Séneca Joana, Söllinger Andrea, Herbold Craig W, Pjevac Petra, Prommer Judith, Verbruggen Erik, Sigurdsson Bjarni D, Peñuelas Josep, Janssens Ivan A, Urich Tim, Tveit Alexander T, Richter Andreas
Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.
Department of Arctic and Marine Biology, UiT, The Arctic University of Norway, Tromsø, Norway.
ISME Commun. 2021 Nov 25;1(1):69. doi: 10.1038/s43705-021-00073-5.
Global warming increases soil temperatures and promotes faster growth and turnover of soil microbial communities. As microbial cell walls contain a high proportion of organic nitrogen, a higher turnover rate of microbes should also be reflected in an accelerated organic nitrogen cycling in soil. We used a metatranscriptomics and metagenomics approach to demonstrate that the relative transcription level of genes encoding enzymes involved in the extracellular depolymerization of high-molecular-weight organic nitrogen was higher in medium-term (8 years) and long-term (>50 years) warmed soils than in ambient soils. This was mainly driven by increased levels of transcripts coding for enzymes involved in the degradation of microbial cell walls and proteins. Additionally, higher transcription levels for chitin, nucleic acid, and peptidoglycan degrading enzymes were found in long-term warmed soils. We conclude that an acceleration in microbial turnover under warming is coupled to higher investments in N acquisition enzymes, particularly those involved in the breakdown and recycling of microbial residues, in comparison with ambient conditions.
全球变暖会提高土壤温度，促进土壤微生物群落更快地生长和更替。由于微生物细胞壁含有高比例的有机氮，微生物更高的更替率也应反映在土壤中有机氮循环的加速上。我们采用宏转录组学和宏基因组学方法来证明，在中期（8年）和长期（>50年）变暖的土壤中，编码参与高分子量有机氮胞外解聚的酶的基因的相对转录水平高于环境土壤。这主要是由编码参与微生物细胞壁和蛋白质降解的酶的转录本水平增加所驱动的。此外，在长期变暖的土壤中发现了几丁质、核酸和肽聚糖降解酶的更高转录水平。我们得出结论，与环境条件相比，变暖条件下微生物更替的加速与对氮获取酶的更高投入有关，特别是那些参与微生物残体分解和循环利用的酶。
