The translation of plant residue carbon in plant–soil–microbe systems under atmospheric CO (aCO) and elevated CO (eCO) is key to understanding the response of ecosystems to climatic change. Using stable isotope probing technology, we conducted an experiment on 3.5 g·kg tomato C-residue (1050 ‰) added to tomato soils to investigate the decomposition and incorporation of C-residue under varied CO concentrations (aCO and eCO: 400 and 800 μmol·mol, respectively). The results showed that the C-residue decomposition rate was stimulated by approximately 7.2 % and the C amount in plant stems was stimulated by 15.6 % (22.2 vs. 19.2 μg/pot), while the total C amount in soil microbial phospholipid fatty acids (PLFAs) was significantly decreased by 16.3 % (541 vs. 646 nmol·g), the DNA δC in soil microbes decreased by 5.1 % (−27.629 ‰ vs. −26.289 ‰), and soil δC decreased by 7.1 % (49.9 ‰ vs. 53.7 ‰) under eCO. The microbial community structure involved in C-residue incorporation was significantly affected by the CO concentration. ( 20.4 % and 20.4 %) and ( 6.6 %) were the dominant phyla under aCO and eCO, respectively. () were the most depleted microbes under eCO, whereas almost no genera were found under aCO. The C-residue decomposition rate was positively correlated with soil NO-N ( = 0.998, < 0.05) at t1 (17 days of cultivation under varied CO concentrations), and DNA δC was positively related with soil pH ( = 0.978, < 0.05) at t2 (35 days of cultivation under varied CO concentrations). Mantel tests showed that the microbial community composition involved in C incorporation was significantly correlated with the soil pH under various CO conditions ( = 0.879, < 0.05). These results indicate that eCO stimulated the decomposition of C-residue and the transportation of C to the plant stem, but suppressed the incorporation of C into microbes (PLFA and DNA), which were adjusted by the rhizosphere N status and soil pH.

中文翻译：

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升高的 CO2 增强了植物中 13C 残留物的吸收，但抑制了番茄 (Solanum lycopersicum L.) 根际土壤微生物中的 13C 残留物吸收

在大气 CO (aCO) 和升高的 CO (eCO) 条件下植物-土壤-微生物系统中植物残留碳的转化是了解生态系统对气候变化响应的关键。采用稳定同位素探测技术，将3.5 g·kg番茄碳渣（1050‰）添加到番茄土壤中，研究不同CO浓度（aCO和eCO：400和800 μmol）下碳渣的分解和掺入情况。分别为·mol）。结果表明，碳残留分解率提高了约7.2%，植物茎中的碳量提高了15.6%（22.2 vs. 19.2 μg/盆），而土壤微生物磷脂脂肪酸中的总碳量（ PLFAs）显着下降16.3%（541 vs. 646 nmol·g），土壤微生物DNA δ13C下降5.1%（-27.629 ‰ vs. -26.289 ‰），土壤δ13C下降7.1 %（49.9 ‰ vs. . 53.7 ‰) 在 eCO 下。参与 C 残基掺入的微生物群落结构受 CO 浓度的显着影响。 (20.4%和20.4%)和(6.6%)分别是aCO和eCO下的优势门。 () 是 eCO 下最贫乏的微生物，而 aCO 下几乎没有发现任何属。 t1（不同CO浓度下培养17天）时，碳残基分解率与土壤NO-N（= 0.998，< 0.05）呈正相关，DNA δ13C与土壤pH值呈正相关（= 0.978，< 0.05） t2（在不同 CO 浓度下培养 35 天）。 Mantel测试表明，在不同CO条件下，参与C掺入的微生物群落组成与土壤pH值显着相关（=0.879，<0.05）。这些结果表明，eCO 刺激了碳残基的分解以及碳向植物茎的运输，但抑制了碳向微生物（PLFA 和 DNA）的吸收，而微生物（PLFA 和 DNA）的吸收是通过根际氮状态和土壤 pH 值进行调节的。