The sequence of drought-induced physiological and anatomical events in woody perennial crops

加拿大的农业食品部门正面临着由于持续气候变化造成的干旱所带来的前所未有的挑战。2001年至2002年的全国干旱造成农业生产损失36亿美元，国内生产总值下降约58亿美元。2017年的干旱导致了不列颠哥伦比亚省最严重的野火季节，对作物产量和质量产生了严重的负面影响。 作物在干旱条件下的表现取决于根、茎和叶水平过程的成功协调。这包括有效的气孔调节和根系木栓化，以避免过多的水分流失到大气和土壤中。干旱引起的死亡率主要与木质部水力衰竭有关，气体栓塞阻碍了水分从根到叶的运输。了解干旱引起的生理和解剖事件的顺序将有助于（a）选择具有更好抗旱性的作物基因型和（B）发展可持续的灌溉做法。我最近对木本多年生作物的干旱胁迫反应的研究已经产生了一种新的方法来预测叶水平上的过程特定的胁迫阈值，阐明了体内茎木质部栓塞的易感性和储存，并揭示了栓塞修复不是由根压驱动的。 我的研究计划的长期目标是阐明作物的水分需求，通过节水促进可持续农业。在我的计划中，短期目标是（a）确定与气孔关闭和膨压损失相关的胁迫阈值，（B）确定木质部水分运输和储存的耦合，以及（c）确定响应干旱胁迫的根系吸水的动态变化。 我将使用传统和尖端测量工具的组合来阐明干旱下的作物表现。Canadian Light Source的X射线计算机显微断层扫描将为木质部功能，栓塞易感性/体内修复和3D植物解剖提供前所未有的见解。荧光显微镜将用于研究形成层和薄壁组织的细胞活力。根的水力功能和水分运输途径将使用压力探针方法进行评估。使用Scholander型压力室，水势法将用于确定水分状况、胁迫阈值和植物脱水阶段。将建立一个微型蒸渗仪平台，以控制土壤湿度和监测植物蒸腾失水。我的研究项目为3名博士，3名硕士和5名本科生提供了机会。我的研究团队将由不同的HQP组成，实验室成员可以像队友一样茁壮成长。这将创造一个支持科学协作性质的实验室环境。我将确保每个人都得到公平的对待（平等），并感受到研究团队的一部分（包容性），并为HQP实现科学和专业目标提供平等的机会。

Canada's agri-food sector is facing unprecedented challenges caused by drought due to ongoing climate change. The 2001 to 2002 national drought has resulted in $3.6 billion in losses in agricultural production and gross domestic product fell by around $5.8 billion. The 2017 drought resulted in the worst wildfire season in British Columbia with severe negative impacts on crop yield and quality. Crop performance under drought depends on a successful coordination of processes at root, stem, and leaf level. This includes efficient stomatal regulation and root suberization to avoid excessive water loss to the atmosphere and soil, respectively. Drought-induced mortality is predominantly linked to xylem hydraulic failure by gas embolism blocking water transport from roots to leaves. Knowledge about the sequence of drought-induced physiological and anatomical events will facilitate (a) the selection of crop genotypes with improved drought resistance and (b) the development of sustainable irrigation practices. My recent research into drought stress responses of woody perennial crops has resulted in a novel approach to predict process-specific stress thresholds at leaf level, elucidated in-vivo stem xylem embolism susceptibility and storage, and revealed that embolism repair is not driven by root pressure. The long-term objective of my research program is to elucidate crop water requirements to promote sustainable agriculture through water savings. Within my program, the short-term objectives are to (a) identify stress thresholds associated with stomatal closure and turgor loss, (b) determine the coupling of xylem water transport and storage, and (c) identify the dynamic changes in root water uptake in response to drought stress. I will use a combination of traditional and cutting-edge measurement tools to elucidate crop performance under drought. X-ray computed microtomography at Canadian Light Source will provide unprecedented insights into xylem function, embolism susceptibility/repair in-vivo, and 3D plant anatomy. Fluorescence light microscopy will be used to investigate cell viability of cambium and parenchyma. Root hydraulic function and water transport pathways will be assessed using pressure probe methodology. Using a Scholander-type pressure chamber, the water potential method will be used to determine water status, stress thresholds, and plant dehydration stages. A mini-lysimeter platform will be established to control soil moisture and monitor plant water loss by transpiration. My research program provides opportunities for 3 PhD, 3 MSc, and 5 undergraduate students. My research team will be composed of diverse HQP where lab members can thrive as teammates. This will create a lab environment that supports the collaborative nature of science. I will ensure that everybody is treated fairly (equity) and feels part of the research team (inclusion) with equal opportunities for HQP to achieve scientific and professional goals.