ABA-dependent control of plant hydraulics in acclimation to water deficit

植物水力学在适应水分亏缺时依赖于 ABA 的控制

• 批准号: 406910788
• 负责人: Professor Dr. Erwin Grill
• 金额: --
• 依托单位: Lehrstuhl für Botanik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/406910788?language=en
• 关键词: ABA; dependent; control; plant; hydraulics

Water plays a crucial role in terrestrial ecosystems with plants acting as a major factor in water cycling. By dominating the water flux from the soil to atmosphere, plant transpiration is key for terrestrial climate and carbon cycling. Besides its general ecological importance, water availability is the major constraint for higher plant productivity in the field. When subjected to water limitation, plants homeostase their water status by coordinating transpiration with root-mediated water uptake. This leads to altered gas exchange and can result in improved leaf water use efficiency. How this is achieved is only rudimentarily understood. It appears that the plant response to water limitation involves a rapid hydraulic dialog between roots and shoots which itself relies on fundamental plant physiological mechanisms. Water flux within the plant is facilitated by water-conducting aquaporin channels and water use efficiency as well as plant’s gas exchange are governed by the stress hormone abscisic acid (ABA) which is the key factor in adjusting plant responses to drought. Different ABA sensitivities and distinct ABA signalling responses of cells and plant organs are required for coordinated water homeostasis.Understanding the long distance-coordinated water homeostasis of plants beyond these principles has been a challenge. Progress in this field has been very slow over the last decade because of the experimental difficulties in defining molecular mechanisms and to test them in plants. Initiated by recent advances in the field of ABA signaling and the control of plant hydraulics, the joint French-German research team feels to be in an excellent position to achieve a breakthrough on this enigma. The proposed ABAqua project will use and generate frontline understanding of ABA signalling pathways and aquaporin regulation to elucidate how water homeostasis is achieved through communication between roots and leaves. An emphasis of the project is to answer how the different hormone sensitivities and actions of ABA on root and guard cell hydraulics are realized and relayed to water-conducting aquaporins. Detailed molecular analysis of prototypic ABA signaling modules targeting aquaporins will be employed in combination with phosphoproteomics and expression of deregulated signaling components in Arabidopsis. Analyses at the whole-plant level will include grafting experiments and tissue-specific complementation of ABA signaling and aquaporin mutants. These analyses will reveal the key hydraulic regulatory mechanisms and their impact on gas exchange in plants under well-watered condition and drought. The emerging principles of plant’s water homeostasis, affecting gas exchange and concomitant changes in water use, will provide a mechanistic basis for improved prediction of carbon cycling and plant productivity under water limitation.

水在陆地生态系统中起着至关重要的作用，植物是水循环的主要因素。通过主导从土壤到大气的水通量，植物的翻译是陆地气候和碳循环的关键。除了其一般的生态重要性外，水的可用性是该领域较高植物生产力的主要限制。当受到水的限制时，通过与根介导的水吸收协调蒸腾作用，将体内平衡酶植入其水状态。这会导致气体交换改变，并可能提高叶水利用效率。如何实现这一目标只有一定的理解。看来植物对水限制的反应涉及根和芽之间的快速氢化对话，这本身依赖于基本的植物生理机制。植物内的水通量是通过水电通道和水利用效率以及植物的气体交换来制备的，而植物的气体交换受压力马脱甲基甲酸（ABA）的控制，这是调整植物对干旱反应的关键因素。协调的水稳态需要不同的ABA敏感性和细胞和植物器官的独特的ABA信号反应。理解这些原理以外的植物的长距离协调水稳态是一个挑战。在过去的十年中，该领域的进展非常缓慢，因为实验难度定义分子机制并在植物中测试它们。由ABA信号传导领域的最新进展和对植物水力学的控制发起的，法国 - 德国联合研究小组认为，在这一谜中取得突破是一个极好的地位。拟议的ABAQUA项目将使用并产生对ABA信号通路和Aquaporin调节的一线理解，以阐明通过根和叶之间的交流如何实现水稳态。该项目的重点是回答如何实现ABA对根和防护细胞水合物的不同同性敏感性和作用，并将其传递到水导通的水通道蛋白。靶向水通道蛋白的原型ABA信号模块的详细分子分析将与磷酸蛋白质组学结合使用，并在拟南芥中进行放松管制的信号成分的表达。在整个植物水平上进行的分析将包括嫁接实验以及ABA信号传导和水通道蛋白突变体的组织特异性完成。这些分析将揭示关键的水解调节机制及其对植物中植物中气体交换的影响。植物水体内稳态的新兴原则，影响气体交换和用水的伴随变化，将为改善碳循环和植物生产力的预测提供机械基础。