Research on plant-water relations examining physiological, structural, and molecular mechanisms of plant responses to their environment

植物与水关系的研究，考察植物对其环境反应的生理、结构和分子机制

• 批准号: RGPIN-2014-04137
• 负责人: Hacke, Uwe
• 金额: $ 2.19万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=610852
• 关键词: Research; plant; water; relations; examining

Water availability plays an important role in maintaining the health and productivity of both managed and natural ecosystems. In the light of global changes in temperature and precipitation patterns, it is becoming increasingly important to better understand physiological and molecular responses of plants to water stress. The impact of changes in temperature and precipitation on Canada’s boreal forest is expected to be greater than on temperate and tropical forests. Forests in Canada are likely to be affected not only by direct impacts of drought but also by natural disturbances that are brought on by drought (e.g., fire and insects). Water availability is often a limiting factor for the productivity of crops and the survival of plantation trees. Drought also reduces tree productivity and survival across many forest ecosystems. Whether a tree lives or dies in response to a drought episode depends in part on maintaining the integrity of its ‘plumbing system’, which is positioned between the dry soil and the even dryer atmosphere. The xylem (wood) is the principal water-conducting tissue in vascular plants. The hydraulic system of plants depends on a unique but inherently unstable mechanism. As the soil dries, water columns in the xylem may break, causing an air blockage (embolism). As drought increases, more embolism forms in the wood until leaves do not receive enough water to survive. We will study the hydraulic properties of different plant organs (leaves, stems, and roots) to determine which part of the plant is most vulnerable to embolism formation and loss of hydraulic conductivity. While xylem allows for efficient transport of water and nutrients over long distances (over 100m in redwood trees), aquaporins (membrane-based water channels) facilitate water movement on a cellular scale. Before water enters the xylem in roots, and after it exits the xylem in leaf veins, it flows through living cells, via aquaporins. Water channels are dynamically regulated and are likely to play an important role in a plant’s response to changing environments. We will study how aquaporins impact water flow in living cells of roots and leaves, in order to understand their role in drought stress physiology. Findings will be interpreted in a whole-plant context. The proposed research will integrate water relations research at the molecular, organ, organismal scales.

水的可用性在维持托管和自然生态系统的健康和生产力方面起着重要作用。鉴于温度和降水模式的全球变化，更好地了解植物对水胁迫的物理和分子反应变得越来越重要。预计温度和降水对加拿大北方森林的影响将大于温度和热带森林。加拿大的森林不仅可能受到干旱的直接影响，而且会受到干旱带来的自然灾害的影响（例如火灾和昆虫）。 供水通常是农作物生产力和植物树生存的限制因素。干旱还降低了许多森林生态系统的树木生产力和生存。一棵树是生命还是死于干旱发作，部分取决于维持其“管道系统”的完整性，该系统位于干燥的土壤和均匀的干燥机氛围之间。 木质部（木材）是血管植物中的主要水导管组织。植物的水解系统取决于独特但固有的不稳定机制。随着土壤干燥，木质部中的水柱可能会破裂，从而导致空气块（栓塞）。随着干旱的增加，木材中有更多的栓塞形成，直到叶子没有得到足够的水来生存。我们将研究不同植物器官（叶子，茎和根）的水解特性，以确定植物的哪一部分最容易形成栓塞和水解电导率的丧失。 木质部允许在长距离（红木树中超过100m）上有效地运输水和养分，而水通道蛋白（基于膜的水通道）促进了在细胞尺度上的水运动。在水中进入木质部之前，然后在叶静脉中退出木质部后，它通过水通道蛋白流过活细胞。水道受到动态调节，并且可能在植物对不断变化的环境的反应中发挥重要作用。我们将研究水通道蛋白如何影响根和叶的活细胞中的水流，以了解它们在干旱胁迫生理中的作用。发现将在整个植物上下文中进行解释。拟议的研究将在分子，器官量表上整合水关系研究。