Abstract
The study reports the response to herbicide of the 2,4-dichlorophenoxyacetic acid (2,4-D)–degrading fungal strain Umbelopsis isabellina. A comparative analysis covered 41 free amino acids as well as 140 lipid species of fatty acids, phospholipids, acylglycerols, sphingolipids, and sterols. 2,4-D presence led to a decrease in fungal catalase activity, associated with a higher amount of thiobarbituric acid-reactive substances (TBARS). Damage to cells treated with the herbicide resulted in increased membrane permeability and decreased membrane fluidity. Detailed lipidomic profiling showed changes in the fatty acids composition such as an increase in the level of linoleic acid (C18:2). Moreover, an increase in the phosphatidylethanolamine/phosphatidylcholine ratio was observed. Analysis of fungal lipid profiles revealed that the presence of 2,4-D was accompanied by the accumulation of triacylglycerols, a decrease in ergosterol content, and a considerable rise in the level of sphingolipid ceramides. In the exponential phase of growth, increased levels of leucine, glycine, serine, asparagine, and hydroxyproline were found. The results obtained in our study confirmed that in the cultures of U. isabellina oxidative stress was caused by 2,4-D. The herbicide itself forced changes not only to membrane lipids but also to neutral lipids and amino acids, as the difference of tested compounds profiles between 2,4-D—containing and control samples was consequently lower as the pesticide degradation progressed. The presented findings may have a significant impact on the basic understanding of 2,4-D biodegradation and may be applied for process optimization on metabolomic and lipidomic levels.
Highlights
Auxin-like 2,4-dichlorophenoxyacetic acid (2,4-D) is commonly used to control weeds among cereal crops such as corn and wheat [1]
Modifications in fungal activity were observed both for the exponential phase of growth, when most of the added xenobiotic was present in the culture (>80% of the initial content), and for the stationary phase of growth, after >70% of the added herbicide was metabolized
The present study demonstrates that 2,4-D significantly disturbs lipid and amino acid metabolisms in U. isabellina
Summary
Auxin-like 2,4-dichlorophenoxyacetic acid (2,4-D) is commonly used to control weeds among cereal crops such as corn and wheat [1]. The toxic effects of 2,4-D have been studied using microbial models of Saccharomyces cerevisiae [8, 9], which are not able to metabolize this herbicide. It seems that the liposoluble form of this toxic compound affects the spatial organization of the membrane and impairs its function as a permeability barrier [8, 9]. The present study may provide valuable information about the promotion of oxidative stress in this herbicide-metabolizing fungus in terms of lipid composition and the concentration of free amino acids. The reactive oxygen species (ROS) and reactive nitrogen species (RNS) generated within cells were detected using a confocal laser scanning microscopy (CLSM) technique
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
