Effects of Exogenous Melatonin on the Growth and Physiological Characteristics of Ginkgo biloba L. under Salinity Stress Conditions
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsI consider the topic of the manuscript important: the increase in soil salinity and the effects of secondary salinization in an urban environment is a research area that deserves special attention. The plant species chosen for the model experiment is also a good choice, since Ginkgo biloba L. and its varieties are some of the most commonly planted tree taxa today, which tolerates urban conditions well in many respects. Plants planted as roadside trees are exposed to the harmful effects of NaCl-containing agents used for snow melting.
The authors chose the methods used during the experiment extremely carefully and ensured the sufficient depth of the research with the large number of examined parameters. The only shortcoming of the design of the experiment is that the number of sample elements used per treatment is low (5 repetitions). The statistical support of the findings could have been further increased by examining at least 15 or 20 plants per treatment. The explanatory texts for Tables 1, 2, Figures 1, 2, 3, 4, 5, 6 need to be corrected: N1, N2, N3 actually do not denote melatonin, but NaCl treatments . The presentation of the results of the extremely complex experiment must have been a big challenge for the authors due to the many variables and changes over time, but in my opinion, they managed to find an appropriate way to represent the data. I recommend clarifying the meaning of the different shades of color for the control (CK) treatment.
Author Response
Dear Editors and Reviewers,
Greetings! First, I extend my heartfelt gratitude for the valuable comments provided during the review of "Effects of Exogenous Melatonin on the Growth and Physiological Characteristics of Ginkgo biloba L. under Salinity Stress Conditions" (Manuscript ID: horticulturae-2785526). Your expert suggestions are crucial to the enhancement and refinement of this manuscript. I have carefully considered each remark and have accordingly made thorough revisions to the text. The specific amendments and corresponding responses are as follows:
Modification Point 1: The experimental method was appropriate, ensuring research depth with multiple parameters. The main limitation was the small sample size (5 repetitions) for each treatment. It is suggested to increase the number of plants to 15-20 per treatment to enhance statistical support.
Author's Response: Thank you for the thorough review and valuable suggestions regarding our experimental design. We have carefully considered your advice about increasing the sample size to enhance statistical support. Our experiment was conducted under strict control with uniform 4-year-old Ginkgo biloba seedlings, ensuring consistency and representativeness. We simulated 13 different combinations of salt concentration and melatonin (MT) levels, each with 5 repetitions. Despite the limited sample size, our current experimental conditions sufficiently support our conclusions. Considering practical aspects of resource and management, we believe that 5 repetitions are a pragmatic choice. However, we acknowledge your recommendation and plan to increase the number of repetitions in future research to improve the quality and statistical rigor of our experiments.
Modification Point 2: It is necessary to correct the explanatory texts for Tables 1 and 2 and Figures 1 to 6: N1, N2, N3 actually denote NaCl treatments, not melatonin.
Author's Response:Thank you for the attention to errors in the manuscript's tables and figures. Upon review, corrections have been made to Tables 1, 2, and Figures 1 to 6. The labels N1, N2, and N3 were mistakenly used to indicate melatonin instead of their actual reference to different concentrations of NaCl. This oversight in editing has been rectified, and all relevant notations and descriptions have been updated to accurately reflect the NaCl stress concentrations used in the experiments: 50, 100, 200 mmol·L^-1. The author thanks the reviewer for their meticulous review and valuable advice and commits to increased vigilance in future research and writing to prevent similar errors.
Additionally, the modifications suggested in the revised draft have been made as per your request, and we invite you to review them. We are open to further suggestions and committed to making any necessary changes. Once again, thank you for your valuable feedback on our manuscript. Wishing you every success and happiness in life!
Respectfully,
Zhou Dan, Li Meng, Wang Xiujun, Li Haiyan, Li Zihang, and Li Qingwei
December 30, 2023
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsDear Prof
Horticulturae Editorial Office
Please find enclosed my revision of the manuscript ID:
horticulturae-2785526
Manuscript Title:
Effects of Exogenous Melatonin on the Growth and Physiological Characteristics of Ginkgo biloba L. under Salinity Stress Conditions
The paper suffers some drawbacks that need major revision. It is questionable whether represents any significant contribution to the field. In any case, I highly encourage the authors to carefully review point by point to clarify some issues and eventually improve the manuscript. Please see the attachment file
There are some problems with this manuscript
1. Some sentences need a reference/s
2. The introduction lacks an in-depth presentation of data available in the literature that would provide the basis to justify the importance of the work.
