Agronomy-Basel
·
2023
·Vol. 13
·期 1
·216
·
IF 3.7
Guangtao Zhu,Hao Wang,Haitao Gao,Ying Liu,Jun Li,Zhike Feng,Liyao Dong
Italian ryegrass (Lolium multiflorumL.), a cross-pollinated grass, is gradually becoming a predominant weed in wheat fields in China and is evolving resistance to many groups of herbicides. The aim of this study is to determine the resistance levels of a singleL. multiflorumpopulation from a wheat field in Henan Province China, to three modes of action (MoAs) of herbicides and to further characterize the potential resistance mechanisms. ThisL. multiflorumpopulation evolved multiple herbicide resistances to pyroxsulam [acetolactate synthase (ALS)], pinoxaden [acetyl-CoA carboxylase (ACCase)] and isoproturon [photosystem II (PSII)]. Target-site resistance (TSR) mutations (Pro-197-Gln, Pro-197-Thr, and Trp-574-Leu) and non-target-site resistance (NTSR) mediated by cytochrome P450 monooxygenase (CYP450) genes were associated with pyroxsulam resistance. Pinoxaden resistance was conferred by two TSR mutations, which referred to a rare Ile-2041-Val mutation and a common Ile-1781-Leu mutation but with two different nucleotide substitutions (CTA/TTA). CYP450- and glutathione-S-transferase (GST)-mediated resistances were the main resistance mechanisms for this multiple herbicide-resistant (MHR) population to the PSII inhibitor isoproturon. This is the first case of a singleL. multiflorumpopulation evolving multiple resistance to three herbicide MoAs (ALS, ACCase and PSII) in China. Diverse resistance mechanisms including TSR and NTSR meanL. multiflorumexhibits a high degree of resistance plasticity.Keywords:Lolium multiflorumL.;pyroxsulam;pinoxaden;isoproturon;multiple herbicide resistance;TSR;CYP450;GST
研究领域:
植物学
·
农学
·
杂草科学
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ENVIRONMENTAL MICROBIOLOGY
·
2026
·Vol. 28
·期 8
·e70398
·
IF 4
Yanning Tian,Lin Lai,Wenpei Wang,Yinhao Ma,Xing Huang
Ester‐containing pesticides, such as diphenyl ether herbicides, aryloxyphenoxypropionate herbicides, and strobilurin fungicides, are widely applied in agriculture, but their residues pose significant risks to ecosystems. Functional microorganisms can degrade ester‐containing pesticides in the natural environment. However, the microbial mechanisms responsible for their degradation in soils remain unclear. A novel hydrolase gene triS from the strain S113 encoded a broadly active carboxylesterase that hydrolyzes a wide range of ester‐containing pesticides. TriS exhibited a maximum sequence similarity of 34.92% to proteins in the Swiss‐Prot (UniProt) database. Gene redundancy was observed in strain S113, with TriS showing higher catalytic activity than its homologues. The enzyme contains a conserved Ser226‐Glu346‐His456 catalytic triad, and its substrate‐binding pocket can accommodate complex substrates, which contributes to its broad substrate spectrum and enhanced catalytic efficiency. Genomic analyses revealed that triS resides in a conserved locus, whereas related paralogs occupy more variable regions, suggesting potential horizontal dissemination. Bioinformatics‐based taxonomic profiling showed widespread occurrence of TriS homologues, mainly in agricultural soils, and also in forests and wetlands, indicating spread beyond pesticide‐treated fields. This study elucidated the function and distribution pattern of triS , enhancing our understanding of microbial ester‐containing pesticide degradation in the environment. A novel carboxylesterase, TriS, from strain Hansschlegelia zhihuaiae S113 degrades a wide range of ester‐bonded pesticides. Its structural features and widespread presence in both farmlands and natural areas help explain how microbial communities adapt to chemical stress and maintain key detoxification functions in the environment.
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PubMed
高影响因子
Microbial Cell Factories
·
2017
·Vol. 16
·期 1
·1-10
·
IF 3.681
Zhang Hui,Li Mengya,Li Jie,Wang Guangli,Liu Yuan
Quizalofop- p -ethyl (QPE) is a post-emergence herbicide that effectively controls grass weeds and is often detected in the environment. However, the biochemical and molecular mechanisms of QPE degradation in the environment remains unclear. In this study, a highly effective QPE-degrading bacterial strain J-2 was isolated from acclimated activated sludge and identified as a Pseudomonas sp., containing the QPE breakdown metabolite quizalofop acid (QA) identified by Liquid Chromatography-Ion Trap-Mass Spectrometry (LC-IT-MS n ) analysis. A novel QPE hydrolase esterase-encoding gene qpeH was cloned from strain J-2 and functionally expressed in Escherichia coli BL21 (DE3). The specific activity of recombinant QpeH was 198.9 ± 2.7 U mg −1 for QPE with K
m
and K
cat
values of 41.3 ± 3.6 μM and 127.3 ± 4.5 s −1 . The optimal pH and temperature for the recombinant QpeH were 8.0 and 30 °C, respectively and the enzyme was activated by Ca 2+ , Cd 2+ , Li + , Fe 3+ and Co 2+ and inhibited by Ni 2+ , Fe 2+ , Ag + , DEPC, SDS, Tween 80, Triton X, β-mercaptoethanol, PMSF, and pCMB. In addition, the catalytic efficiency of QpeH toward different AOPP herbicides in descending order was as follows: fenoxaprop-P-ethyl > quizalofop-P-tefuryl > QPE > haloxyfop-P-methyl > cyhalofopbutyl > clodinafop-propargyl. On the basis of the phylogenetic analysis and multiple sequence alignment, the identified enzyme QpeH, was clustered with esterase family V, suggesting a new member of this family because of its low similarity of amino acid sequence with esterases reported previously.
研究领域:
环境科学
·
分子生物学
·
生物化学
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PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2016
·
IF 4.836
Hui Zhang,Mengya Li,Jie Li,Guangli Wang,Feng Li,Dayong Xu,Yuan Liu,Minghua Xiong
A natural consortium, named L1, of Rhodococcus sp. JT-3 and Brevundimonas sp. JT-9 was obtained from quizalofop- p -ethyl (QE) polluted soil. The consortium was able to use QE as a sole carbon source for growth and degraded 100 mg L −1 of QE in 60 h. Strain JT-3 initiated the catabolism of QE to quizalofop acid (QA), which was used by strain JT-9 as carbon source for growth and to simultaneously feed strain JT-3. A novel esterase EstS-JT, which was responsible for the transformation of QE to QA and essential for the mineralization of QE by the consortium, was cloned from strain JT-3. EstS-JT showed low amino acid identity to other reported esterases from esterase family VIII and represents a new member of this family. The deduced amino acid sequence contained the esterase family VIII conserved motifs S-X-X-K, YSV and WAG. The purified recombinant EstS-JT displayed maximal esterase activity at 35 °C and pH 7.5. An inhibitor assay, site-directed mutagenesis and 3D modeling analysis revealed that S 64 , K 67 and Y 175 were essential for catalysis and probably comprised the catalytic center of EstS-JT. Additionally, EstS-JT had broad substrate specificity and was capable of hydrolyzing p -nitrophenyl esters (C 2 -C 8 ) and various AOPP herbicides.
研究领域:
环境科学
·
微生物学
·
生物化学
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PubMed
高影响因子