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

植物的根部被数十亿种叫做细菌的微生物所包围。 这些细菌帮助植物获得营养和生长。 由于细菌的重要性，许多人对开发含有细菌的肥料感兴趣，以帮助植物更好地生长。 然而，很明显，虽然一些细菌，当添加到生长的植物，可以帮助他们在人工实验室条件下生长，几乎没有任何细菌可以帮助植物生长时，在现实条件下应用。 我们想知道为什么有些细菌能够帮助植物生长，而有些细菌不能。 为此，我们将研究促进生长的细菌所具有的基因，并确定这些基因是否可以将非促进生长的细菌转化为促进生长的细菌。 这项工作将在玉米中进行，并将培养一名研究生。有益微生物可以大大提高作物的表现，激励他们作为种子接种剂的使用。然而，外源微生物往往在该领域中被淘汰，这限制了它们的效用，并揭示了我们对根定殖的理解存在根本性差距。这一提议的基本原理是，对根部殖民最重要的基因在很大程度上是未知的。最近的工作，利用比较基因组学和敲除突变体提供了第一次深入了解参与根定殖的基因。然而，殖民化的全貌必须包括如何加强殖民化，目前还没有这种理解。由于根定殖是多方面的（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定殖。为了解析这种复杂性，我们将使用功能宏基因组学方法来筛选在三种不同营养条件下赋予改进的定殖玉米的基因。因此，这项工作将促进我们对根系定植的理解，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NSF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.