Stimulatory effects of growing plants on nitrous oxide (N₂O) emissions have been widely reported in terrestrial ecosystems, but the potential mechanisms responsible for these effects remain unclear. This study revealed that wheat can induce a 3.5–9.2-fold increase in N₂O emissions under different soil fertility levels, and that this “plant” source of N₂O occurs in the rhizosphere. Moreover, plants induced soil niche differentiation between denitrifiers harboring the nitrous oxide reductase genes nosZI and nosZII. Pulse labeling of wheat demonstrated that 67% of ¹³C-labeled nosZI-type denitrifiers, but no nosZII-type denitrifiers, were more abundant in the rhizosphere than in bulk soil. Furthermore, a higher percentage of bacterial genomes containing nitrite reductase genes was found within plant-associated nosZI-type denitrifiers than nosZII-type denitrifiers, favoring NO₂⁻ to N₂O conversion. Overall, this study revealed a strong selective stimulating effect of wheat on soil denitrifiers through root-derived carbon and a key role of the nosZI-type community in rhizosphere denitrification.

在陆地生态系统中，已经广泛报道了生长中的植物对一氧化二氮（N ₂ O）排放的刺激作用，但是导致这些作用的潜在机制仍不清楚。这项研究表明，在不同的土壤肥力水平下，小麦可导致N ₂ O排放增加3.5-9.2倍，而这种N ₂ O的“植物”来源发生在根际。此外，植物在具有一氧化二氮还原酶基因nosZ I和nosZ II的反硝化剂之间诱导了土壤生态位的分化。小麦的脉冲标记表明^13种C标记的nosZ I型反硝化剂中有67％，但没有nosZII型反硝化剂在根际中比在大量土壤中含量更高。此外，含亚硝酸盐还原酶基因的细菌基因组的更高百分比的植物相关内发现nosZ I型反硝化菌比nosZ II型反硝化菌，有利于NO ₂ ^-到N ₂ O转换。总体而言，这项研究揭示了小麦通过根源碳对土壤反硝化剂的强烈选择性刺激作用，以及nosZ I型群落在根际反硝化中的关键作用。