Mechanisms of basidiomycete yeast function in complex leaf microbial communities

担子菌酵母在复杂叶微生物群落中的功能机制

• 批准号: 401857633
• 负责人: Professor Dr. Gunther Döhlemann
• 金额: --
• 依托单位: Lehrstuhl für Mikrobielle Interaktionen im Pflanzlichen Ökosystem
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/401857633?language=en
• 关键词: Mechanisms; basidiomycete; yeast; function; complex

Plant-colonizing microbes evolved complex microbial interactions, in which fungi and oomycetes are major determinants of diversity and abundance of plant-associated bacteria. Since fungi and oomycetes compete for the plant niche, it is key to understand how these organism groups interact in the leaf phyllosphere. A key hub microbe in the leaf phyllosphere is the oomycete Albugo laibachii. In our experiments we identified the basidiomycete yeast Moesziomyces bullatus ex Albugo on Arabidopsis (MbA) as an antagonist of A. laibachii. Gene deletion guided by transcriptomics identified a Glucoside hydrolase-family 25 (GH25) of MbA being required for inhibition of A. laibachii. Enzyme assays showed a lysozyme activity of the GH25 protein, which effectively inhibited A. laibachii infection when applied on Arabidopsis. Phylogenetic analyses of GH25 revealed two main clades throughout the Basidiomycota. However, several basidiomycetes do not contain orthologs of GH25, including the Cystofilobasidiales, which we identified as core taxa with a maximum occurrence in the A. thaliana phyllosphere at the peak of community stability. Cystofilobasidium inhibits A. laibachii in a community context, suggesting a GH25-independent mechanism of antagonism. We will study GH25 mediated microbial antagonism and its role in community assembly. Complementary, we will explore GH25-independent mechanisms in diverse basidiomycete yeasts. We will test functional conservation of GH25 as an inhibitor of different oomycetes, as well as its effects on selected plant associated fungi and bacteria. These one-to-one interactions will guide us to investigate the effects of MbA GH25 mutant and overexpression lines in a community context. We hypothesize that absence of GH25 de-stabilizes the community, resulting in increased sample-to-sample variations.To study the effects of GH25 dependent and independent repression of A. laibachii on microbial communities, we will express MbA orthologs from a broad range of basidiomycetes in the MbA GH25 deletion mutant. In parallel, we will infer the mechanism of GH25 independent suppression of A. laibachii by a range of Cystofilobasidium isolates. We will analyze differences and communalities of MbA versus Cystofilobasidum function on bacterial communities in presence/absence of A. laibachii. We hypothesize that under varying conditions, presence/absence of GH25 affects the yeast’s fitness, resulting in genomic signatures we will infer by whole genome analyses of Cystofilobasidium isolates. To compile all data and test our hypotheses on community assembly, we will develop computational pipelines to predict microbial host ranges and lifestyles, to identify communal sub-structures, and how they are affected by presence/absence of key functional genes such as the GH25. Thus, our proposed project is a combinatorial approach to elucidate microbial community behavior and stability with a functional molecular analysis of direct microbial interactions.

植物定殖微生物进化出复杂的微生物相互作用，其中真菌和卵菌是植物相关细菌多样性和丰度的主要决定因素。由于真菌和卵菌竞争植物生态位，这是关键，以了解这些生物群体如何在叶际相互作用。叶际中的一个关键枢纽微生物是卵菌白蛋白。在我们的实验中，我们确定了担子菌酵母Moesziomyces bullatus ex Albugo on Arabidopsis（MbA）作为A.莱巴奇。转录组学指导的基因缺失鉴定出MbA的糖苷水解酶家族25（GH 25）是抑制A.莱巴奇。酶活性测定表明，GH 25蛋白具有溶菌酶活性，能有效抑制A.当应用于拟南芥时，laibachii感染。GH 25的系统发育分析揭示了整个担子菌门的两个主要分支。然而，一些担子菌不包含GH 25的直系同源物，包括我们鉴定为核心分类群的囊丝担子目，其在A.在群落稳定性的高峰期，Cystofilobasidium抑制A. laibachii在社区背景下，这表明一个GH 25独立的拮抗机制。我们将研究GH 25介导的微生物拮抗作用及其在群落组装中的作用。作为补充，我们将探索GH 25在不同的担子菌酵母中的独立机制。我们将测试GH 25作为不同卵菌的抑制剂的功能保护，以及其对选定的植物相关真菌和细菌的影响。这些一对一的相互作用将指导我们在社区背景下研究MbA GH 25突变体和过表达系的影响。我们假设，缺乏GH 25使群落不稳定，导致样品间变异增加。为了在微生物群落上表达莱氏菌，我们将在MbA GH 25缺失突变体中表达来自广泛的担子菌的MbA直系同源物。同时，我们将推测GH 25独立抑制A.莱巴氏菌的一系列囊丝担孢子菌分离物。我们将分析在存在/不存在A的情况下MbA与Cystofilobasidum对细菌群落功能的差异和共同性。莱巴奇。我们假设，在不同的条件下，存在/不存在的GH 25影响酵母的健身，导致基因组签名，我们将推断通过全基因组分析Cystofilobasidium分离株。为了编译所有数据并测试我们对社区组装的假设，我们将开发计算管道来预测微生物宿主范围和生活方式，识别公共子结构，以及它们如何受到存在/不存在关键功能基因（如GH 25）的影响。因此，我们提出的项目是一个组合的方法来阐明微生物群落的行为和稳定性与直接微生物相互作用的功能分子分析。