Lead-Resistant Morganella morganii Rhizobacteria Reduced Lead Toxicity in Arabidopsis thaliana by Improving Growth, Physiology, and Antioxidant Activities
, Muther Mansoor Qaisrani 4, Muhammad Arshad 5, Muhammad Kashif Hanif 6, Roberto Mancinelli 7,* and Emanuele Radicetti 8
Round 1
Reviewer 1 Report
Comments to authors
MS#agriculture-1789611
The regular work entitled "Impact of lead-resistant Morganella morganii rhizobacterial strains on growth, chlorophyll contents and antioxidant activities of Arabidopsis plant under lead toxicity" by Naqqash et al., comprehensively explored role of Pb-resistant two Morganella morganiiABT3 and M. morganiiABT9 strains in improving growth, photosynthetic efficiency, and reduced lipid peroxidation in model plant Arabidopsis plant in response to Pb toxicity. In general, the author had a great effort on how an ecofriendly approach would be effective in phytoremediation to heavy metal contamination environments. However, I have some concerns that can help the authors to improve their current draft, such as:
Major concerns:
1. Introduction is shot. Especially discussed on the reasons of Pl-toxicity, impacts of plant physiology and soil environment, along with heavy metal remediation strategies. Unfortunately, statement lacks on how plants show protective/ detoxification mechanisms in response to Pb- metal detoxification. Why the author selected Arabidopsis plants for this study? So, these statements should be added in introduction section.
2. Discussion is one of the important parts of an article. “Our results are consistent with previous studies” repetition of such type of words is not always a good approach. Author should rework on discussion section. A good discussion contains-i) Principles and relationship which can be supported by the results; ii) emphasis on results and conclusions that agree and disagree with other work(s); iii) Avoiding the repetition of the results in discussion sections; iv) theoretical implications or short summary/findings/suggestions of each section(s) where applicable.
3. Materials and method sections are too short. Every section should be described precisely with updated references
4. SOD and CAT are involved in detoxification of stress metal induced formation of superoxide anion (O2−) by conversation of H2O2 and H2O and O2. Author determined CAT and POD, but it would be more insightful and will clarify the biochemical mechanism if the author determines SOD in this study.
Minor concerns:
1. All capital form should be avoided. The author should follow the guideline for scientific name and front for the title.
2. It would be more insightful if the author show the PCR validation of root samples for the 2 strains (Morganella morganiiABT3 and M. morganiiABT9) so that the reader can understand their involvement in improving plants traits under Pb-toxicity.
3. L144, Malondialdehyde (MDA) is one of the final products of polyunsaturated fatty acids peroxidation in the cells. An increase in free radicals causes overproduction of MDA. Malondialdehyde level is commonly known as a marker of lipid peroxidation. So, the MDA and lipid peroxidation are not same but MDA as an indicator for lipid peroxidation. The sub-title “Lipid peroxidation (MDA)” should be revised.
4. Section of “Antioxidant Enzymes estimation” is too short. Please extend it for each enzyme with proper references.
5. Please mentioned the significant level (P≤0.5 or P≤0.005 or P≤0.001) in statistical analysis section.
6. Fig. 6, label of parameter name overlaps the graphical scale. Please revise it.
7. Conclusion is not like an abstract. It should be revised with the evidence(s) of study, interpretation, and final suggestion(s).
8. Journal style must be follow for a arranging in reference.
Author Response
Reviewer 1
Comment 1:
Introduction is shot. Especially discussed on the reasons of Pl-toxicity, impacts of plant physiology and soil environment, along with heavy metal remediation strategies. Unfortunately, statement lacks on how plants show protective/ detoxification mechanisms in response to Pb- metal detoxification. Why the author selected Arabidopsis plants for this study? So, these statements should be added in introduction section.
Response: Thank you for your suggestion. The introduction has been revised regarding all the aspects suggested by the reviewer. Please see Lines 54-134 of the revised manuscript.
Comment 2:
Discussion is one of the important parts of an article. “Our results are consistent with previous studies” repetition of such type of words is not always a good approach. Author should rework on discussion section. A good discussion contains-i) Principles and relationship which can be supported by the results; ii) emphasis on results and conclusions that agree and disagree with other work(s); iii) Avoiding the repetition of the results in discussion sections; iv) theoretical implications or short summary/findings/suggestions of each section(s) where applicable.
Response: Thank you for your worthy comment. The discussion has been revised as suggested. Please see Lines 344-416 of the revised manuscript.
