School of Applied Meteorology, Nanjing University of Information Science & Technology, No. 219 Ningliu Road, Nanjing 210044, China.
Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China; Department of Animal, Plant & Soil Sciences, Centre for AgriBioscience, La Trobe University (Melbourne Campus), Bundoora, Vic 3086, Australia.
Sci Total Environ. 2021 Apr 10;764:142836. doi: 10.1016/j.scitotenv.2020.142836. Epub 2020 Oct 8.
Changes in rhizodeposits of crops under elevated CO (eCO) and elevated temperature (eT) may substantially impact on soil microbial community, which in turn affects soil carbon and nutrient cycling. However, the responses of soil bacterial community to long-term eCO and eT are not fully understood. A seven-year field experiment using open-top chambers was carried out with soybean (Glycine max L. Merr.) and maize (Zea mays L.) grown in a Mollisol soil under ambient CO (380 ppm), eT (2.1 °C increase in air temperature) and eTeCO (elevated temperature plus elevated CO, 2.1 °C increase in air temperature and 700 ppm CO). Soil DNA was extracted for Illumina MiSeq sequencing. The principal coordinate analysis showed that changes of bacterial community structure due to eT and eTeCO were greater in soybean- than maize-grown soils. The eT increased the relative abundances of Gaiella and Bacillus in Actinobacteria and Firmicutes, but decreased those of Nocardioides and H16 in Actinobacteria and Proteobacteria, respectively. The magnitudes of responses of seven genera sensitive to eT varied between soybean- and maize-grown soils. The eTeCO decreased the relative abundance of Bacillus and increased those of Gaiella, Streptomyces and Mizugakiibacter. The abundances of Gaiella, Gemmatimonas, and Mizugakiibacter under eTeCO were higher in soybean- than maize-grown soils. The redundancy analysis showed that soil organic C, moisture, nitrate, microbial biomass N and Olsen-P significantly affected soil bacterial community composition. All these results indicate that long-term eT increased the abundance of bacterial community and shifted their composition compared to the ambient control. In addition, the bacterial community composition under eTeCO was more stable in maize- than soybean-grown soils. The study suggests that warming and crop species may interactively affect the stability of bacterial community linking to the sustainability of soil eco-function in future cropping systems.
在高浓度二氧化碳 (eCO) 和高温 (eT) 条件下，作物根分泌物的变化可能会对土壤微生物群落产生重大影响，进而影响土壤碳和养分循环。然而，长期 eCO 和 eT 对土壤细菌群落的响应还不完全清楚。本研究采用开顶式气室进行了为期 7 年的田间试验，在潮土中种植大豆 (Glycine max L. Merr.) 和玉米 (Zea mays L.)，对照 (CO 浓度为 380 ppm)、增温 (空气温度升高 2.1°C) 和增温增 CO (空气温度升高 2.1°C，CO 浓度升高 700 ppm)。提取土壤 DNA 进行 Illumina MiSeq 测序。主坐标分析表明，eT 和 eTeCO 引起的细菌群落结构变化在大豆土中大于玉米土。eT 增加了放线菌和厚壁菌门中 Gaiella 和 Bacillus 的相对丰度，但分别降低了放线菌和变形菌门中 Nocardioides 和 H16 的相对丰度。对 eT 敏感的 7 个属的响应幅度在大豆土和玉米土之间存在差异。eTeCO 降低了 Bacillus 的相对丰度，增加了 Gaiella、Streptomyces 和 Mizugakiibacter 的相对丰度。eTeCO 下 Gaiella、Gemmatimonas 和 Mizugakiibacter 的丰度在大豆土中高于玉米土。冗余分析表明，土壤有机碳、水分、硝酸盐、微生物生物量氮和 Olsen-P 显著影响土壤细菌群落组成。这些结果表明，与对照相比，长期 eT 增加了细菌群落的丰度并改变了其组成。此外，在玉米土中，eTeCO 下的细菌群落组成比大豆土更稳定。研究表明，增温和作物种类可能会相互作用，影响与未来种植系统土壤生态功能可持续性相关的细菌群落稳定性。
