Decoding drought tolerance

解码耐旱性

• 批准号: RGPIN-2019-04360
• 负责人: Hacke, Uwe
• 金额: $ 4.01万
• 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: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=737581
• 关键词: Decoding; drought; tolerance

The health of larger organisms depends on the proper function of their circulatory or vascular systems. Human health is often compromised by cardiovascular diseases, and the same is true for plants. Plant health depends on the ability of the vascular tissue to distribute water, nutrients, and sugar across the plant body. Importantly, transport processes in plants are susceptible to environmental factors such as drought and frost. Both of these factors can trigger the formation of air embolism in xylem conduits, and this will make the supply of water to leaves more difficult. As a result of xylem blockage, leaves will reduce gas exchange, and in more severe cases this will be followed by dieback and mortality. Adverse environmental conditions are likely to also reduce sugar transport in the phloem. Drought is the main factor that compromises vascular function in plants. It is the most complex and arguably the most limiting stress factor for plant growth worldwide, in agricultural fields and forests alike. In addition, drought is often associated with fire and insect outbreaks. Despite the importance of drought in forestry and agriculture, we still lack some basic understanding of how plants cope with drought. This topic has recently received much attention among tree physiologists, as accumulating reports of drought-induced forest tree dieback have raised questions about the exact mechanism of tree dieback. The long-term goals of my research program are to understand the multiple effects of drought on vascular function and to explore how species and genotypes differ in how they cope with water shortage. The short-term objectives of my research are to: (1) Study the dynamics of whole-plant hydraulic conductance; (2) Analyze the unique cellular signatures of drought and insect defoliation in tree rings; (3) Quantify genetic variation of drought tolerance in white spruce seedlings from different climate regions; and (4) Explore how drought impacts the development and putative function of phloem. As global temperatures and precipitation regimes continue to change, there is a need for training the next generation of scientists to advance the field of drought physiology. The proposed research program will train 2 Ph.D., 2 M.Sc., and 5 undergraduate students. The knowledge gained from this research will allow us to select and eventually engineer plants with drought tolerance and growth characteristics that will match current and future challenges in their growing environment.

较大生物体的健康取决于其循环或血管系统的正常功能。人类健康常常受到心血管疾病的影响，植物也是如此。植物的健康取决于维管组织在植物体内分配水、养分和糖的能力。重要的是，植物的运输过程容易受到干旱和霜冻等环境因素的影响。这两个因素都会引发木质部导管中空气栓塞的形成，这将使向叶子供水变得更加困难。由于木质部堵塞，叶子会减少气体交换，在更严重的情况下，随后会出现枯萎和死亡。不利的环境条件也可能减少韧皮部的糖运输。干旱是损害植物维管功能的主要因素。它是世界范围内农田和森林植物生长最复杂且可以说是最具限制性的胁迫因素。此外，干旱常常与火灾和昆虫爆发有关。尽管干旱对林业和农业很重要，但我们仍然对植物如何应对干旱缺乏一些基本了解。这个话题最近受到了树木生理学家的广泛关注，因为越来越多的干旱引起的森林树木枯死的报告提出了关于树木枯死的确切机制的疑问。我的研究计划的长期目标是了解干旱对血管功能的多重影响，并探索物种和基因型在应对缺水方面的差异。我的研究的短期目标是：（1）研究全厂水力传导的动态； (2) 分析树木年轮中干旱和昆虫落叶的独特细胞特征； (3) 量化不同气候地区白云杉幼苗耐旱性的遗传变异； (4) 探索干旱如何影响韧皮部的发育和假定功能。随着全球气温和降水状况的不断变化，需要培训下一代科学家来推进干旱生理学领域的发展。拟培养博士生2名、硕士生2名、本科生5名。从这项研究中获得的知识将使我们能够选择并最终设计具有耐旱性和生长特性的植物，以应对其生长环境中当前和未来的挑战。