Genome-sequencing of the obligate symbiotic, Mycoplasma-related endobacteria of arbuscular mycorrhizal fungi to uncover their function and coevolution.

丛枝菌根真菌(AMF)是已有4亿年历史的陆地植物共生体，在其细胞质中寄生革兰氏阳性细菌，传统上被称为类细菌(BLOS)。最近，我们可以证明AMF-BLOS的16S rDNA序列(来自高度多样化的AMF谱系)都属于&gt；400我的老单系支系，属于Mollicuts纲。尽管不可培养的BLOS在AMF中肯定发挥着重要的，也许是细胞器样的作用，但它们的功能到目前为止还不清楚。在这个项目中，我们的目标是实现BLOS基因组的完整测序，以帮助创始人了解它们在重要的AM共生中的功能。在同一个AMF孢子中，BLO具有遗传多态。为了探索和注释它们的元基因组和个体基因组序列，我们将使用两个定义良好的AMF分离株，并结合元基因组学、单细胞分选、全基因组扩增和新的测序技术。这将使人们对生物多样性公约的能力以及对环境和进化的适应有全面的了解。关于这些难以捉摸的细菌和它们的宿主的史无前例的数据可能对应用和农业方面也非常有趣。我们预计BLO基因组序列信息可能揭示必要或有利的代谢途径、抗生素合成或耐药性、AM进化的假定意义(例如，通过水平基因转移)以及几个不可预见的方面，如效应器分泌的提示。

Arbuscular mycorrhizal fungi (AMF), symbionts of land plants for >400 million years (My), are known to host in their cytoplasm Gram-positive endobacteria traditionally called bacterium-like organisms (BLOs). Recently, we could show that 16S rDNA sequences of AMF-BLOs (from highly diverse AMF lineages) all fall in a >400 My old monophyletic clade in the class Mollicutes. Despite the fact that the uncultivable BLOs must play an important, maybe organelle-like role in AMF, their function is thus far unknown. In this project, we aim to achieve a full sequencing of the genomes of BLOs to founder understanding their functioning in the important AM symbiosis. Within a single AMF spore BLOs are genetically polymorphic. To explore and annotate their metagenome and individual genome sequences, we will use two well defined AMF isolates and combine metagenomics, single cell sorting, whole genome amplification and new sequencing technologies. This will provide comprehensive insights into the capacities and environmental and evolutionary adaptations of BLOs. The unprecedented data regarding these elusive bacteria and their hosts potentially are highly interesting also for applied, agricultural aspects. We anticipate that BLO genome sequence information may reveal essential or advantageous metabolic pathways, antibiotics-synthesis or -resistance, putative significance for AM evolution (e.g., by horizontal gene transfer), and several unforeseeable aspects, like hints for effector secretion.