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

由于持续的气候变化，加拿大的农业食品部门正面临着干旱带来的前所未有的挑战。2001年至2002年的全国干旱导致农业生产损失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。干旱条件下作物的生产性能取决于根、茎和叶水平上各过程的成功协调。这包括有效的气孔调节和根下沉化，分别避免过多的水分流失到大气和土壤中。干旱导致的死亡主要与木质部水力衰竭有关，因为气体栓塞阻碍了水分从根到叶的输送。了解干旱引起的生理和解剖事件的顺序将有助于(a)选择抗旱性更好的作物基因型和(b)发展可持续灌溉做法。我最近对多年生木本作物干旱胁迫响应的研究，导致了一种新的方法来预测叶片水平的过程特异性胁迫阈值，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力驱动的。我的研究项目的长期目标是阐明作物对水的需求，通过节水来促进可持续农业。在我的项目中，短期目标是(a)确定与气孔关闭和膨胀损失相关的压力阈值，(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水分吸收的动态变化。我将结合使用传统和先进的测量工具来阐明干旱下的作物表现。加拿大光源的x射线计算机微断层扫描将为木质部功能、体内栓塞易感性/修复和3D植物解剖提供前所未有的见解。利用荧光显微镜观察形成层和薄壁组织的细胞活力。根水力功能和水运输途径将评估使用压力探针的方法。利用肖兰德式压力室，水势法将用于确定水分状态、压力阈值和植物脱水阶段。建立微型蒸渗仪平台，控制土壤湿度，监测植物蒸腾水分流失。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合作本质的实验室环境。我将确保每个人都被公平对待（公平），并感到自己是研究团队的一员（包容），并有平等的机会让HQP实现科学和专业目标。

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.