磷素是植物生长所必需的营养元素，其在大豆等豆科植物的共生结瘤过程中也有重要作用。尽管研究者认为根际微生物能通过溶磷作用促进植物对磷素的吸收，但目前人们对在根际区域参与了磷素转化过程的主要功能微生物类群的结构和演替规律知之甚少，也无法检测和验证该功能微生物类群对不同形态磷素的矿化分解能力，因此也就不能准确地描述根际微生物通过对磷素的分解，来提高磷素供给量，进而促进豆科植物生长和结瘤固氮的详细过程。本项目拟通过温室植物栽培试验，应用高通量测序和同位素示踪等技术手段，揭示在大豆根际区域分布的与磷素形态转化相关的功能微生物类群的组成和结构，分析土壤和植物等因素对该功能微生物类群组成、结构和演替过程的影响，验证该功能微生物类群对不同形态磷素的矿化分解能力，明确这些磷素被分解后的吸收和利用过程，全面系统地阐明由根际功能微生物参与的磷素转化过程及其对大豆生长和结瘤的影响。

Phosphorus is a necessary nutritional element for plant growth. It also plays an important role in the rhizobia and leguminous plants (such as soybean) symbiotic nodulation. Researchers suggested that some microorganisms could accelerate the decomposition of phosphorus in rhizosphere region and improve the plant phosphorus acquisition. But, so far at least, our knowledges about the structure and succession rule of functional microbial group which can promote the transformation of phosphorus in rhizosphere are very pool. As a result, there are very few studies trying to test and verify the abilities of these functional microorganisms to decompose different forms of phosphorus in rhizosphere, and very few studies can describe the whole process of these functional microorganisms to promote the plant growth and nodulation by increasing the phosphorus decomposition and supplement for plant. In this study, we will carry out some greenhouse plant cultivation experiments, using high-throughput sequencing and isotopic tracer technique, to reveal the composition and structure of functional microbial group which are connected with the phosphorus transformation in the soybean rhizosphere region, to analyze the influences of soil and plant factors on the composition, structure and succession rule of the functional microbial group, to verify the abilities of the functional microbial group to decompose different forms of phosphorus, to explore the process of plant absorbing and using these phosphorus. In the end, we will clarify the phosphorus transformation process led by the functional microbial group in soybean rhizosphere and its influences on the soybean plant growth and nodulation comprehensively and systematically.