Comment 3:
Materials and method sections are too short. Every section should be described precisely with updated references
Response: Thank you for your suggestion. The section has been improved with their original references as suggested. Please see the revised manuscript.
Comment 4:
SOD and CAT are involved in detoxification of stress metal induced formation of superoxide anion (O2−) by conversation of H2O2 and H2O and O2. Author determined CAT and POD, but it would be more insightful and will clarify the biochemical mechanism if the author determines SOD in this study.
Response: Thank you for your insightful suggestion. During stresses, SOD catalyzes the removal of O2− by dismutating it into O2 and H2O2, and CAT converts the H2O2 into water and molecular oxygen (O2) both at intracellular space while peroxidases are the only enzymes that work in the extracellular space for scavenging H2O2. Therefore, one intracellular and one extracellular antioxidant was evaluated in this study. Moreover, due to the unavailability of NBT for SOD, we were unable to perform the experiment at that time. We will consider including this experiment in our further studies.
Comment 5:
All capital form should be avoided. The author should follow the guideline for scientific name and front for the title.
Response: Thank you for your suggestion. The capital form has been avoided as suggested. Please see the revised manuscript.
Comment 6:
It would be more insightful if the author show the PCR validation of root samples for the 2 strains (Morganella morganiiABT3 and M. morganiiABT9) so that the reader can understand their involvement in improving plants traits under Pb-toxicity.
Response: Thank you for your insightful suggestion. For doing the PCR validation of root samples, we need to set up the experiment again which would take 2 months. We apologize that we would not be able to perform this experiment at this moment. We would include this experiment in our further studies.
Comment 7:
L144, Malondialdehyde (MDA) is one of the final products of polyunsaturated fatty acids peroxidation in the cells. An increase in free radicals causes overproduction of MDA. Malondialdehyde level is commonly known as a marker of lipid peroxidation. So, the MDA and lipid peroxidation are not same but MDA as an indicator for lipid peroxidation. The sub-title “Lipid peroxidation (MDA)” should be revised.
Response: Thank you for your suggestion. The sub-title has been revised as per the suggestion. Please see Line 190-191 of the revised manuscript.
Comment 8:
Section of “Antioxidant Enzymes estimation” is too short. Please extend it for each enzyme with proper references.
Response: Thank you for your suggestion. The antioxidant section has been improved as suggested. Please see Line 200-221 of the revised manuscript.
Comment 9:
Please mentioned the significant level (P≤0.5 or P≤0.005 or P≤0.001) in statistical analysis section.
Response: Thank you for your suggestion. The significant level (P≤0.5 or P≤0.005 or P≤0.001) in statistical analysis section has been added as suggested. Please see Line 219-220 of the revised manuscript
Comment 10:
Fig. 6, label of parameter name overlaps the graphical scale. Please revise it.
Response: Thank you for your comment. Figure 6 has been revised as suggested. Please see the revised manuscript.
Comment 11:
Conclusion is not like an abstract. It should be revised with the evidence(s) of study, interpretation, and final suggestion(s).
Response: Thank you for your worthy comment. The conclusion section has been improved as suggested. Please see Lines 418-430 of the revised manuscript.
Comment 12:
Journal style must be follow for a arranging in reference.
Response: References have been modified as per the journal style. Please see the revised manuscript.
Reviewer 2 Report
This paper presents an interesting result of effects of lead-resistant Morganella morganii strains on growth, chlorophyll content and antioxidant activity of Arabidopsis thaliana under Lead stress. The quality of the article is well written. The detailed comments are as follows:
1. Regarding to the style of “Title”, it seems not the format for MDPI journals, please kindly use it according to the author guide. BTW, the correspondence email address in the first page was also missed.
2. In abstract, the presentation of specific key data in abstract is necessary to better support your study. Moreover, the major scientific contribution of the work should be mentioned here.
3. The relevance to “Agriculture” must be enhanced with the considerations of scope and readership of the Journal “Agriculture”. Please check the journal for its readership and related published work. It would be better to add a brief paragraph in the Introduction.
4. Materials and Methods section: This part was well written. The sub-sections need to be numbered, such as 2.1 Lead tolerance of rhizobacterial isolates. Moreover, if the commercial reagents/materials were applied, the product and/or company information should be mentioned.
5. Results: All the results were well presented. The Figures and Tables should be inserted into the text according to the author guide.
6. Conclusion: it is a brief summary of results or observations. It would be better to add the direction of further work.
