Söllinger Andrea, Séneca Joana, Borg Dahl Mathilde, Motleleng Liabo L, Prommer Judith, Verbruggen Erik, Sigurdsson Bjarni D, Janssens Ivan, Peñuelas Josep, Urich Tim, Richter Andreas, Tveit Alexander T
Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway.
Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.
Sci Adv. 2022 Mar 25;8(12):eabm3230. doi: 10.1126/sciadv.abm3230.
How soil microorganisms respond to global warming is key to infer future soil-climate feedbacks, yet poorly understood. Here, we applied metatranscriptomics to investigate microbial physiological responses to medium-term (8 years) and long-term (>50 years) subarctic grassland soil warming of +6°C. Besides indications for a community-wide up-regulation of centralmetabolic pathways and cell replication, we observed a down-regulation of the bacterial protein biosynthesis machinery in the warmed soils, coinciding with a lower microbial biomass, RNA, and soil substrate content. We conclude that permanently accelerated reaction rates at higher temperatures and reduced substrate concentrations result in cellular reduction of ribosomes, the macromolecular complexes carrying out protein biosynthesis. Later efforts to test this, including a short-term warming experiment (6 weeks, +6°C), further supported our conclusion. Down-regulating the protein biosynthesis machinery liberates energy and matter, allowing soil bacteria to maintain high metabolic activities and cell division rates even after decades of warming.
土壤微生物如何应对全球变暖是推断未来土壤-气候反馈的关键，但目前对此了解甚少。在此，我们应用宏转录组学来研究微生物对亚北极草原土壤中期（8年）和长期（>50年）+6°C变暖的生理反应。除了表明中心代谢途径和细胞复制在群落范围内上调外，我们还观察到变暖土壤中细菌蛋白质生物合成机制的下调，这与较低的微生物生物量、RNA和土壤底物含量相一致。我们得出结论，较高温度下永久加速的反应速率和底物浓度的降低导致细胞中核糖体数量减少，核糖体是进行蛋白质生物合成的大分子复合物。后来为验证此结论所做的努力，包括一项短期变暖实验（6周，+6°C），进一步支持了我们的结论。下调蛋白质生物合成机制可释放能量和物质，使土壤细菌即使在经历数十年变暖后仍能维持较高的代谢活性和细胞分裂速率。
