EAPSI: Quantifying Pore Characteristics and Leaf Water Transport Conduits in Three Australian Evergreen Tree Species

在植物中，水从土壤中通过一个复杂的管道网络从根输送到树干、树枝和叶子。当土壤干燥时，植物中的水柱会断裂，导致水运能力下降，如果干旱持续下去，最终会死亡。我们知道，连接树木中相邻的水运管道的孔隙的物理特性与根、树干和树枝的耐旱性有关，但很少有研究关注叶子中的这些孔隙，尽管它们是植物光合作用的门户，因此是整体生长和生存的门户。在这个项目中，研究员将与Brendan Choat ？他是澳大利亚西悉尼大学霍克斯伯里环境研究所的植物水运专家。利用激光和电子高分辨率成像系统测量三种经济上至关重要的常绿树种叶片中的这些相互连接孔。分析孔隙的解剖结构将增加基础知识，并有助于提高干旱引起的森林枯死预测的准确性。虽然叶片是整个植物生长和生产力的门户，但其水力功能的研究远远少于其他植物器官。研究表明，在根、茎和枝中，边缘核/环核形态与抗旱性存在相关性，但这些结构在叶木质部中大多未被量化。在这个项目中，研究员将与Brendan Choat ？他是澳大利亚西悉尼大学霍克斯伯里环境研究所的植物水力学专家。利用共聚焦激光扫描显微镜和电子扫描显微镜对三种经济上至关重要的针叶树种的叶管胞和输注管胞的凹坑和环状核形态进行成像和量化。解剖特征是叶片和土壤-植物-大气模型的必要组成部分；了解边缘坑的形态有助于预测气候变化下植物功能和物种分布的变化。该奖项由美国国家科学基金会和澳大利亚科学院共同资助，隶属于东亚和太平洋暑期研究所项目，支持美国研究生进行暑期研究。

In plants, water is transported from the soil through a complex network of conduits from roots to trunks, branches and leaves. As soils dry, water columns in the plant can break, resulting in a reduced water transport capacity and eventual death if the dry conditions persist, as with drought. We know that the physical characteristics of the pores, which link adjacent water transport conduits in trees, relate to drought tolerance in roots, trunks and branches, but little research has focused on these pores in leaves, despite their being the gateway to plant photosynthesis and therefore overall growth and survival. In this project, the Fellow will work with Dr. Brendan Choat ? an expert in plant water transport at the Hawkesbury Institute for the Environment at Western Sydney University, Australia ? to measure these interconnecting pores in leaves of three economically vital evergreen tree species using laser-based and electron-based high resolution imaging systems. Analyzing the anatomical structure of the pores will increase foundational knowledge and help to enhance accuracy of drought-induced forest dieback predictions.Although leaves are the gateways of overall plant growth and productivity, their hydraulic function has been studied much less than other plant organs. Research has shown that there is a correlation between bordered pit/torus-margo morphology and drought resistance in roots, stems and branches, but these structures remain largely unquantified in leaf xylem. In this project, the Fellow will work with Dr. Brendan Choat ? an expert in plant hydraulics at the Hawkesbury Institute for the Environment at Western Sydney University, Australia ? to image and quantify numerous aspects of pit and torus-margo morphology in leaf tracheids and transfusion tracheids in three economically vital conifer species using confocal laser scanning microscopy and electron scanning microscopy. Anatomical characteristics are necessary components of leaf and soil-plant-atmosphere models; understanding bordered pit morphology may contribute to enhanced predictions of altered plant function and species distributions under changing climate regimes.This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Australia Academy of Science.