Analytical approaches to study group omteractionsof azole pesticides with important biological active compounds
Ishak Kovač PhD thesis
The submitted thesis is based on four published scientific articles related to various aspects of the risk element stabilization in the contaminated soils, where the individual papers are clearly related to the individual main objectives of the work. Evidently, all the objectives stated were fulfilled and the main findings were successfilly published. The scientific value of the experiments was already assessed during the peer review process of the individual journals, and, because of the manuscripts were accepted, their value was sufficiently proven. The significant role of the student in the author’s teams of the presented articles is evident. Mr.
Kovač is twice listed as the first author, triple as the member of the author’s team. Moreover, all of the articles were published in high quality journals (Rapid Communications in Mass Spectrometry, 1st author; Journal of Chromatography, 1st author; Chemosphere 3rd author, Food Chemistry 2nd author; Environmental Toxicology and Pharmacology, member of the author’s team – in this case, the atricle is still under review, but its quality is comparable to the remaining manuscripts, thus, the acceptance of the text is expectable.
The whole text is written in precise and high quality English, with ocassional occurrence of typing errors, but they do not weaken the high quality of the whole work. For instance: in Abstract, LOD and LOQ values were probably mixed up; for tomato plants, both Solanum lycopersicum and old version Lycopersicum esculentum were used as latin names; at page 14, Solanum is written with a low case letter in the beginning, etc. I also recommend to use both common and scientific names of all the plants mentioned within the text.
Some particular comments to the individual sub-sections of the work:
Section 2 introduces the triazole fungicides, describes the main chemical structure and main physicochemical characteristics of triazole compounds, and their fate in the living organisms.
Generally, this section presents recent knowledge in the triazole research. The possible interactions of triazole compounds with the essential microelements are mentioned, as well.
As an important segment of the research, the present knowledge of the impact of triazoles on the expression of secondary metabolites is summarized, where the most important polyphenols are listed and described.
Questions to this section:
1. Page 17: the adverse effects of triazoles on various physiological and biochemical functions of the animal and human organisms are mentioned. Can you, please, present one or two examples of the triazole-induced physiological disfunctions (not related to P450 enzymes)?
2. Page 19: explain, please, in more details the exclusivity of Cu, Zn, and Fe chosen for the more detailed research
Section 3 presents the detailed description of the methodological approaches used for the research including explanation of the principles of the methods and their applications in the analyses of pesticides, triazole-chemical element chelates, and polyphenols characteristics.
A comment: In this case, please, specify the instrument types, and the main analytical conditions used in your investigations. In the present form, the methodology seems to be too general (of course, the methodology is detailed in the individual papers, but this section deserves at least the most important specifications, as well).
Section 4 represents the predominant part of the thesis, documenting the main results and their discussion. The section is clear and understandable, and introduces the main findings as related to the main objectives of the thesis. In the first part, the development and verification of the analytical method of the quantification of residues of triazole fungicides in tomato biomass.
The second part presents the application if the ESI-MS for the identification of the potential complexes of the triazole fungicides with selected essential micronutrients, in this case in model conditions as well as in the soil. The next part is focused on the study of potential interactions of the triazole fungicides with CYP450 enzymes in vitro. The last part of the Results and Discussion section is focused on the impact of triazole fungicides application on the growth parameters, yield characteristics, nutrient uptake, biochemical and physiological parameters of the tomato plants (including the secondary metabolites biosynthesis). The whole section is clearly presented, the individual experiments are well described, the results understandable, and the main findings are properly discussed. In the end, the main findings are summarized and the most important results highlighted in the section 5, i.e. short conclusion.
Questions and comments to this section:
1. Table 1: explain why the chosen doses of the TAFs were applied?
2. Table 4: there are different approaches to calculate LOD/LOQ. Which formula was used in this case?
3. Page 49: explain in detail why „the behavior of the coordination species in the gas- phase is sot allways the same as in the liquid phase“
4. Table 9: how were the bioavailable proportions of the microelements in soils determined?
5. Page 52: only comment: the role of microelements in plants was already described on the Section 2, some statements are already mentioned above.
6. Page 52: Are there any evidences documenting the response of the plant microelement on the application of TAFs?
7. Figure 12: a comment: letters presenting the significant differences among the variants are missing (although metioned in the figure caption)
8. Figure 12: ocassionally, the activities of aromatase indicate stimulation. Any explanation of this phenomenon?
9. Figure 14: the results indicate that the soil application of TAFs reduced biomass yield of stems and leaves. Any explanation? And what about roots?
10. Page 64: Specify which components of the soil microbiota are predominantly affected by TAFs and how is his adverse effect connected to the tomato plant growth?
Generally, the thesis contains promising results based on the recent knowledge, where adequate methodology of the individual experiments was applied, and the scientific merit of the study is undeniable. Thus, the thesis is ready for the public defense. As a conclusion, the PhD thesis of Ishak Kovač present original research results and I recommend that the candidate is awarded the doctoral degree, if the thesis will be successfully defended.
Prague, March 3rd, 2023 Jiřina Száková
Department of Agro-environmental Chemistry and Plant Nutrition, University of Life Sciences in Prague
