辐射污染区盐爪爪根际微生物群落演替及辐射胁迫响应规律研究

Rhizosphere microorganisms take part in important physiological activities and play important roles in the rhizosphere. There are significant value on theory and application. The composition and distribution of rhizosphere microorganisms mainly depends on the plant species, but was influenced by a variety of factors. Radionuclide contamination can result in stress both heavy metals and radiation, however, we know less about response of rhizosphere microorganisms to radionuclide contamination. Moreover, there are limited studies focused on microbial diversity in the rhizosphere of halophytes. .This project intends to reveal microbial diversity and metabolic characteristics in the rhizosphere of which is a kind of typical halophytes widely distributed in Chinese nuclear radiation pollution areas located in Xinjiang, state the microbial community succession and analyze the response to radiation stress in the rhizosphere. Investigations will be carried out by using the Biolog Eco method and high-throughput sequencing technology and isolates screening both in different growth stages and under different radiation intensities. Meanwhile, in order to discuss the role of rhizosphere microorganisms in radionuclide migration, isolates were screened with related resistance to radiation, and the ability of uptake and accumulation of radionuclide was test. .With the project processing, it will further reveal the distribution and evolution of microbial community under radiation stress, and provide microbial resources for radionuclides bioremediation.

根际微生物参与并承担了根际重要的生理活动，具有重要的理论研究和应用价值。根际微生物群落组成和分布主要取决于植物种类，但也受到多种因素影响。核辐射污染兼具重金属和放射性双重污染，其对根际微生物群落影响目前知之甚少。同时，盐生植物根际微生物多样性研究也较为有限。因此，本项目拟以中国核辐射污染区典型盐生植物盐爪爪根际微生物为研究对象，采用Biolog Eco方法和高通量测序技术，并结合传统的菌种分离筛选，开展不同辐射强度下各生长阶段盐爪爪根际微生物群落组成和分布研究，以期从多角度揭示其微生物和代谢功能特征，阐明其群落的演替过程，并解析辐射胁迫下其群落响应规律。同时，筛选获得一批耐辐射相关微生物资源，考查其对核素的吸收和富集能力，以探讨其在盐爪爪根际放射性核素迁移中的作用。上述研究的开展，将进一步揭示辐射胁迫下微生物分布演变规律，也为放射性核素的生物治理提供研究基础。

根际微生物作为土壤-植物间物质交换界面的重要的成员，参与担负着根际重要的生理活动，具有重要的理论研究和应用价值。目前有关盐生植物根际微生物多样性研究较为有限，且核辐射污染兼具重金属和放射性双重污染，国内外对其胁迫下根际群落响应更是知之甚少。本项目以中国核辐射污染区典型盐生植物盐爪爪根际微生物为研究对象，开展了辐射污染区盐爪爪根际微生物群落组成和菌株功能研究。. 通过研究，项目明确了盐爪爪根际微生物主要群落组成和多样性分布，解析了不同辐射污染程度下盐爪爪根际微生物组成分布的影响，发现了随着辐射程度的增加，其根际变形杆菌门丰度增加，而拟杆菌门丰度明显下降；同时，发现盐爪爪根际对变形杆菌门、Fibrobacteres、Hydrogenedentes等菌门微生物富集作用明显，并在碳源利用上存在着明显的演变规律。实验先后从辐射污染区盐爪爪根际分离微生物500余株，发现潜在新种10余个，发现其绝大多数菌株具有耐盐、耐高（低）温等抗逆特性，完成了2株新种的系统鉴定，其中已发表相关新种文章1篇。实验分离获得一批具有耐盐促生作用的微生物，并利用盆栽实验验证了其对棉花的耐盐促生效果。实验获得一批具有酚类降解微生物，并进行了其降解苯酚和玉米赤霉烯酮的条件优化。上述研究结果，为盐爪爪根际微生物在农业生产、环境治理以及生物脱毒的领域的应用奠定了良好基础。