PUSHING THROUGH HARD TIMES: uncovering how roots sense soil compaction

粮食安全是一个重大的全球问题。表土是最宝贵的自然资本资产，提供了近95%的粮食。随着预计到2050年人口将达到90亿，人们对表土的紧迫感正在增强。压实会阻碍土壤过滤水分、吸收碳以及保留水分和养分以支持作物生长的能力。作物有效吸收水分和养分的能力有赖于其根系充分开发可用的土壤。使用重型农业设备、农场交通强度和过度放牧会导致土壤压实。例如，自1966年以来，农场使用的车辆的平均重量大约增加了两倍，最大轮重增加了六倍。土壤压实可使作物减产高达60%。因此，发展耐压实作物具有重要意义。尽管作物根系在全球农学上的重要性与日俱增，但人们对作物根系对土壤压实的反应知之甚少。我的BBSRC发现奖学金研究作物根系对土壤压实的反应，然后利用这一知识开发具有更强渗透能力的作物。我的项目最初试图填补根部之间的空白，感知土壤的紧实度，然后改变它们的生长和根尖的形状。为了帮助我的研究，我已经确定了植物信号和基因，如乙烯和EIN2，它们对这一过程很重要。还将采用几种有希望的方法，包括修改根部以降低对乙烯的敏感性。从我的研究中获得的知识将提供关于控制根对土壤压实反应的关键基因和过程的新信息，帮助育种者设计新的方法来操纵根的生长，以提高作物的资源捕获和产量。开发耐土壤压实的未来作物可以帮助它们的根更深地觅食水分，以帮助缓解干旱胁迫(坚硬的土壤很难渗透)，减少洪水(压实的土壤通过限制地表的水分吸收而增加洪水的风险)，氮素胁迫(因为这种养分在土壤中淋溶得更深)，还可以在土壤中捕获更多的碳。我的奖学金项目将在诺丁汉大学的植物科学中进行。该大学拥有一支世界领先的多学科研究团队，由来自数学、植物、作物、土壤和计算机科学的专家组成，他们都致力于揭开植物隐藏的那一半。为了实现这一目标，这些研究人员创建了霍斯菲尔德设施，该设施拥有最先进的微CT扫描仪和其他先进的成像平台。我还将受益于东道主Malcolm Bennett教授和同事土壤科学家Sacha Mooney教授以及作物科学家Sean Mayes博士、Rahul Bhosale博士和Darren Wells博士的无与伦比的支持。我的项目还涉及到国际和英国的合作者，其中包括瑞典的专家(Karin Ljung教授，激素分析)，中国(张大平教授，提供水稻资源和专业知识)和Rothamsted Research(Steve Thomas博士和Richard Whalley博士，小麦遗传学和土壤压实专业知识)。

Food security represents a major global issue. Topsoil, the most precious "natural capital assets", provides nearly 95% of food. The sense of urgency over topsoil is growing as the population is projected to reach 9 billion by 2050. Compaction hampers soil's ability to filter water, absorb carbon and retain water and nutrient to support the crop plants. The ability of a crop to efficiently absorb water and nutrients relies on its root system to fully explore soil available. Use of heavy farming equipment, intensity of farm traffic and overgrazing lead to soil compaction. For example, the average weight of vehicles used on farms has approximately tripled since 1966 and maximum wheel loads have risen by a factor of six. Soil compaction can reduce crop yields by as much as 60%. Therefore, developing compaction resistant crops is of paramount importance. Despite its increasing global agronomic importance, little is known about how crop roots may respond to soil compaction. My BBSRC Discovery Fellowship investigates how crop roots respond to soil compaction and then use this knowledge to develop crops with improved penetration ability. My project initially attempts to 'fill in the gaps' between roots sensing soil compaction and then altering their growth and shape of their root tips. To help my studies, I have already identified plant signals and genes such as ethylene and EIN2 that are important for this process. Several promising approaches will also be conducted including modifying roots to be less sensitive to ethylene. The knowledge gained from my fellowship will provide new information about the key genes and processes controlling root responses to soil compaction, helping breeders design novel approaches to manipulate root growth to enhance resource capture and yield in crops. Developing future crops resistant to soil compaction can help their roots forage deeper for water to help mitigate drought stress (hard soil which is tough to penetrate), reduce flooding (compacted soil poses increased risk of flooding by restricting the water absorption from the surface), nitrogen stress (as this nutrient leach deeper in soil) and also capture more carbon in the soil.My fellowship project will be undertaken in Plant Sciences at the University of Nottingham. The University hosts a world leading multidisciplinary team of researchers composed of experts from Maths, Plant, Crop, Soil and Computer Sciences, all dedicated to 'uncover' the hidden half of plants. To achieve this, these researchers have created the Hounsfield Facility which hosts state-of-the-art microCT scanners and other advanced imaging platforms. I will also benefit from the unparalleled support of my host Prof. Malcolm Bennett and colleagues Soil Scientist Prof. Sacha Mooney and Crop Scientists Dr. Sean Mayes, Dr. Rahul Bhosale and Dr. Darren Wells. My project also involves international and UK collaborators which include experts in Sweden (Prof. Karin Ljung for hormone analysis), China (Prof. Dabing Zhang providing rice resources and expertise) and Rothamsted Research (Dr. Steve Thomas and Dr. Richard Whalley, wheat genetics and soil compaction expertise).