Collaborative Research: Resistance, Repair and Redundancy: Traits that Protect Shrubs against Drought-induced Hydraulic Failure

合作研究：抵抗、修复和冗余：保护灌木免受干旱引起的水力衰竭的特性

• 批准号: 0641765
• 负责人: Jochen Schenk
• 金额: $ 36.4万
• 依托单位: CSU Fullerton Auxiliary Services Corporation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0641765&HistoricalAwards=false
• 关键词: Collaborative; Research; Resistance; Repair; Redundancy

In engineering terms, the hydraulic system of a woody plant is a "negative pressure flowsystem" in which conducting cells in the wood (xylem) are linked from roots to leaves.This type of hydraulic system is prone to failure due to the introduction of air bubbles,which create embolisms. Plants frequently develop embolisms in their hydraulic systems, especially under water limited conditions.Whether man-made or natural, a pressure flow system can be protected fromfailure in three ways: resistance, reparability, and redundancy. Resistance to hydraulicfailure in plants is fairly well understood and involves the thickness of cells walls inconducting cells and in the surrounding matrix of thick-walled cells (fibers). Reparabilityafter failure depends on living cells in and adjacent to xylem. Redundancy reflects thenumber of root to leaf conducing pathways and the degree of their interconnectedness(hydraulic integration). The unique arrangements of conducting cells, supporting fibers,and living cells in different species suggest that tradeoffs occur among these three types of protections. To date, interactions among them are virtually unknown.The proposed research questions whether the relative amounts of different typesof protection change with increasing habitat aridity in dominant shrub species frommultiple lineages along transcontinental aridity gradients in North America, SouthAmerica, and Australia. Methods will involve standard techniques used to study thestructure of plant xylem and the use of dye tracers to characterize three-dimensionalpathways of water transport. Xylem function studies will quantify resistance toembolisms and reparability of experimentally induced embolisms. This study will be thefirst to simultaneously examine the relative roles of redundancy, resistance and repair inprotecting plants from hydraulic failure.Results from this study will aid researchers and land managers in understandinghow hydraulic protection influences shrub survival during global climate change anddesertification. Students of different ages, ethnic, and cultural backgrounds willexperience the scientific process as they participate in every aspect of the research.

在工程术语中，木本植物的液压系统是一个“负压流动系统”，其中木材（木质部）中的传导细胞从根连接到叶。这种类型的液压系统容易由于引入气泡而发生故障，气泡会产生栓塞。植物的水力系统经常发生栓塞，特别是在水有限的条件下。无论是人工的还是自然的，压力流系统可以通过三种方式防止故障：阻力、可修复性和冗余性。植物对水力破坏的抵抗力是相当好理解的，它涉及到细胞壁的厚度、传导细胞和厚壁细胞（纤维）周围的基质。破坏后的再循环性取决于木质部内和邻近木质部的活细胞。红度反映了根到叶传导途径的数量及其相互联系的程度（水力整合）。不同物种中传导细胞、支持纤维和活细胞的独特排列表明，这三种保护之间存在权衡。迄今为止，它们之间的相互作用几乎是unknowed.The拟议的研究问题是否相对量的不同类型的保护变化与生境干旱的优势灌木物种从多个谱系沿着横贯大陆的干旱梯度在北美，南美和澳大利亚。方法将涉及用于研究植物木质部结构的标准技术和使用染料示踪剂来表征水运输的三维途径。木质部功能研究将量化栓塞的抵抗力和实验诱导栓塞的可修复性。这项研究将是第一项同时研究冗余、抗性和修复在保护植物免受水力破坏方面的相对作用的研究。这项研究的结果将帮助研究人员和土地管理者了解水力保护如何影响全球气候变化和荒漠化期间灌木的生存。不同年龄，种族和文化背景的学生将体验科学过程，因为他们参与研究的各个方面。