题目：The root microbiome: Community assembly and its contributions to plant fitness 根系微生物组：群落构建及其对植物适应性的贡献
The root microbiome refers to the community of microbes living in association with a plant’s roots, and includes mutualists, pathogens, and commensals. 根系微生物组是指与植物的根（气生根）一起生活的微生物群落，它们有的与植物互惠（有利），有的是病原（有害），有的只是一起生活（共栖），并无太大作用（中性）。 Q: 如何定义和分类？ Mutualists are microbes that establish specific mutualistic structures with plants, such as arbuscular mycorrhizae, which assist in phosphate absorption (Toro et al., 1997; Ezawa and Saito, 2018), and rhizobia, which widely colonize legumes to form nitrogen‐fixing root nodules (Masson‐Boivin and Sachs, 2018; Lindstrom and Mousavi, 2020). Mutualists obtain essential carbon sources from the plants, which in turn can absorb mineral nutrients such as nitrogen and phosphorus via the mutualists.
Pathogens are microbes that lead to specific diseases after colonization such as Pseudomonas syringae (Nomura et al., 2005; Xin et al., 2018).
Commensals constitute the majority of plant‐associated microbes and include bacteria, fungi, archaea, viruses, and protozoa; they are loosely dependent on hosts but can be recruited in certain situations to influence hosts growth and development through neutral, beneficial or harmful interactions (Hooper and Gordon, 2001). However, with in‐depth study, specific commensals may prove to be mutualists or pathogens.
Here we focus on recent advances in the study of root commensal community which is the major research object of microbiome‐ related researches. 这里我们关注最近根共栖微生物群落这一微生物组研究中很主流的一类研究。 With the rapid development of new technologies, plant–commensal interactions can be explored with unprecedented breadth and depth. 新技术，深度广度。 Both the soil environment and the host plant drive commensal community assembly. 土壤和宿主是决定共栖微生物群落构建的两大因素。 The bulk soil is the seed bank of potential commensals, and plants use root exudates and immune responses to build healthy microbial communities from the available microbes. 以土壤微生物为来源，植物利用根系分泌物来吸引，同时通过自身免疫反应来阻挡，从而构建出一个健康的根系微生物群落。 The plant microbiome extends the functional system of plants by participating in a variety of processes, including nutrient absorption, growth promotion, and resistance to biotic and abiotic stresses. 植物微生物组扩大了植物的功能系统，参与了宿主在营养吸收、生长促进以及应对生物与非生物压力上的多种过程。 Plants and their microbiomes have evolved adaptation strategies over time. 植物和它们的微生物组都随时间进化出了适应的策略。 However, there is still a huge gap in our understanding of the regulatory mechanisms of plant– commensal interactions. 但是，我们对植物和它们的共栖微生物之间的互作的调节机制的理解还很有限。 In this review, we summarize recent research on the assembly of root microbial communities and the effects of these communities on plant growth and development, and look at the prospects for promoting sustainable agricultural development through the study of the root microbiome. 在这篇综述里面，我们会总结最近在根系微生物群落的构建，它们对植物的生长发育的影响，以及这些研究对可持续发展农业可能的促进。
Content
## Root microbiota community structure and assembly patterns ## Main factors affecting the root microbiota ### Soil is a critical factor affecting the root microbiota The bulk soil microbiota - A “seed bank” of plant root microbes. Soil Physicochemical properties also affect root microbiota structure indirectly by affecting plants ### The host regulates the root microbiota Rhizosphere effects: root exudates drive microbiome assembly The plant immune system idstinguishes “enemies” and “friends”. Other host genes regulating the assembly of root microbiome ### Microbe-microbe interactions during microbial community assembly