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

每年许多树在春天长出新叶，秋天落叶，然后开花结果。这些变化涉及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、农业和森林再生很重要，但人们对这些时期血管系统发生的变化知之甚少。该项目使用两种新方法来研究碳运输和血管解剖，这将解决有关糖运输，其稳定性以及它如何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方面的作用至关重要，并将促进对影响树木生长，作物生产和植物生态学的过程的理解。该项目设在一个研究和教育密切相关的主要本科院校，将在实验室和课堂上培训年轻科学家和指导学生。学生将帮助组织一个公民科学项目，重点是植物的季节性，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)描述韧皮部液流和解剖学如何与花的大小和栖息地亲和力相关。这项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)调查韧皮部运输是否与叶片衰老过程中的养分再动员和色素产生相耦合。本研究将探讨韧皮部运输速度，叶片化学和养分流量之间的关系在衰老叶片。这个项目的一部分将测试韧皮部运输的减少是否会引发叶色变化。(3)确定韧皮部解剖如何影响苗木分配和树木生长。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根据维管结构来预测。它还将确定如何韧皮部解剖尺度与高度使用新的免疫定位协议开发的首席investigator.This奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

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.