Journal of Hazardous Materials, 2023, https:// doi: 10.1016/j.j

Abstract

Mesosulfuron-methyl is a widely used herbicide in wheat fields. We previously reported that mesosulfuron-methyl alters the bacterial/fungal community structure in experimental indoor microcosms, ultimately affecting NO₃^--N and NH₄⁺-N contents in soil nitrogen (N) cycling. However, how mesosulfuron-methyl application alter soil N cycling by changing microbial community assembly is unknown. Here, we designed an outdoor experiment comprising 2-month periods to investigate changes in soil N-cycle functional genes and structural shifts in the microbial community assembly in response to mesosulfuron-methyl applied at 11.25 and 112.5 g a.i. hm^-2. Results showed that high mesosulfuron-methyl input significantly decreased AOA  amoA  and  nirK  abundances within the initial 15 days, but increased AOB  amoA  on day 60. The nifH abundance displayed a stimulation-inhibition trend. Moreover, high mesosulfuron-methyl input decreased the network's complexity, and newly formed multiple network modules exhibited strong negative associations with  nifH, AOB amoA, nirK  and  nirS . Further structural equation model demonstrated that mesosulfuron-methyl did reveal strong direct inhibition of  nirK, and it indirectly affected  nirK  by changing  nifH  abundance and  Planomicrobium . Thus mesosulfuron-methyl perturbs N-cycling processes by reshaping bacterial community assembly. Taken together, our study provides theoretical support for determining the microbiological mechanism by which mesosulfuron-methyl affects soil N cycling.

Journal of Hazardous Materials,IF=13.6

https://pubmed.ncbi.nlm.nih.gov/36444049/