CAREER: The coordination of leaf hydraulics, structure and gas exchange

职业：叶片水力学、结构和气体交换的协调

• 批准号: 0753233
• 负责人: Lawren Sack
• 金额: $ 82.88万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0753233&HistoricalAwards=false
• 关键词: CAREER; coordination; leaf; hydraulics; structure

CAREER: The coordination of leaf hydraulics, structure and gas exchangeThe leaf hydraulic conductance (Kleaf) is a critical bottleneck in whole-plant liquid transport, associated with the tremendous diversity across species in leaf structure (thickness, shape, venation architecture, stomatal pore area) and maximum rates of gas exchange. Additionally, Kleaf is dynamically linked with gas exchange for given species. In a series of systematic and mechanistic studies, the following specific hypotheses will be tested: (1) Kleaf imposes a consistent proportion of resistance in the plant hydraulic system, constraining maximum rates of gas exchange; (2) Kleaf is constrained by venation architecture; (3) Kleaf is dynamic, declining in low irradiance, and during leaf dehydration and ageing, due to xylem blockage and/or changes in membrane properties; these dynamics are importantly related to changes in gas exchange; (4) Kleaf is coordinated across species with structural traits associated with water flux through the leaf and gas exchange per area. This work will focus on both the mechanistic bases for these processes and the implications for whole plant function. Native Hawaiian species and invasive species will be studied in common gardens and across the dramatic natural moisture and soil age gradients of Hawai'i. Special focus will be given to the variation of of leaf hydraulic properties in the heteroblastic stages of native Acacia koa. The study will be expanded to include arboretum-grown species of Araceae with exceptionally diverse leaves. These studies will break new ground toward understanding of the integration of water transport and carbon assimilation at their nexus in the leaf. The work will provide detailed information of the extent, variation, mechanistic basis and dynamic nature of the role of leaf hydraulic conductance in the flow of water through plants, and in the evolution and function of diversity in leaf traits. The research will be integrated with undergraduate and graduate course teaching at University of Hawai'i, and with a new mentorship program to provide increased access for native Hawaiians to scientific training and careers, based on study of the unique, fascinating Hawaiian flora. In the Integrated Mentorship in Hawaiian Research, Education and Outreach, indigenous undergraduate students will be mentored part-time during semesters and full-time during summers in research, curriculum development, and outreach, grounded in Hawaiian plant biology. Mentored students will disseminate knowledge to the wider community by designing web curricula, giving educational tours, and by presenting annually in colleges and high schools, and at scientific meetings. The integrated research and education will contribute fundamentally to the understanding of leaf physiology, evolution and functional ecology; provide access for native Hawaiians to science; create resources on Hawaiian plant biology for scientists and educators; and increase global awareness and understanding of the unique Hawaiian biota.

职业：叶片水力学、结构和气体交换的协调叶片水力导度（Kleaf）是整株液体运输的关键瓶颈，与不同物种的叶片结构（厚度、形状、脉序结构、气孔面积）和最大气体交换速率的巨大差异有关。 此外，Kleaf与给定物种的气体交换动态相关。 在一系列系统和机理研究中，将检验以下特定假设：（1）Kleaf在工厂水力系统中施加一致的阻力比例，限制最大气体交换速率：（2）Kleaf受脉序结构限制;（3）Kleaf是动态的，在低光照下，由于木质部堵塞和/或膜特性的变化，在叶片脱水和衰老过程中，Kleaf下降;这些动态与气体交换的变化有重要关系;（4）Kleaf在物种间具有协调性，其结构特征与通过叶片的水通量和单位面积的气体交换有关。 这项工作将集中在这些过程的机械基础和整个植物功能的影响。 夏威夷本土物种和入侵物种将在普通花园中进行研究，并跨越夏威夷引人注目的自然水分和土壤年龄梯度。 特别关注的是本地相思树在异胚阶段叶片水力特性的变化。 这项研究将扩大到包括树木园生长的天南星科物种与异常多样化的叶子。这些研究将为理解叶片中水分运输和碳同化在其关系中的整合开辟新的天地。 这项工作将提供有关叶片水力传导度在植物水分流动中的作用的程度、变化、机制基础和动态性质以及叶片性状多样性的进化和功能的详细信息。 这项研究将与夏威夷大学的本科和研究生课程教学相结合，并与一个新的导师计划相结合，以提供更多的机会，为夏威夷土著人的科学培训和职业生涯，基于对独特的，迷人的夏威夷植物群的研究。 在夏威夷研究、教育和外联的综合导师制中，土著本科生将在学期期间接受兼职辅导，在夏季接受全职辅导，从事夏威夷植物生物学的研究、课程编制和外联工作。 接受辅导的学生将通过设计网络课程、进行教育性图尔斯参观以及每年在大学和高中以及科学会议上发表演讲，向更广泛的社区传播知识。 综合研究和教育将从根本上促进对叶生理学，进化和功能生态学的理解;为夏威夷土著人提供科学途径;为科学家和教育工作者创建夏威夷植物生物学资源;并提高全球对夏威夷独特生物群的认识和理解。