Institute for Plant Molecular Biology, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China.
Microb Biotechnol. 2022 Dec;15(12):2942-2957. doi: 10.1111/1751-7915.14164. Epub 2022 Nov 6.
Plant roots significantly influence soil microbial diversity, and soil microorganisms play significant roles in both natural and agricultural ecosystems. Although the genetically modified (GM) crops with enhanced insect and herbicide resistance are thought to have unmatched yield and stress resistance advantages, thorough and in-depth case studies still need to be carried out in a real-world setting due to the potential effects of GM plants on soil microbial communities. In this study, three treatments were used: a recipient soybean variety Jack, a triple transgenic soybean line JD321, and the glyphosate-treated JD321 (JD321G). Three sampling stages (flowering, seed filling and maturing), as well as three host niches of soybean rhizosphere [intact roots (RT), rhizospheric soil (RS) and surrounding soil (SS)] were established. In comparison to Jack, the rhizospheric soil of JD321G had higher urease activity and lower nitrite reductase at the flowering stage. Different treatments and different sampling stages existed no significant effects on the compositions of microbial communities at different taxonomic levels. However, at the genus level, the relative abundance of three plant growth-promoting fungal genera (i.e. Mortierella, Chaetomium and Pseudombrophila) increased while endophytic bacteria Chryseobacterium and pathogenic bacteria Streptomyces decreased from the inside to the outside of the roots (i.e. RT → RS → SS). Moreover, two bacterial genera, Bradyrhizobium and Ensifer were more abundant in RT than in RS and SS, as well as three species, Agrobacterium radiobacter, Ensifer fredii and Ensifer meliloti, which are closely related to nitrogen-fixation. Furthermore, five clusters of orthologous groups (COGs) associated to nitrogen-fixation genes were higher in RT than in RS, whereas only one COG annotated as dinitrogenase iron-molybdenum cofactor biosynthesis protein was lower. Overall, the results imply that the rhizosphere host niches throughout the soil-plant continuum largely control the composition and function of the root-associated microbiome of triple transgenic soybean.
植物根系对土壤微生物多样性有显著影响，而土壤微生物在自然和农业生态系统中都起着重要作用。虽然具有增强抗虫和除草剂特性的转基因（GM）作物被认为具有无与伦比的产量和抗逆优势，但由于 GM 植物对土壤微生物群落可能产生的影响，仍需要在真实环境中进行彻底和深入的案例研究。在这项研究中，使用了三种处理方法：受体大豆品种 Jack、三重转基因大豆品系 JD321 和草甘膦处理的 JD321（JD321G）。建立了三个采样阶段（开花、种子填充和成熟）以及大豆根际的三个宿主小生境[完整根系（RT）、根际土壤（RS）和周围土壤（SS）]。与 Jack 相比，JD321G 的根际土壤在开花期具有更高的脲酶活性和更低的亚硝酸盐还原酶活性。不同的处理和不同的采样阶段对不同分类水平的微生物群落组成没有显著影响。然而，在属水平上，三种植物促生真菌属（即 Mortierella、Chaetomium 和 Pseudombrophila）的相对丰度增加，而内生细菌 Chryseobacterium 和病原细菌 Streptomyces 则从根系内部到外部减少（即 RT→RS→SS）。此外，两个细菌属 Bradyrhizobium 和 Ensifer 在 RT 中的丰度高于 RS 和 SS，以及三个与固氮相关的种，Agrobacterium radiobacter、Ensifer fredii 和 Ensifer meliloti。此外，五个与固氮基因相关的直系同源基因簇（COGs）在 RT 中的丰度高于 RS，而只有一个注释为固氮酶铁钼辅因子生物合成蛋白的 COG 较低。总的来说，这些结果表明，整个土壤-植物连续体的根际宿主小生境在很大程度上控制了三重转基因大豆根相关微生物组的组成和功能。
