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

每年，许多树都会在春天长出新叶，秋天落叶，开花结果。这些变化涉及资源通过植物维管系统进出器官，通常在短时间内以快速的速度进行。尽管这些变化对园艺、农业和森林更新很重要，但人们对这些时期血管系统中发生的事情知之甚少。这个项目使用了两种新的方法来研究碳运输和维管解剖学，这两种方法将解决关于糖运输、其稳定性以及它如何在植物整个生命周期中影响植物生长的基本问题。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。该项目以一所研究和教育紧密交织在一起的小学本科院校为基础，将在实验室和课堂上培养年轻科学家并指导学生。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确定韧皮部在控制资源分配中的作用。研究的核心目标有三个。(1)描述韧皮部液流和解剖结构与花大小和生境亲和力之间的关系。这项研究将集中于测量碳运输，并表征韧皮部解剖、花发育和花大小之间的关系，至少在30个近缘物种中。(2)探讨叶片衰老过程中韧皮部运输是否与营养物质的再动员和色素的产生有关。本研究将探讨衰老叶片韧皮部运输速度、叶片化学成分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苗木配置和树木生长的影响。本研究将探讨能否根据维管结构来预测幼苗发育过程中韧皮部运输速度的变化。它还将确定如何使用首席研究员开发的新的免疫定位方案来调整韧皮部解剖结构。这一奖项反映了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。

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.