| Title: |
Biochar-derived persistent free radicals and reactive oxygen species reduce the potential of biochar to mitigate soil N2O emissions by inhibiting nosZ |
| Author: |
Wu, Ping; Xie, Minghui; Clough, Tim J.; Yuan, Dan; Wu, Sihuan; He, Xiaodong; Hu, Chunsheng; Zhou, Shungui; Qin, Shuping |
| PubYear: |
2023 |
| Publication Name: |
SOIL BIOLOGY & BIOCHEMISTRY |
| Volume、Issue、Page Number: |
178;
;
|
| Impact Factor: |
|
| Abstract: |
Biochar amendment has been proven to generally reduce soil nitrous oxide (N2O) emissions. However, the effects and underlying mechanisms of biochar-derived reactive oxygen species (ROS) on soil N2O emissions are still unclear. Thus, we firstly weakened the intensities of persistent free radicals (PFRs) within biochar using trie-thanolamine (TEA) as a quencher, and then used soil incubation methods to compare the potentials of TEA -quenched and un-quenched biochar in mitigating soil N2O emissions. The TEA-quenched biochar generated less hydrogen peroxide (H2O2) and hydroxyl radical (center dot OH), while having a higher soil N2O emission mitigation potential, than the un-quenched biochar. The N2O emissions and the N2O/(N2O + N2) ratio were significantly, positively, correlated with the generated H2O2 and center dot OH contents. These results demonstrated that biochar-derived ROS weakened biochar's mitigation of soil N2O emissions. The specific mechanisms of biochar-derived ROS on soil N2O emissions were further explored by a ROS scavenging experiment. It was found that scavenging H2O2 by catalase efficiently hindered the generation of center dot OH, resulting in decreases in N2O emissions and the N2O/(N2O + N2) ratio. Meanwhile, biochar-derived ROS exhibited a more severe inhibition on N2O reductase gene (nosZ) expression than that on the expression of genes responsible for N2O production (nirK and nirS), indicating that biochar-derived ROS weakened biochar's mitigation of soil N2O emissions by inhibiting microbial N2O reduction. Our results imply that controlling the content of biochar-derived ROS is a promising strategy to maximize biochar's potential for mitigating soil N2O emission. |
| DOI: |
http://dx.doi.org/10.1016/j.soilbio.2023.108970 |
| Download: |
|
