盐胁迫对花生种子际细菌菌群结构的调控

盐胁迫影响种子萌发和植株形态建成，提高盐胁迫下花生种子萌发速率和成苗健苗率是盐碱地花生高产高效栽培的重要环节之一，花生种子际土壤细菌菌群结构与种子萌发关系密切。为揭示盐胁迫对花生种子际微生物菌群结构的影响，以耐盐花生品种（花育25号，HY25）和盐敏感花生品种（花育20号，HY20）为试验材料，采用盆栽实验和高通量测序技术，研究不同耐盐性品种种子萌发吸胀吸水阶段种子际细菌菌群结构的变化。结果表明，种子际土壤细菌群落以变形菌门（Proteobacteria）、厚壁菌门（Firmicutes）、放线菌门（Actinobacteria）、拟杆菌门（Bacteroidetes）及芽单胞菌门（Gemmatimonadetes）等为优势菌门，盐胁迫处理可以不同程度的提高厚壁菌门和放线菌门的相对丰度。在属水平上，盐胁迫可以增加有益菌芽胞杆菌属（Bacillus）的相对丰度，增强盐胁迫下种子存活能力，提高萌发率。细菌功能预测结果显示，信号转导机制、免疫系统和防御机制等相关功能在盐胁迫处理后明显增强，可能是促进花生萌发并增强花生胁迫应答的重要原因之一。种子际优势菌群的鉴定及机理分析可为通过改良种子际土壤微生物环境，提高花生耐盐性和出苗健苗率提供重要的借鉴意义，同时为开发利用盐碱地提供参考。

Regulation of Salt Coercion on Peanut Spermosphere Bacterial Community Structure

Seed germination and plant morphogenesis of peanut (Arachis hypogaea L.) were affected by salt coercion. The seed germination rate and healthy seedling rate of peanut is one of important links in high yielding and high efficiency cultivation of peanut in saline-alkali soil. Peanut spermosphere soil bacterial community structure is closely related to seed germination. The aim of this study was to reveal the effect of salt coercion to peanut spermosphere community structure. The salt-resistant peanut cultivar (Huayu 25, HY25) and salt-susceptible peanut cultivar (Huayu 20, HY20) were planted adopted pot experiment, and the high-throughput sequencing was performed to study the changes of bacterial community structure in imbibition and water uptaking stage during seed germination of different salt-tolerant cultivars. The results showed that Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, and Gemmatimonadetes were the dominant phyla in the peanut spermosphere. Comparisons of the bacterial community structure of peanuts revealed that the relative abundance of Firmicutes and Actinobacteria dramatically increased in salt-treated spermosphere soil. At the genus level, salt coercion increased the relative abundance of Bacillus, which can enhance the viability of seeds and improve the germination rate under salt coercion. Bacterial function prediction results showed that signals transduction mechanism, immune system, and defense mechanism and others correlated functions were significantly improved after salt coercion treatment, which may be one of the important reasons to promoting peanut germination and enhancing peanut coercion responses. The identification and mechanism analyses of the dominant bacteria in spermosphere could provide important foundation for future improvement of salt tolerance and healthy seedling rate of peanuts via modification of the soil microbial environment. And the study also provides theoretical and technical basis for the development and utilization of saline-alkali soil.