Short-circuiting the terrestrial phosphorus cycle: symbiotic control of organic phosphorus mineralisation and uptake

缩短陆地磷循环：有机磷矿化和吸收的共生控制

• 批准号: NE/W000350/1
• 负责人: David Johnson
• 金额: $ 84.38万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FW000350%2F1
• 关键词: Short; circuiting; terrestrial; phosphorus; cycle

Plants need to take up phosphorus from soil to grow. To do this, it has been assumed for decades that plants can only access mineral (inorganic) forms of phosphorus from soil, and indeed these mineral forms are the basis of most fertilisers. Inorganic phosphorus is largely created in soil through microbial conversion of organic forms, which usually comprise the main pool of phosphorus in soils. This so-called 'mineralisation' process is also assumed to be largely undertaken by free-living soil microorganisms. However, our recent discoveries from NERC-funded research suggest that trees that form intimate relationships with soil fungi (called ectomycorrhizal fungi) on their roots can acquire phosphorus from both organic and inorganic forms. These findings raise questions of global importance that challenge our entrenched understanding of the terrestrial phosphorus cycle: 1. Can plants, via their symbiotic root-associated ectomycorrhizal fungi, acquire organic forms of phosphorus directly, i.e. keeping the chemical intact, thus 'short-circuiting' the conventional mineralisation pathway? 2. Can ectomycorrhizal fungi accelerate mineralisation of organic phosphorus? 3. What happens when the demand for phosphorus increases, for example because of nitrogen pollution from the atmosphere? The potential to acquire organic forms of phosphorus would give plants that form associations with ectomycorrhizal fungi access to otherwise inaccessible pools of nutrients in soil. These mechanisms of phosphorus acquisition may also provide explanations as to why plants that form different types of associations on their roots can coexist. The findings may also explain how plant communities may respond to increasing phosphorus limitation of ecosystems that is occurring as a consequence of atmospheric nitrogen pollution. We are now able to address these questions through recent developments in the synthesis of isotopically-labelled organic forms of phosphorus. In this proposal, we will therefore synthesise a suite of ecologically-relevant organic forms of phosphorus that have a radioactive tag attached to them to enable us to visualise and measure the movement and breakdown of these chemicals. We will test the hypotheses that i) ectomycorrhizal fungi acquire organic forms directly and transfer these nutrients to plants, ii) ectomycorrhizal plants acquire phosphorus from organic forms by accelerating their mineralisation, and iii) these processes are stimulated in systems that are strongly limited by phosphorus as a consequence of sustained inputs of nitrogen. Our work will have major impact on understanding biogeochemical cycles in woodlands and forests that are dominated by ectomycorrhizal trees, and how niche partitioning of phosphorus may explain coexistence of mycorrhizal types.

植物需要从土壤中占据磷。为此，数十年来一直假定植物只能从土壤中获取矿物（无机）形式的磷，实际上这些矿物质形式是大多数肥料的基础。无机磷在土壤中通过微生物的微生物转化在土壤中的主要产生，通常构成土壤中磷的主要库。也认为这种所谓的“矿化”过程在很大程度上是由自由生活的土壤微生物进行的。但是，我们最近从NERC资助的研究中发现的是，在其根部与土壤真菌（称为外生霉素真菌）形成亲密关系的树木可以从有机和无机形式中获取磷。这些发现引发了全球重要性的问题，这些问题挑战了我们对陆地磷周期的根深蒂固的理解：1。可以通过其共生根相关的肠道外菌骨真菌来植物，直接获得磷的有机形式，即保持化学物质完整，从而“近距离循环”传统矿物质式矿物质？ 2。外生菌根真菌可以加速有机磷的矿化吗？ 3。当磷的需求增加时，会发生什么，例如，由于大气中的氮污染？获取有机形式的磷的潜力将使植物与外生菌的真菌相连，从而获得土壤中其他营养池的接触池。这些磷获取的机制也可能提供解释，说明为什么在其根部形成不同类型的关联的植物会共存。这些发现还可以解释植物群落如何应对由于大气氮污染而发生的生态系统磷限制的增加。现在，我们能够通过在同位素标记的有机形式的磷的最新发展中解决这些问题。因此，在此提案中，我们将综合一套与生态相关的有机形式的磷，这些形式具有放射性标签，以使我们能够可视化和测量这些化学物质的运动和分解。我们将检验以下假设：i）i骨菌骨真菌直接获得有机形式并将这些养分转移到植物中，ii）外生菌骨植物通过加速矿化而从有机形式中获取磷，并且iiii）这些过程在受磷酸盐的磷酸群中受到严格限制的系统而受到维持的NIT niT niT niT的限制。我们的工作将对理解由外生菌树主导的林地和森林中的生物地球化学循环产生重大影响，以及磷的小裂分配如何解释菌根类型的共存。

项目成果

Crystal Structure and Enzymology of Solanum tuberosum Inositol Tris/Tetrakisphosphate Kinase 1 (StITPK1).

• DOI: 10.1021/acs.biochem.3c00404
• 发表时间: 2024-01-02
• 期刊: BIOCHEMISTRY
• 影响因子: 2.9
• 作者: Whitfield, Hayley L.;Rodriguez, Raquel Faba;Shipton, Megan L.;Li, Arthur W. H.;Riley, Andrew M.;Potter, Barry V. L.;Hemmings, Andrew M.;Brearley, Charles A.
• 通讯作者: Brearley, Charles A.

Characterisation of a soil MINPP phytase with remarkable long-term stability and activity from Acinetobacter sp.

• DOI: 10.1371/journal.pone.0272015
• 发表时间: 2022
• 期刊: PLOS ONE
• 影响因子: 3.7
• 作者: Rix, Gregory D.;Sprigg, Colleen;Whitfield, Hayley;Hemmings, Andrew M.;Todd, Jonathan D.;Brearley, Charles A.
• 通讯作者: Brearley, Charles A.