How do mycorrhizal fungal traits influence ecosystem functioning?

菌根真菌特征如何影响生态系统功能？

• 批准号: RGPIN-2018-04169
• 负责人: Chagnon, PierreLuc
• 金额: $ 2.4万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=712760
• 关键词: How; do; mycorrhizal; fungal; traits

Mycorrhizal fungi (MF) associate with a majority of plants worldwide. They receive a significant portion of plant photosynthesis products, and in exchange they provide their host plants with an improved nutrition and tolerance to biotic and abiotic stresses. Given the large fraction of plant-derived carbon (C) that MF receive, they are highly likely to influence major steps of the C cycle. Many studies have indeed showed that MF can drastically influence C cycling through the alteration of litter decomposition or of plant primary productivity. However, different species of MF vary considerably in their traits, which may translate into different impacts on C cycling and ecosystem functioning more broadly. A trait-based framework is necessary to better predict how specific traits of MF influence ecosystem processes. This is the core of my research program. I focus on a specific group of MF, namely arbuscular mycorrhizal (AM) fungi, which are the most widespread group of MF. Using a variety of techniques, my research will contribute to answer the following questions: 1- Do AM fungi stabilize soil organic matter? We will assess, for example, the impact of AM fungi on the integration of plant-derived C within soil aggregates, and we will determine whether AM fungi negatively impact the decomposing activity of other soil fungi. 2- Do plants recruit AM fungi with specific traits? This work will significantly advance our understanding of AM fungal ecology, but also of plant ecology: it has been recognized by several authors that plant functional strategies not only integrate their own traits or characteristics, but also the traits of their microbial symbionts, such as AM fungi. We may thus expect trait correlations between plants and AM fungi. This would facilitate the integration of AM fungi in C cycling models, because plant traits are much easier to measure than fungal traits: it would be convenient to estimate the latter with the former. 3- What is the residence time of plant-derived C in AM fungal tissues? Given the large amount of C transferred to AM fungi, we must better understand its fate in the soil. If fast-growing AM fungi quickly replace their tissues and rapidly respire back plant-derived C to the atmosphere, then an increased allocation of C to AM fungi under global chance might not translate into an increased soil C storage, for example. We urgently need to characterize C turnover in AM fungal tissue, in this regard. Overall, my research program will offer a cohesive attempt to advance our understanding how AM fungi drive soil C cycling. Using a trait-based approach, the work presented here will also pave the way for studying functional strategies in AM fungi This, in itself, will be a major advancement of the field: plant ecology is an excellent example of how a trait-based approach can bring novel questions and insights in a scientific discipline. My aim is to promote a similar leap forward in AM fungai ecology.

菌根真菌 (MF) 与全世界大多数植物有关。它们接收很大一部分植物光合作用产物，作为交换，它们为宿主植物提供改善的营养和对生物和非生物胁迫的耐受性。鉴于 MF 接收的大部分植物源碳 (C)，它们极有可能影响碳循环的主要步骤。许多研究确实表明，MF 可以通过改变凋落物分解或植物初级生产力来极大地影响碳循环。然而，不同种类的 MF 其性状差异很大，这可能会转化为对碳循环和更广泛的生态系统功能的不同影响。为了更好地预测 MF 的具体特征如何影响生态系统过程，基于特征的框架是必要的。这是我的研究计划的核心。我重点关注 MF 的一个特定类群，即丛枝菌根 (AM) 真菌，这是最广泛分布的 MF 类群。我的研究将使用各种技术来回答以下问题： 1- AM 真菌可以稳定土壤有机质吗？例如，我们将评估 AM 真菌对植物来源的碳在土壤团聚体中整合的影响，并且我们将确定 AM 真菌是否会对其他土壤真菌的分解活性产生负面影响。 2- 植物是否会招募具有特定性状的 AM 真菌？这项工作将显着增进我们对 AM 真菌生态学以及植物生态学的理解：几位作者已经认识到，植物功能策略不仅整合了自身的性状或特征，还整合了其微生物共生体的特征，例如 AM真菌。因此，我们可以预期植物和 AM 真菌之间的性状相关性。这将有助于 AM 真菌在 C 循环模型中的整合，因为植物性状比真菌性状更容易测量：用前者来估计后者会很方便。 3- 植物来源的 C 在 AM 真菌组织中的停留时间是多少？鉴于大量碳转移到 AM 真菌中，我们必须更好地了解其在土壤中的命运。例如，如果快速生长的 AM 真菌迅速更换其组织，并迅速将植物来源的 C 呼吸回大气中，那么在全球机会下，增加 AM 真菌的 C 分配可能不会转化为土壤 C 储存的增加。在这方面，我们迫切需要表征 AM 真菌组织中的 C 转换。 总的来说，我的研究项目将提供一个有凝聚力的尝试，以加深我们对 AM 真菌如何驱动土壤碳循环的理解。使用基于性状的方法，这里介绍的工作也将为研究 AM 真菌的功能策略铺平道路，这本身就是该领域的重大进步：植物生态学是一个很好的例子，说明基于性状的方法如何发挥作用。可以带来科学学科中的新颖问题和见解。我的目标是促进 AM 真菌生态学的类似飞跃。