EAGER: High-throughput discovery of microbial genes conferring improved root colonization.

植物的根被数十亿被称为细菌的微生物所包围。这些细菌帮助植物获取营养并生长。由于细菌的重要性，许多人对开发含有细菌的肥料来帮助植物更好地生长感兴趣。然而，已经很清楚的是，当一些细菌被添加到正在生长的植物中时，可以帮助它们在人工的实验室条件下生长，而在实际条件下，几乎没有任何细菌可以帮助植物生长。我们想知道为什么有些细菌能帮助植物生长，而有些细菌不能。为此，我们将研究促生长细菌所具有的基因，并确定这些基因是否可以将非促生长细菌转化为促生长细菌。这项工作将在玉米中进行，并将培养一名研究生。有益微生物可以极大地提高作物的生长性能，促使它们作为种子接种剂的使用。然而，外源微生物在该领域往往处于竞争优势，这限制了它们的效用，并揭示了我们对根定殖的理解的根本差距。这一建议的基本原理是，对根系定植最重要的基因在很大程度上是未知的。最近利用比较基因组学和基因敲除突变体的研究，首次深入了解了参与根定植的基因。然而，一个完整的殖民化图景必须包括如何加强它，目前还没有这样的理解。由于根的定植是多方面的（包括与其他微生物、宿主和非生物土壤条件的相互作用），因此预计微生物和植物基因的多样性将影响根的定植。为了分析这种复杂性，我们将使用功能宏基因组学方法筛选在三种不同营养条件下赋予改良定植玉米的基因。因此，这项工作将促进我们对根定植的理解，并提高我们识别长期发挥有益作用的微生物的能力。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Plant roots are surrounded by billions of microscopic organisms called bacteria. These bacteria help the plant obtain nutrients and grow. Because of how important bacteria are, many people are interested in developing fertilizers containing bacteria to help plants grow better. However, it has become clear that while some bacteria, when added to a growing plant, can help them grow under artificial laboratory conditions, hardly any bacteria can help a plant grow when applied under realistic conditions. We would like to understand why some bacteria are able to help plants grow, while some bacteria cannot. To do this, we will study the genes that growth-promoting bacteria have, and determine whether these genes can convert a non-growth-promoting bacteria into a growth-promoting one. This work will be performed in corn, and will train one graduate student.Beneficial microorganisms can greatly improve crop plant performance, motivating their use as seed inoculants. However, exogenous microbes are often outcompeted in the field, which limits their utility and reveals fundamental gaps in our understanding of root colonization. The rationale for this proposal is that the genes that are most important for colonizing the root are largely unknown. Recent work using comparative genomics and knockout mutants has provided the first insights into the genes involved in root colonization. However, a complete picture of colonization must include how to enhance it, an understanding that is not currently available. Since root colonization is multifaceted (encompassing interactions with other microbes, the host, and abiotic soil conditions) it is expected that a diversity of microbial and plant genes will impact root colonization. To parse this complexity, we will use a functional metagenomics approach to screen for genes conferring improved colonization maize under three different nutrient conditions. This work will therefore advance our understanding of root colonization and our ability to identify microbes that exert beneficial effects for prolonged periods.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.