Functional differentiation of arbuscular mycorrhizal fungi in top- vs. subsoil: do subsoils harbor nutrient acquisition traits supportive for sustainable agriculture?

表土与底土中丛枝菌根真菌的功能差异：底土是否具有支持可持续农业的养分获取特征？

• 批准号: 521884211
• 负责人: Dr. Svenja Stock
• 金额: --
• 依托单位: Arbeitsgruppe Geo-Biosphären Wechselwirkungen
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/521884211?language=en
• 关键词: Functional; differentiation; arbuscular; mycorrhizal; fungi

Monocropping and inefficient resource utilization, accompanied by soil degradation and soil biodiversity loss in conventionally managed agricultural systems, pose challenges to stable food production. Sustainable strategies are needed to ensure food production without (further) compromising the health and functionality of agroecosystems. Arbuscular mycorrhizal fungi (AMF) are the most widespread symbionts among crops and have received increasing attention for their beneficial effects on plant nutrition, promotion of crop resistance, and improving soil stability. Most studies on the benefits of AMF for crop production, however, have focused on AMF in the topsoil, i.e., the thin plow layer in conventionally managed systems. The potential of AMF in agricultural subsoils (i.e., the mineral soil below the plow layer) for sustainable agriculture is rarely studied. While the abundance of AMF decreases from top- to subsoil, it has been shown that subsoils can host a unique set of AMF taxa that are assumed to differ in traits and functionality from topsoil AMF. The main objective of this project is the functional differentiation of top- and subsoil AMF communities with respect to their nutrient acquisition and allocation strategies. The project aims to answer the question of (i) whether subsoils harbor AMF communities with functional traits that are distinct from, or even more diverse than, AMF communities in topsoil, and (ii) whether these traits can be beneficial for sustainable management. DNA amplicon sequencing and metatranscriptome analysis of AMF communities associated to plants of different plant functional groups will allow a first assessment of the functional diversity of subsoil AMF communities, based on the assumption of a trait-based partner selection between plants and fungi. For a further functional characterization, the uptake and transfer of readily available N and K by subsoil AMF communities is assessed using 15N-enriched compounds and trace elements that act as K analogs during nutrient uptake. The stimulation of N and P mobilization from organic matter by AMF subsoil communities is investigated using dual isotopic labeled (15N, 33P) organic matter. With 13CO2-pulse labeling, the carbon allocation of crop plants to different subsoil AMF communities will be analyzed. The project will provide insights into the potential of subsoils as reservoirs for functionally diverse AMF communities and their potential to improve nutrient utilization in agricultural systems. Thereby, the project will help to clarify whether an adequate subsoil management is suitable to promote functional diversity of AMF in agricultural systems, or even target specific functional traits, to help stabilize food production.

单一作物种植和资源利用效率低下，以及常规管理农业系统中的土壤退化和土壤生物多样性丧失，对稳定的粮食生产构成了挑战。需要采取可持续战略来确保粮食生产不会（进一步）损害农业生态系统的健康和功能。丛枝菌根真菌（AMF）是作物中最广泛的共生体，因其对植物营养、增强作物抗性和改善土壤稳定性的有益作用而受到越来越多的关注。然而，大多数关于 AMF 对作物生产的益处的研究都集中在表土中的 AMF，即传统管理系统中的薄耕层。 AMF 在农业底土（即耕作层以下的矿质土壤）中用于可持续农业的潜力很少被研究。虽然 AMF 的丰度从表土到下土逐渐减少，但研究表明，下土可以容纳一组独特的 AMF 类群，这些类群被认为在性状和功能上与表土 AMF 不同。该项目的主要目标是表层和地下 AMF 群落在养分获取和分配策略方面的功能分化。该项目旨在回答以下问题：(i) 底土中的 AMF 群落是否具有与表土中的 AMF 群落不同甚至更加多样化的功能特征，以及 (ii) 这些特征是否有利于可持续管理。与不同植物功能群的植物相关的 AMF 群落的 DNA 扩增子测序和元转录组分析将基于植物和真菌之间基于性状的伙伴选择的假设，首次评估底土 AMF 群落的功能多样性。为了进一步进行功能表征，使用富含 15N 的化合物和在养分吸收过程中充当钾类似物的微量元素来评估底土 AMF 群落对容易获得的氮和钾的吸收和转移。使用双同位素标记（15N，33P）有机物研究了 AMF 底土群落对有机物中 N 和 P 动员的刺激。通过 13CO2 脉冲标记，将分析作物植物对不同底土 AMF 群落的碳分配。该项目将深入了解底土作为功能多样的 AMF 群落的水库的潜力及其提高农业系统养分利用率的潜力。因此，该项目将有助于澄清适当的底土管理是否适合促进农业系统中 AMF 的功能多样性，甚至针对特定的功能性状，以帮助稳定粮食生产。