根际细菌群落结构与装配对烟草根系生长性状的影响

Effects of Rhizosphere Bacterial Community Structure and Developmental Assembly on Tobacco Root Growth Traits

植物根际微生物与植物生长密切相关,但根际微生物群落如何影响根系的发育情况仍研究甚少。本研究利用16S rRNA基因高通量测序技术检测了烟草的根际细菌群落,并探究了烟草根系不同发育情况与根际微生物群落差异的关联机制。结果表明:相比不发达根系(UDR),发达根系(WDR)的根际细菌物种的丰度和多样性均较高,Gallionella和Luteimona等属的丰度显著增加,而Edaphobaculum、PLTA13和Rhodobacter等属的丰度则显著降低(P<0.05);UDR的分子生态网络更加复杂,且物种间相互作用强,特别是合作行为,而WDR的网络关键节点数较多,其碳循环相关网络模块数与UDR相比增加;此外,WDR的根际细菌群落装配更趋向于发育聚集,且环境过滤在其中发挥了更重要的作用。总体上,本研究结果强调了根际微生物群落的结构组成、网络变化和群落装配在植物根系的生长过程中的重要作用,为植物根际微生物生态学研究提供了理论依据。

Plant rhizosphere microbes are closely related to plant growth, whereas how the rhizosphere microbial community affects root development remains poorly understood. In this study, 16S rRNA gene high-throughput sequencing technology was used to detect the bacterial community of tobacco rhizosphere, and to explore the association mechanism between different developmental conditions of tobacco roots and differences in rhizosphere microbial community. The results showed that the species richness and diversity of rhizosphere bacteria in the well-developed root system(WDR) were higher than those in the undeveloped root system(UDR), with the genera Gallionella and Luteimona significantly increased, while the genera Edaphobaculum, PLTA13 and Rhodobacter significantly increased. Abundance significantly reduced(P<0.05). The molecular ecological network of UDR is more complex, and the interaction between species is strong, especially the cooperative behavior. The number of key nodes in the WDR network is more, and its carbon cycle related network modules increase. In addition, the WDR rhizosphere bacterial community assembly tends to be more developmentally aggregated, and environmental filtering plays a more important role in it. Overall, the results of this study emphasize that the structural composition, network changes and community assembly of the rhizosphere microbial community play an important role in the development of plant roots, and provide a theoretical basis for regulating the rhizosphere microbial community to promote plant root growth.