Experiments were conducted to determine if pretreatment of cotton (Gossypium hirsutum L.) plants resulted in differential in vitro stabilities of nitrate reductase (NR) activity. Although NR activity declines markedly during the second half of the daily light period, in vitro NR stability is not modified by time of harvest. Phenylmethylsulfonylfluoride, iodoacetamide, and N-ethylmaleimide do not influence in vitro NR stability, suggesting that serine or sulfhydryl proteases are not responsible for in vitro lability of NR from cotton cotyledons.Imposition of water stress or artificial extension of the dark period lead to significant reductions in NR activity, but do not change in vitro NR stability.Dilution of a crude extract leads to increasing lability of NR; hence the marked instability of NR cannot be attributed to an inactivator which follows simple enzyme kinetics. Since in vitro NR activity is much more stable in presence of both NADH and NO(3) (-), substrate availability must be considered as a possible factor influencing in vivo NR stability.
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http://dx.doi.org/10.1104/pp.61.5.714 | DOI Listing |
Environ Sci Technol
January 2025
Marine Synthetic Ecology Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Observation and Research Station for Marine Ranching in Lingdingyang Bay, China-ASEAN Belt and Road Joint Laboratory on Mariculture Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Zhuhai 519082, China.
Plants can recruit microorganisms to enhance soil arsenic (As) removal and nitrogen (N) turnover, but how microbial As methylation in the rhizosphere is affected by N biotransformation is not well understood. Here, we used acetylene reduction assay, gene amplicon, and metagenome sequencing to evaluate the influence of N biotransformation on As methylation in the rhizosphere of , a potential As hyperaccumulator. was grown in mining soils (MS) and artificial As-contaminated soils (AS) over two generations in a controlled pot experiment.
View Article and Find Full Text PDFEnviron Pollut
January 2025
Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
Nitric oxide (NO) has garnered significant attention as a critical regulatory factor and signaling molecule in plant growth. However, the effects of microplastic pollution on the release of NO by algae have not been reported. Thus, in this study, the release of NO by Skeletonema costatum and Gymnodinium sp.
View Article and Find Full Text PDFFoods
January 2025
Unit for Food Hygiene and Technology, Centre for Food Science and Veterinary Public Health, Clinical Department for Farm Animals and Food System Science, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria.
Nitrite and nitrate in meat products may be perceived negatively by consumers. These compounds can react to form carcinogenic volatile N-nitrosamines. "Nitrite-free" (i.
View Article and Find Full Text PDFPlants (Basel)
January 2025
Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University, Huaian 223300, China.
Macrolide pollution has attracted a great deal of attention because of its ecotoxic effects on microalgae, but the role of phycospheric bacteria under antibiotic stress remains unclear. This study explored the toxic effects of erythromycin (ERY) on the growth and nitrogen metabolism of ; then, it analyzed and predicted the effects of the composition and ecological function of phycospheric bacteria on microalgae under ERY stress. We found that 0.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
School of Civil Engineering and Architecture, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China; Zhejiang-Singapore Joint Laboratory for Urban Renewal and Future City, Hangzhou 310023, China. Electronic address:
Despite growing attention to the environmental pollution caused by tire wear particles (TWPs), the effects of pristine and photoaged TWPs (P-TWPs and A-TWPs) and their TWP leachates (TWPLs; P-TWPL and A-TWPL) on key nitrogen removal processes in estuarine sediments remain unclear. This study explores the responses of the denitrification rate, anammox rate, and nitrous oxide (NO) accumulation to P-TWP, A-TWP, P-TWPL, and A-TWPL exposure in estuarine sediments, and assesses the potential biotoxic substances present in TWPLs. P-TWPs reduced the denitrification rate by 17.
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