Identifying the role of nodule endophytes in shaping nitrogen fixation effectiveness

确定根瘤内生菌在塑造固氮效果中的作用

• 批准号: 401830362
• 负责人: Professorin Dr. Macarena Marin
• 金额: --
• 依托单位: Département de biologie moléculaire végétale
• 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/401830362?language=en
• 关键词: Identifying; role; nodule; endophytes; shaping

Ineffective nodules are common in agricultural fields and constitute a limitation to the widespread use of biological nitrogen fixation in agriculture. What makes a nodule effective is the product of multiple factors, from the inherent capacity of rhizobia to fix nitrogen, to their compatibility with the host. How other root associated microbes impact nodule function has not been thoroughly investigated. In the first funding period we have shown that i) although Lotus nodules from different species and soil inoculums are dominated by Rhizobiales bacteria, the diversity and exact composition can vary greatly, ii) nodule composition largely depends on the inoculum, but the host genotype and health status also contribute, iii) L. burttii is more promiscuous than other Lotus plants, which can lead to the formation of ineffective nodules, iv) healthy L. burttii nodules are enriched in Pseudomonas, and v) co-isolated nodule endophytes promote growth in a host specific manner. In the second funding period we aim to elucidate how nodule endophytes impact nodule function through interactions with rhizobia and the host. To investigate this, we will apply a reductionist approach based on the reconstruction of synthetic microbial communities in gnotobiotic systems. In an interdisciplinary study including microbiology, computational biology and genetics we will i) identify and characterise nodule endophytes promoting formation of effective nodules and ii) find the genetic determinants underlaying host specific growth promotion by nodule endophytes. This interdisciplinary and collaborative project will help us understand the formation of effective nodules so in the future we can improve agricultural practices to avoid the establishment of ineffective root nodule symbioses.

无效结核在农田中很常见，限制了生物固氮在农业中的广泛应用。使根瘤有效的是多种因素的产物，从根瘤菌固有的固氮能力到它们与宿主的相容性。其他根相关微生物如何影响根瘤功能尚未得到彻底研究。在第一个资助期，我们已经表明，i）虽然来自不同物种和土壤接种物的莲花根瘤主要由根瘤菌目细菌，但多样性和确切组成可能差异很大，ii）根瘤组成在很大程度上取决于接种物，但宿主基因型和健康状况也有影响，iii）L.与其它莲属植物相比，burttii的混杂性更大，这会导致无效根瘤的形成;伯蒂根瘤富含假单胞菌，和v）共分离的根瘤内生菌以宿主特异性方式促进生长。在第二个资助期，我们的目标是阐明根瘤内生菌如何通过与根瘤菌和宿主的相互作用影响根瘤功能。为了研究这一点，我们将应用还原论的方法，基于在gnotobiotic系统中的合成微生物群落的重建。在包括微生物学、计算生物学和遗传学在内的跨学科研究中，我们将i）鉴定和鉴定促进有效结节形成的结节内生菌，ii）发现结节内生菌促进宿主特异性生长的遗传决定因素。这个跨学科的合作项目将帮助我们了解有效根瘤的形成，以便在未来我们可以改进农业实践，以避免建立无效的根瘤共生体。