کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10235641 | 45050 | 2011 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Effects of the herbicides acetochlor and metolachlor on antioxidant enzymes in soil bacteria
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The aim of this study was to investigate the antioxidant responses of three bacteria (SD1, KD and K9) isolated from soil previously treated with the herbicides metolachlor and acetochlor. By 16S rRNA gene sequencing, we determined that SD1 is phylogenetically related to Enterobacter asburiae, while KD and K9 have divergent genomes that more closely resemble that of Enterobacter amnigenus. Decreased levels of lipid peroxidation were observed in SD1 and KD following treatment with 34Â mM metolachlor or 62Â mM acetochlor, respectively, indicating that both bacteria were able to adapt to an increase in ROS production. In the presence of 34Â mM metolachlor or 62Â mM acetochlor, all bacterial isolates exhibited increases in total catalase (CAT) activity (81% for SD1, 53% for KD and 59% for K9), whereas total SOD activity (assessed based on the profile and intensity of the bands) was slightly reduced when the bacteria were exposed to high concentrations of the herbicides (340Â mM metolachlor or 620Â mM acetochlor). This effect was due to a specific reduction in SOD IV (K9 and KD isolates) by 45% and 90%, respectively, and SOD V (SD1 isolate) isoenzymes by 60%. The most striking result was obtained in the SD1 isolate, where two novel isoenzymes of glutathione reductase (GR) that responded specifically to metolachlor were identified. In addition, acetochlor was shown to induce the expression of a new 57Â kDa protein band in the K9 and KD isolates. The bacteria isolated from the herbicide-contaminated soil exhibited an efficient antioxidant system response at herbicide concentrations of up to 34Â mM metolachlor or 62Â mM acetochlor. These data suggest a mechanism for tolerance that may include the control of an imbalance in ROS production versus scavenging. The data suggest that specific isoenzymes of CAT and GR could be involved in this herbicide tolerance mechanism.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Process Biochemistry - Volume 46, Issue 5, May 2011, Pages 1186-1195
Journal: Process Biochemistry - Volume 46, Issue 5, May 2011, Pages 1186-1195
نویسندگان
Paula F. Martins, Giselle Carvalho, Priscila L. Gratão, Manuella N. Dourado, Marcos Pileggi, Welington L. Araújo, Ricardo A. Azevedo,