SP08: Microbiome and stress

SP08：微生物组和压力

• 批准号: 432651233
• 负责人: Professor Dr. Michael Schloter
• 金额: --
• 依托单位: Abteilung Vergleichende Mikrobiomanalysen (COMI)
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/432651233?language=en
• 关键词: SP08; Microbiome; stress

Drought stress drastically changes soil properties. The reduced water availability increases oxygen availability and solute concentration, reduces diffusion rates and changes physical soil properties. Such changes induce a cascade of consequences for microorganisms. For example, reduced root exudation causes nutrient shortage for heterotrophic rhizosphere bacteria, which then reduce their metabolic activity. That might affect nutrient return to the plant. How such cascades are altered by plant diversity-induced ecosystem stability, multifunctionality or drought severity is not known and will be a central question of the proposed research. Therefore, we will investigate how drought resistant bacteria change in diversity, relative abundance and activity along plant diversity and drought intensity gradients. We will use the Y-A-S framework to classify drought resistance traits in the categories related to yield improvement (Y), nutrient acquisition (A) and stress tolerance (S). That includes bacteria able to mineralize nitrogen and phosphorus (Y-A), produce exopolsyaccharides (A-S) or osmoprotective substances (S) or those being able to become dormant (S). We will address the following research questions: 1) How does plant diversity alter the relative abundance and diversity of bacteria exhibiting different drought-tolerance traits? 2) At which drought intensity do drought-resistant bacteria (S strategy) prevail over Y-A strategists and how is that mediated by plant diversity? 3) How do drought-tolerance traits of seed and soil-derived bacteria differ? To address these questions, we will participate in the Main Experiment and the DrY Experiment, to compare long-term plant diversity effects on drought-tolerant bacteria and short-term responses to different drought severity, respectively. Additionally, we will perform a MockCoMic Experiment, which tests synthetic consortia of drought-tolerant bacteria, which are isolated from seeds and rhizosphere soils of the Main Experiment, for their effectiveness to reduce drought stress of plants. We will test (1) the relevance of microbes with different drought-tolerance traits for the plant drought resistance and recovery and (2) if it matters whether the bacteria originate from the rhizosphere soil or the seed. With our proposal, we will particularly contribute to the overarching hypothesis of the Research Unit that plant diversity stabilizes ecosystem functioning and that the long-term pattern can be predicted based on short-term responses to drought. In addition, we will be able to link functional potentials to the diversity of contributing microbial groups. This enables us to estimate whether ecosystem stability is achieved by (1) an increase of bacteria with different drought tolerance traits (multifunctionality), for example, covering the whole Y-A-S triangle or (2) by a diversification of bacterial communities with the same trait, for example, more diverse polysaccharide producers or (3) both.

干旱胁迫极大地改变了土壤的性质。水有效性的降低增加了氧气的有效性和溶质浓度，降低了扩散速率，并改变了土壤的物理性质。这样的变化会给微生物带来一系列后果。例如，根分泌物的减少会导致异养根际细菌的营养短缺，从而降低它们的代谢活性。这可能会影响植物的养分回流。植物多样性诱导的生态系统稳定性、多功能或干旱严重程度如何改变这种级联反应尚不清楚，这将是拟议研究的一个中心问题。因此，我们将研究抗旱细菌的多样性、相对丰度和活性如何随植物多样性和干旱强度梯度的变化而变化。我们将使用Y-A-S框架将抗旱性状分类为与产量改良(Y)、养分获取(A)和抗逆性(S)相关的类别。这包括能够矿化氮和磷(Y-A)、产生胞外多糖(A-S)或渗透保护物质(S)的细菌或那些能够休眠的细菌(S)。我们将解决以下研究问题：1)植物多样性如何改变表现出不同耐旱性特征的细菌的相对丰度和多样性？2)抗旱性细菌(S策略)在什么干旱强度下战胜Y-A策略师，这是如何由植物多样性介导的？3)种子细菌和土壤来源细菌的耐旱性特征有何不同？为了解决这些问题，我们将参加主要实验和干旱实验，分别比较植物多样性对耐旱细菌的长期影响和对不同干旱程度的短期响应。此外，我们将进行一项MockCoMic实验，测试从主要实验的种子和根际土壤中分离出来的耐旱细菌的合成联合体，以确定它们对减少植物干旱胁迫的有效性。我们将测试(1)具有不同耐旱性特征的微生物与植物抗旱性和恢复的相关性，以及(2)细菌来自根际土壤还是种子是否重要。通过我们的提议，我们将特别有助于研究股的总体假设，即植物多样性稳定生态系统功能，并且可以根据对干旱的短期反应来预测长期模式。此外，我们将能够将功能潜力与贡献微生物群体的多样性联系起来。这使我们能够估计生态系统的稳定性是通过(1)具有不同耐旱性特征(多功能)的细菌的增加，例如，覆盖整个Y-A-S三角，还是(2)通过具有相同特征的细菌群落的多样化，例如，更多样化的多糖产生者，或(3)两者兼而有之。