A Systems Analysis of Plant Growth Promotion by the Rhizosphere Microbiome

根际微生物促进植物生长的系统分析

• 批准号: 1444571
• 负责人: Cynthia Weinig
• 金额: $ 324.41万
• 依托单位: University of Wyoming
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2023-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1444571&HistoricalAwards=false
• 关键词: Systems; Analysis; Plant; Growth; Promotion

Soil microbial communities represent a largely untapped source for yield improvement in crops. In comparison to plants grown without microbes in the soil, yields can be twice as great when plants are grown with their full complement of soil microbes. Microbes may improve plant growth by making soil nitrogen more available to plants. From the point of view of plant growth and eventual yield, nitrogen is important as it is a critical component of one enzyme, Rubisco, which takes carbon dioxide from the air and converts it to sugars for growth through the process of photosynthesis. To identify how microbes improve plant growth, the current research examines 1. how microbes modify soil chemistry, 2. what plant genes are selectively turned on in response to the presence of microbes, 3. how plant processes like photosynthesis respond to microbes, and 4. what the identity and functions are of the soil microbes. Connecting results from these four sets of data will reveal what it is that promotes plant growth, from the soil to the whole-plant level. This research also includes ways to predict plant growth and yield in response to soil microbes when different amounts of nitrogen are added to the soil, which should enable reduced use of fertilizers. The plant being studied is Brassica rapa, which is grown around the world as root (turnip), leaf (cabbage, pak choi), and oilseed (canola) crops; because of the diverse uses of this crop, results from this species are expected to apply to a wide range of other crops. Soil microbes are an important part of the ecosystem, and connect plants to the physical environment. While much is known about the plants in natural and agricultural settings, less is known about the distributions, types, and functions of beneficial soil microbes, and how they help crops cope with poor growing conditions such as drought or lack of nitrogen. The current research fills these knowledge gaps, and will provide recommendations on how to manage soils for beneficial microbes. Broader impacts to this work include development of guided tours within the Williams Conservatory, Geology Museum, and Berry Center for Biodiversity at the University of Wyoming as well as teaching modules related to the study of evolution and crop domestication. Soil microorganisms serve a range of ecosystem services that promote plant growth under stressful abiotic conditions, including nitrogen limitation. Yet, soil microbial communities represent a largely untapped source for yield improvement in crop species. Analyzing plant transcriptomic and physiological responses to taxonomically and functionally diverse soil microbiomes will provide insights as to the mechanisms by which microbes enhance plant growth. Further, Bayesian systems modeling of plant transcriptomic, hydraulic, and gas-exchange responses to the soil microbial environment can provide a predictive understanding of plant growth promotion by microbes under variable nitrogen amendments. When grown with an intact vs. reduced soil microbiome, crops of Brassica rapa upregulate gas-exchange and increase biomass accumulation up to two-fold, suggesting one physiological link between plant transcriptomic responses to soil microbes and eventual plant biomass accumulation. Because B. rapa is domesticated as root, leaf, and oilseed crops, mechanisms of growth promotion characterized in this species could translate to a range of other crops. Further, the microbiome associated with the rhizosphere of B. rapa is highly differentiated from that of bulk soils more distant from the roots, suggesting the species is an effective model for studying the assembly dynamics, identity, and function of beneficial plant-associated soil microbes. Using next-generation amplicon and metagenome sequencing of rhizosphere DNA in combination with plant genomic, transcriptomic, and physiological experiments, the research will characterize mechanisms of plant growth promotion by soil microbes and test predictive systems models. The research addresses the PGRP 2014 focal areas: to develop a genome-level link between genes and physiological functions in crop plants and to develop a genome to systems-level understanding of plant-environmental interactions, especially with respect to abiotic stress. Broader impacts to this work include development of guided tours and teaching modules related to crop domestication and improvement as well as development of management practices for beneficial microbes. Information on this project can be accessed at www.RhizoBiomics.org.

土壤微生物群落是提高作物产量的一个很大程度上尚未开发的资源。与在土壤中没有微生物的情况下种植的植物相比，在土壤中充分补充微生物的情况下种植的植物的产量可能是其两倍。微生物可以通过使土壤氮更容易被植物利用来促进植物生长。从植物生长和最终产量的角度来看，氮是重要的，因为它是一种酶的关键成分，Rubisco，它从空气中吸收二氧化碳，并通过光合作用将其转化为糖来生长。为了确定微生物是如何促进植物生长的，目前的研究检查了1。微生物如何改变土壤化学，2。2 .哪些植物基因会选择性地对微生物的存在做出反应？光合作用等植物过程如何对微生物作出反应；土壤微生物的特性和功能。将这四组数据的结果联系起来，将揭示是什么促进了植物的生长，从土壤到整个植物的水平。这项研究还包括在向土壤中添加不同数量的氮时预测植物生长和产量对土壤微生物的响应的方法，这应该能够减少肥料的使用。正在研究的植物是油菜，它在世界各地作为根（萝卜），叶（卷心菜，小白菜）和油籽（油菜）作物种植；由于该作物的用途多样化，该物种的研究结果有望广泛应用于其他作物。土壤微生物是生态系统的重要组成部分，将植物与自然环境联系起来。虽然人们对自然和农业环境中的植物了解很多，但对有益土壤微生物的分布、类型和功能，以及它们如何帮助作物应对干旱或缺氮等恶劣生长条件的了解却很少。目前的研究填补了这些知识空白，并将为如何管理有益微生物的土壤提供建议。对这项工作的更广泛的影响包括在威廉姆斯温室、地质博物馆和怀俄明大学贝瑞生物多样性中心开展导游活动，以及与进化和作物驯化研究相关的教学模块。土壤微生物提供一系列生态系统服务，促进植物在非生物胁迫条件下的生长，包括氮限制。然而，土壤微生物群落代表了作物品种产量提高的一个很大程度上未开发的来源。分析植物转录组学和生理反应对分类和功能多样化的土壤微生物组将为微生物促进植物生长的机制提供见解。此外，植物对土壤微生物环境的转录组学、水力和气体交换响应的贝叶斯系统建模可以为微生物在可变氮修正下促进植物生长提供预测性理解。当生长在完整的土壤微生物组和减少的土壤微生物组中，油菜作物上调气体交换和增加生物量积累高达两倍，这表明植物对土壤微生物的转录组反应与最终的植物生物量积累之间存在生理联系。由于rapa被驯化为根、叶和油料作物，该物种的生长促进机制可以转化为一系列其他作物。此外，与根际相关的微生物组与远离根的块状土壤微生物组高度分化，表明该物种是研究有益植物相关土壤微生物组装动力学，身份和功能的有效模型。利用新一代根际DNA扩增子和宏基因组测序，结合植物基因组学、转录组学和生理学实验，研究将表征土壤微生物促进植物生长的机制，并测试预测系统模型。该研究解决了PGRP 2014的重点领域：在作物植物中建立基因与生理功能之间的基因组水平联系，并在系统水平上建立植物与环境相互作用的基因组理解，特别是在非生物胁迫方面。对这项工作的更广泛影响包括开发与作物驯化和改良有关的导游和教学模块，以及开发有益微生物的管理实践。有关该项目的信息可访问www.RhizoBiomics.org。