The tree phyllosphere microbiome - an overlooked and important sink for carbon monoxide?

树木叶际微生物群——一个被忽视的重要一氧化碳库？

• 批准号: NE/X001245/1
• 负责人: Hendrik Schaefer
• 金额: $ 82.23万
• 依托单位: University of Warwick
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FX001245%2F1
• 关键词: tree; phyllosphere; microbiome; overlooked; important

In this project, we will investigate whether microorganisms associated with the above ground parts of trees are important as degraders of the gas carbon monoxide. Carbon monoxide, CO, is a product of incomplete combustion processes and is known to most people as a potentially lethal gas and component of air pollution. However, it is also a naturally occurring trace gas that is produced by natural environmental processes which contribute to its background atmospheric concentration of just 50-150 parts per billion. Even at these trace levels in the atmosphere, at which CO is not toxic, this gas plays an important role because it affects the lifetime of other atmospheric gases. It is referred to as a short-lived climate forcer and an indirect greenhouse gas. This is due to it reacting with hydroxyl (OH) radicals which are important for reactions of a wide range of atmospheric trace gases, some of which contribute to the greenhouse effect such as methane and tropospheric ozone. Elevated levels of CO in the atmosphere therefore have an indirect impact on climate, by removing OH radicals which could otherwise react with methane and ozone, thereby increasing the lifetime and effect that these important greenhouse gases have. In addition, CO affects air quality and human health at higher concentrations.The ability of specific microorganisms to degrade CO has long been known, and previous studies have established that CO degrading microorganisms are present in soils and in the oceans. By degrading CO, these microorganisms contribute to the natural cycling of CO and either remove it from the atmosphere or prevent it from being emitted to the atmosphere from soils and seawater, thus contributing to regulating its natural low concentrations. We have recently shown that the above ground parts of trees are colonised by CO degrading microorganisms. At the global scale, the phyllosphere of trees is a vast habitat for microorganisms, microbial activities in the phyllosphere are therefore also of global importance. Microorganisms inhabiting the phyllosphere (primarily the leaves and stems) are in direct contact with the atmosphere and are therefore able to take up CO produced by photochemical reactions in live plant tissue or take it up from the surrounding air. Their CO degradation activity has not been shown previously. Only in our previous work on CO-degrading microorganisms associated with tree leaves has the potential of CO degradation been shown; these findings warrant further investigation because it means that a potentially major global removal mechanism for CO has not been recognised previously. Understanding this process is fundamentally important because it will allow to disentangle how CO-degrading microorganisms in the phyllosphere affect CO fluxes from vegetation. Identifying the diversity of phyllosphere CO-degrading microorganisms, understanding which of them are active, and how their activity is affected by environmental factors is vital to provide a better comprehension of how the CO-fluxes from vegetation are regulated and how they vary across temporal and spatial scales.In incubation experiments, we will be able to determine degradation of CO at environmental concentrations, and then identify and characterise these CO-degrading microorganisms using modern metagenomic and metatranscriptomics approaches which are based on the sequencing of the DNA and RNA of the phyllosphere microorganisms, respectively. The insights from our work will thus provide fundamental new insights into the global cycle of CO and contribute to a better understanding of how the composition of the atmosphere is affected by microbial activities. It will also allow us to examine how CO degrading microorganisms fundamentally affect atmospheric chemistry and CO emission from vegetation, a process that affects global climate.

在这个项目中，我们将研究与树木的地面部分相关的微生物作为一氧化碳碳的降解物重要。 CO碳一氧化碳是不完整燃烧过程的产物，大多数人被称为潜在的致命气体和空气污染的成分。但是，它也是一种天然存在的痕量气体，它是由自然环境过程产生的，其背景大气浓度仅为每十亿美元的零件50-150份。即使在CO无毒的大气中的这些痕量水平上，这种气体也起着重要作用，因为它会影响其他大气气体的寿命。它被称为短寿命的气候牙和间接温室气体。这是由于它与羟基（OH）自由基反应，这对于广泛的大气痕量气体的反应很重要，其中一些有助于温室效应，例如甲烷和对流层臭氧。因此，大气中的CO水平升高会通过去除可以与甲烷和臭氧反应的OH自由基来增加对气候的间接影响，从而增加了这些重要的温室气体所具有的寿命和影响。此外，CO会在较高浓度下影响空气质量和人类健康。特定的微生物对降解CO的能力已知已知，并且先前的研究已经确定，在土壤和海洋中存在CO降解微生物。通过降解CO，这些微生物有助于自然循环CO，要么将其从大气中取出，要么防止其从土壤和海水中散发到大气中，从而有助于调节其自然低浓度。我们最近表明，树木的地面部分是通过降解微生物殖民的。在全球范围内，树木的植物层是微生物的巨大栖息地，因此，植物层中的微生物活性也具有全球重要性。居住在植物层的微生物（主要是叶子和茎）与大气直接接触，因此能够在活植物组织中的光化学反应产生或从周围的空气中取出。他们的共同降解活性先前尚未显示。只有在我们以前关于与树叶相关的共降解微生物的工作中，才显示出降解的潜力。这些发现需要进一步的研究，因为这意味着以前尚未确认CO的潜在主要全球去除机制。理解这一过程在根本上很重要，因为它将允许解散植物圈中的微生物如何影响植被的CO通量。识别植物球的多样性共同降解微生物，了解它们中的哪个是活跃的，以及它们的活动如何受环境因素的影响，对于更好地理解了对植被中的共同提供的调节以及它们如何在时间和空间尺度上变化的培养型实验，我们将确定这些培养的​​集中度，我们将在环境方面的范围，我们将在环境中的表征，并确定它们的表征，并确定这些环境的融合，并在环境方面进行了融合，并在环境方面进行了融合，并在环境方面进行了融合，并在环境方面进行了融合，并在环境中进行了融合。使用现代宏基因组和元文字方法的微生物分别基于植物层微生物的DNA和RNA的测序。因此，我们工作的见解将为CO的全球周期提供基本的新见解，并有助于更好地理解大气组成如何受微生物活动的影响。它还将使我们能够研究微生物从根本上影响大气化学和植被的发射，这是影响全球气候的过程。