anatomy that will address fundamental questions about sugar transport, its stability and how it influences plant growth throughout the plant life cycle. This work is critical to understanding the role of seasonality in determining plant growth and reproduction and will advance the understanding of processes that influence tree growth, crop production, and plant ecology. Being based at a primary undergraduate institution, where research and education are strongly intertwined, this project will train young scientists and mentor students in the laboratory and classroom. Students will help organize a citizen science project focused on plant seasonality and connecting the broader community with science and the local environment. The goal of this project is to better define the role of the phloem in controlling resource allocation. There are three central research aims. (1) Characterize how phloem sap flux and anatomy relate to floral size and habitat affinity. This research will focus on measuring carbon transport and characterizing the relationships between phloem anatomy, floral development and floral size in at least thirty closely related species. (2) Investigate whether phloem transport is coupled with nutrient re-mobilization and pigment production during leaf senescence. This research will examine the relationship between phloem transport velocity, leaf chemistry and nutrient flux in senescing leaves. One part of this project will test whether decreased phloem transport could trigger leaf color change. (3) Determine how phloem anatomy influences seedling allocation and tree growth. This study will investigate whether changes in phloem transport velocity can be predicted during seedling development based on vascular architecture. It will also determine how phloem anatomy scales with height using new immunolocalization protocols developed by the principal investigator.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.