Differential Responses of the Antioxidant System of Ametryn and Clomazone Tolerant Bacteria

Abstract

The herbicides ametryn and clomazone are widely used in sugarcane cultivation, and following microbial degradation are considered as soil and water contaminants. The exposure of microorganisms to pesticides can result in oxidative damage due to an increase in the production of reactive oxygen species (ROS). This study investigated the response of the antioxidant systems of two bacterial strains tolerant to the herbicides ametryn and clomazone. Bacteria were isolated from soil with a long history of ametryn and clomazone application. Comparative analyses based on 16S rRNA gene sequences revealed that strain CC07 is phylogenetically related to Pseudomonas aeruginosa and strain 4C07 to P. fulva. The two bacterial strains were grown for 14 h in the presence of separate and combined herbicides. Lipid peroxidation, reduced glutathione content (GSH) and antioxidant enzymes activities were evaluated. The overall results indicated that strain 4C07 formed an efficient mechanism to maintain the cellular redox balance by producing reactive oxygen species (ROS) and subsequently scavenging ROS in the presence of the herbicides. The growth of bacterium strain 4C07 was inhibited in the presence of clomazone alone, or in combination with ametryn, but increased glutathione reductase (GR) and glutathione S-transferase (GST) activities, and a higher GSH concentration were detected. Meanwhile, reduced superoxide dismutase (SOD), catalase (CAT) and GST activities and a lower concentration of GSH were detected in the bacterium strain CC07, which was able to achieve better growth in the presence of the herbicides. The results suggest that the two bacterial strains tolerate the ametryn and clomazone herbicides with distinctly different responses of the antioxidant systems.

Effects of Silver Nanoparticles on Multiple Drug-Resistant Strains of Staphylococcus aureus and Pseudomonas aeruginosa from Mastitis-Infected Goats: An Alternative Approach for Antimicrobial Therapy

“…P. aeruginosa and S. aureus showed higher GST activity by 60% and 50%, respectively (Figure 6B). Glutathione reductase (GR) and GST act in concert with the antioxidant compound GSH and play major roles in mediating the tolerance of a P. aeruginosa strain to various herbicides [78]. Similarly, Folsomia candida exposed to AgNPs displayed decreased levels of GSH and increased GST activity [79].…”

Ametryn removal by Metarhizium brunneum: Biodegradation pathway proposal and metabolic background revealed

“…Their use may minimize economic losses, and ensure the quality of crops and their protection against pests, weeds and diseases (Tejada et al, 2011;Peters et al, 2014). But, constant development of agricultural chemistry in the past decades has contributed to increasing pollution of the environment with these xenobiotics residues, especially surface water, groundwater and soil (Peters et al, 2014;Szewczyk et al, 2015;Długoński 2016). Triazines are chemical compounds belonging to the wider group of azines, characterized by a structure of a hetero-cyclic ring containing three unsaturated nitrogen atoms.…”

“…Ametryn is a systemic s-triazine herbicide absorbed by plant roots and leaves and characterized as a photosynthesis inhibitor. It is still in use in some countries in the farming of pineapples, soybean, corn, cotton, sugar cane or bananas to protect against broad-leaved weeds and grass (Grillo et al, 2011;Abigail at al., 2013;Peters et al, 2014). This xenobiotic has been classified by the Environmental Protection Agency (EPA) as a Class III herbicide moderately toxic to fish, large mammals and humans, while being highly toxic to crustaceans and molluscs (Navaratna et al, 2012).…”

“…Ametryn removal by Metarhizium brunneum: biodegradation pathway proposal and metabolic background revealed. Chemosphere 190: 174-183, DOI: 10.1016/j.chemosphere.2017 that when microorganisms (bacteria, fungi) are exposed to xenobiotics or their metabolites, a significant increase in reactive oxygen species (ROS) generation may occur and, consequently, this may induce an oxidative stress condition (Peters et al, 2014;Szewczyk et al, 2015;Soboń et al, 2016;Bernat et al, 2014). In this study, we examined ametryn biodegradation and, via a targeted metabolomics analysis, profiled free amino acids and a few other common small molecules.…”

Diferentes abordagens para o estudo da resposta de solanáceas ao Cd

“…Com relação a ultraestruturas, Gratão et al (2009) (GRATÃO et al, 2005). Além disso, alterações importantes da GR têm sido observadas em resposta ao estresse induzido por outros agentes estressores e em outros organismos, como por exemplo herbicidas e bactérias (MARTINS et al, 2011;PETERS et al, 2014).…”