Improving Crop Stress Tolerance under Climate Change

到2050年，全球粮食需求将需要主要粮食作物目前的产量翻一番，才能养活不断增长的人口。干旱和高温对满足这一需求构成了重大挑战，因为它们大大减少了植物的生长、存活和作物产量。预计气候变化将进一步加剧这一挑战，使大田作物更加暴露在极端温度下，干旱的严重程度和频率也会增加。因此，迫切需要调整我们的栽培实践，开发最适合不断变化的环境的抗逆作物品种。提高作物对CO2浓度升高下干旱和高温胁迫的适应性是最重要和最具挑战性的目标之一。这一挑战可以通过在生理、生化和分子水平上鉴定与胁迫相关的性状并将其应用于新的作物品种来应对。然而，缺乏关于植物如何检测和应对干旱和高温胁迫的数据，以及评估许多作物胚芽的高通量技术的有限性，构成了主要的研究空白。因此，我的研究计划有两个广泛的科学目标。一是研究CO2浓度升高条件下植物耐旱和耐高温的生理、生化和分子机制。阐明这些机制将有助于确定关键性状，这些性状为培育新品种提供了相当大的潜力，这些新品种可以在不断变化的环境条件下维持甚至提高作物产量。该研究计划的第二个广泛的科学目标是开发遥感方法，用于叶片生理和生化性状的高通量表型分析，以快速准确地筛选大型和多样化的作物种质。我们最近已经确定，马铃薯基因型的变化，以耐受干旱胁迫与光合调节的差异。在拟议的研究中，我们将结合联合收割机气体交换和荧光与生化和分子分析，包括代谢物测定和基因表达谱，以阐明光合调节和耐旱性在环境CO2的精确机制。 叶片的反射光谱主要受其生理活性和生化组成的影响。因此，在所提出的研究中，我们将检验这样的假设，即干旱相关的生理和生化性状的变化反映在马铃薯基因型之间反射模式的差异上。这些信息将被用来开发新的光谱指数，可以最好地预测叶片的生理活性和生物化学。随后，我们将研究干旱和高温之间的相互作用如何影响光合作用，基因表达谱和反射模式在CO2浓度升高。 研究提案的另一个重要总体目标是指导和培训两名研究生和五名本科生。

Global food demand will require double the current yield of major food crops to feed the increasing population by 2050. Drought and high temperature pose a major challenge to meet this demand by substantially curtailing plant growth, survival and crop yield. Climate change is expected to further aggravate this challenge by intensifying the exposure of field crops to extreme temperatures, and increased drought severity and frequency. It is, therefore, urgently necessary to adapt our cultivation practices and develop stress tolerant crop cultivars best suited to the changing environment. Improving crop adaptability to drought and heat stress under increasing CO2 is one of the most important and challenging targets. This challenge can be approached through the identification of stress-related traits at the physiological, biochemical and molecular levels and their deployment in new crop cultivars. Yet the lack of data on how plants detect and respond to drought and heat stress, as well as limited availability of high-throughput techniques to assess many crop germplasms, constitute major research gaps. Thus, my research program has two broad scientific goals. The first is to investigate the physiological, biochemical and molecular mechanisms that govern plant tolerance to drought and high temperature under increasing CO2. Elucidation of such mechanisms will help identify key traits that provide considerable potential for breeding new cultivars that can sustain or even enhance crop yield under changing environmental conditions. The second broad scientific goal of the research program is to develop remote sensing approaches for high-throughput phenotyping of leaf physiological and biochemical traits for rapid and precise screening of a large and diverse crop germplasms. We have recently established that variations in potato genotypes to tolerate drought stress is associated with differences in photosynthetic adjustment. In the proposed research, we will combine gas exchange and fluorescence with biochemical and molecular analyses including metabolite assays and gene expression profiling to elucidate the precise mechanism of photosynthetic adjustment and drought tolerance at ambient CO2. Leaf reflectance pattern is primarily governed by its physiological activity and biochemical composition. Thus, in the proposed research, we will test the hypothesis that the variations in drought- related physiological and biochemical traits are mirrored by differences in reflectance patterns across potato genotypes. This information will be used to develop new spectral indices that can best predict the leaf physiological activity and biochemistry. Subsequently, we will examine how the interactions between drought and high temperature impact photosynthesis, gene expression profiles and reflectance patterns at elevated CO2. Another important overall goal of the research proposal is the mentorship and training of two graduate students and five undergraduate students.