7. Patents: This section can be deleted.
8. The legends and symbols of Figure 6 were hard to read (too small).
9. The text of the bottom of Figure 7 was too small.
Author Response
Reviewer 2
Comment 1:
Regarding to the style of “Title”, it seems not the format for MDPI journals, please kindly use it according to the author guide. BTW, the correspondence email address in the first page was also missed.
Response: Thank you for your suggestion. The title has been formatted according to the journal guidelines. Please see Line 2-4 of the revised manuscript. The email address has been added as suggested. Please see Line 21 of the revised manuscript.
Comment 2:
In abstract, the presentation of specific key data in abstract is necessary to better support your study. Moreover, the major scientific contribution of the work should be mentioned here.
Response: Thank you for your suggestion. The whole abstract has been revised as suggested by the reviewer. Please see Lines 23-51 of the revised manuscript.
Comment 3:
The relevance to “Agriculture” must be enhanced with the considerations of scope and readership of the Journal “Agriculture”. Please check the journal for its readership and related published work. It would be better to add a brief paragraph in the Introduction.
Response: Thank you for your suggestion. The paragraph regarding agriculture has been added as suggested by the reviewer. Please see Lines 55-63 of the revised manuscript.
Comment 4:
Materials and Methods section: This part was well written. The sub-sections need to be numbered, such as 2.1 Lead tolerance of rhizobacterial isolates. Moreover, if the commercial reagents/materials were applied, the product and/or company information should be mentioned.
Response: Thank you for your suggestion. The sub-sections have been numbered as suggested. All the chemicals/reagents were purchased from Sigma. This information has been added in the material and method section as suggested. Please see Lines 143-144 of the revised manuscript.
Comment 5:
Results: All the results were well presented. The Figures and Tables should be inserted into the text according to the author guide.
Response: Thank you for your suggestion. The Figures and Tables have been inserted according to the author’s guide. Please see the revised manuscript.
Comment 6:
Conclusion: it is a brief summary of results or observations. It would be better to add the direction of further work.
Response: Thank you for your worthy comment. The conclusion section has been improved as suggested. Please see Lines 418-430 of the revised manuscript.
Comment 7:
Patents: This section can be deleted.
Response: Thank you for your suggestion. The Patent section has been deleted as suggested. Please see the revised manuscript.
Comment 8:
The legends and symbols of Figure 6 were hard to read (too small).
Response: Thank you for your comment. Figure 6 has been improved as suggested. Please see the revised manuscript.
Comment 9:
The text of the bottom of Figure 7 was too small.
Response: Thank you for your suggestion. Figure 7 has been improved as suggested. Please see the revised manuscript.
Round 2
Reviewer 1 Report
Comments to authors
MS#agriculture-1789611-R1
The author revised partially of this manuscript. Therefore, this article still has several limitations, which must be addressed precisely before it further processing, such as:
1. It is crucial to determine SOD, CAT, and APX especially for detoxification related study. This is not a matter of their location in intracellular/extracellular space but it is a matter of their significance in detoxification process through metabolic reactions. So, there is a consequence among SOD, CAT and APX. The author did not determine SOD activity as I requested previously but noticed an inappropriate excuse. As the SOD is vital specially to check their response in metal/abiotic stress-induced oxidative stress condition. So, I am requesting once again to determine at least SOD activity, and add relevant texts in revised manuscript where in necessary.
2. Discussion section should be improved.
3. Title: I request to revise title by emphasizing suggestion(s)/insight(s) related to this work. “Effect of/”impact of” type of word (s) should be avoided from the title.
Author Response
Reviewer 1
Comment 1:
It is crucial to determine SOD, CAT, and APX especially for detoxification related study. This is not a matter of their location in intracellular/extracellular space but it is a matter of their significance in detoxification process through metabolic reactions. So, there is a consequence among SOD, CAT and APX. The author did not determine SOD activity as I requested previously but noticed an inappropriate excuse. As the SOD is vital specially to check their response in metal/abiotic stress-induced oxidative stress condition. So, I am requesting once again to determine at least SOD activity, and add relevant texts in revised manuscript where in necessary.
Response: Thank you for your suggestion. The SOD activity has been determined as suggested. The methodology, results and discussion has been added in the relevant sections. Please see the revised manuscript.
Comment 2:
Discussion section should be improved.
Response: Thank you for your comment. The discussion has been revised as suggested. Please see Lines 358-474 of the revised manuscript.
Comment 3:
Title: I request to revise title by emphasizing suggestion(s)/insight(s) related to this work. “Effect of/”impact of” type of word (s) should be avoided from the title.
Response: Thank you for your suggestion. The title has been modified as suggested. Please see the revised manuscript.
