College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China.
College of Life and Environmental Science, Wenzhou University, Wenzhou, 325035, Zhejiang, China.
Environ Pollut. 2024 Sep 1;356:124254. doi: 10.1016/j.envpol.2024.124254. Epub 2024 May 28.
There is currently increasing pressure on agriculture to simultaneously remediate soil and ensure safe agricultural production. In this study, we investigate the potential of a novel combination of biochar and plant growth-promoting bacteria (PGPB) as a promising approach. Two types of biochar, corn stover and rice husk-derived, were used in combination with a PGPB strain, Bacillus sp. PGP5, to remediate Cd and Pb co-contaminated soil and enhance lettuce performance. The contaminated soil was pre-incubated with biochar prior to PGP5 inoculation. The combined application of biochar and PGPB reduced the diethylenetriaminepentaacetic acid (DTPA) -extractable Cd and Pb concentrations in the soil by 46.45%-55.96% and 42.08%-44.83%, respectively. Additionally, this combined application increased lettuce yield by 23.37%-65.39% and decreased Cd and Pb concentrations in the edible parts of the lettuce by 57.39%-68.04% and 13.57%-32.50%. The combined application showed a better promotion on lettuce growth by facilitating chlorophyll synthesis and reducing oxidative stress. These demonstrated a synergistic effect between biochar and PGPB. Furthermore, our study elucidated the specific role of the biochar-PGPB combination in soil microbial communities. Biochar application promoted the survival of PGP5 in the soil. The impact of biochar or PGPB on microbial communities was found to be most significant in the early stage, while the development of plants had a greater influence on rhizosphere microbial communities in later stage. Plants showed a tendency to recruit plant-associated microbes, such as Cyanobacteria, to facilitate growth processes. Notably, the combined application of biochar and PGPB expedited the assembly of microbial communities, enabling them more closely with the rhizosphere microbial communities in late stage of plant development and thus enhancing their effects on promoting plant growth. This study highlights the "accelerating" advantage of the biochar-PGPB combination in the assembly of rhizosphere microbiomes and offers a new strategy for simultaneous soil remediation and safe agricultural production.
目前，农业面临着同时修复土壤和确保农业安全生产的巨大压力。在这项研究中，我们研究了生物炭和植物促生菌（PGPB）的新型组合作为一种有前途的方法的潜力。我们使用了两种类型的生物炭，玉米秸秆和稻壳衍生的生物炭，与一种 PGPB 菌株芽孢杆菌 sp. PGP5 结合，以修复 Cd 和 Pb 复合污染土壤并提高生菜的性能。在接种 PGP5 之前，将污染土壤与生物炭预孵育。生物炭和 PGPB 的联合应用将土壤中 DTPA 可提取的 Cd 和 Pb 浓度分别降低了 46.45%-55.96%和 42.08%-44.83%。此外，这种联合应用使生菜产量增加了 23.37%-65.39%，并使生菜可食用部分的 Cd 和 Pb 浓度降低了 57.39%-68.04%和 13.57%-32.50%。联合应用通过促进叶绿素合成和减少氧化应激，对生菜生长表现出更好的促进作用。这表明了生物炭和 PGPB 之间的协同效应。此外，我们的研究阐明了生物炭-PGPB 组合在土壤微生物群落中的具体作用。生物炭的应用促进了 PGP5 在土壤中的存活。发现生物炭或 PGPB 对微生物群落的影响在早期最为显著，而植物的发展对后期根际微生物群落的影响更大。植物表现出招募与植物相关的微生物的趋势，如蓝细菌，以促进生长过程。值得注意的是，生物炭和 PGPB 的联合应用加速了微生物群落的组装，使它们在植物发育后期更接近根际微生物群落，从而增强了它们促进植物生长的效果。这项研究强调了生物炭-PGPB 组合在根际微生物组组装中的“加速”优势，并为同时进行土壤修复和安全农业生产提供了一种新策略。