3. Please indicate the centrifugation as xg or indicate the diameter of a rotator, size of tubes. ... etc
4. Please do not start any sentence with an abbreviation. Authors should abbreviate at first mention and follow this abbreviation in the entire manuscript
5. Please indicate the methods for maintaining actual salinity levels throughout the experimental period, what about saline accumulation in the soil.
6. Please introduce the physical and chemical analysis of experimental soil
7. Concerning RWC the equation introduced is for water content not relative water content. The RWC used fresh, turgid and dry weights, please revise
8. Be accurate RWC is not Antioxidant substances (Title 2.3) so please change the title into physio-biochemical attributes for example
9. I don't understand to use Duncan's multiple range tests. Why did you use this test? The reason why is not clear for me. Many statisticians pointed out the problem in this test: Type I error rate is high (i.e. Ryan 1959; Scheffe 1959; Petrinovich and Hardyck 1969…….
10. Be accurate, please revise all tables or figures for letters for example in table, Ground Diameter how 0.168a; 0.121b, 0.094a it is a big problem!!!!!!!!!!!!
11. The figure must be changed it is very bad. Additionally, add the letters in all figures
12. For the first time for me to seed in healthy plants chlorophyll b is higher than chlorophyll a !!!!!!!!!!!!!! It is a big problem please recheck your equation it means the plant enter to the last stage of senescence
13. the discussion is very poor and needs to be rewritten
14. In the conclusion section, the authors fail to highlight the importance of this study and what readers could learn from this study that is different from others. The conclusion also does not summarize the hypothesis about the major mechanisms. Please make this summarizing, because, the main aim of any scientific manuscript, is not only to describe the effect but also to make suggestions about mechanisms. If we know the mechanisms, we can improve or reinforce the influences. If we have no information about the mechanism, we can make mistakes. Please rewrite with concentration indicating the most important finding or recommendation
Yours truly
Comments for author File: Comments.pdf
Minor editing of English language required
Author Response
Revision Explanation 2
Dear Editors and Reviewers,
Greetings! First, I extend my heartfelt gratitude for the valuable comments provided during the review of "Effects of Exogenous Melatonin on the Growth and Physiological Characteristics of Ginkgo biloba L. under Salinity Stress Conditions" (Manuscript ID: horticulturae-2785526). Your expert suggestions are crucial to the enhancement and refinement of this manuscript. I have carefully considered each remark and have accordingly made thorough revisions to the text. The specific amendments and corresponding responses are as follows:
Modification Point 1: Some sentences require citation of sources.
Author's Response: Thank you for highlighting the absence of necessary citations in certain sentences of the manuscript. We have thoroughly reviewed the paper and made extensive revisions to un-cited sentences, specifically lines 39-69 and 89-92. Now, all data, theoretical views, and key information are properly cited with relevant references, ensuring academic rigor and completeness of the manuscript. Your careful review and valuable suggestions greatly contribute to improving the quality of our paper.
Modification Point 2: The introduction lacks a detailed presentation of available data in the literature, which should be used to demonstrate the importance of the work.
Author's Response: Thank you for pointing out the inadequacy in the introduction regarding an in-depth presentation of literature data. Following your suggestion, we have expanded and improved the introduction, now including a more comprehensive literature review, particularly around recent advancements, key findings, and significant data relevant to our research topic, as detailed in lines 53-69 of the manuscript. These additions not only highlight the current research gaps but also illustrate how our work addresses these gaps and its potential impact in the field. Your guidance is vital in enhancing the depth and scope of our paper, ensuring accurate recognition and understanding of our research in the academic community.
Modification Point 3: Please specify the exact conditions for centrifugation, such as xg, rotor diameter, tube size, etc.
Author's Response: Thank you for your valuable suggestion regarding the specifics of centrifugation. Indeed, detailed centrifugation conditions are crucial for replicating experiments and ensuring accuracy of results. In the original manuscript, we did not provide sufficient details about these conditions. We have now revised the methods section, specifically for the measurement of leaf SOD activity, to include the critical information of 10000 xg, ensuring that readers can accurately replicate the experimental conditions. This modification can be found in line 215 of the manuscript. Your careful guidance greatly contributes to enhancing the quality and scientific rigor of our paper.
Modification Point 4: Please avoid starting sentences with acronyms. Authors should use the full term when first mentioned and maintain consistency throughout the manuscript.
Author's Response: Thank you for your meticulous review and valuable advice regarding the manuscript format, particularly about the use of acronyms. We agree with your guidance on avoiding acronyms at the beginning of sentences and defining them at their first occurrence for clarity and consistency. Following your suggestions, we have thoroughly reviewed the manuscript to ensure that every acronym is properly introduced and consistently used throughout the text. We have also adjusted sentence structures to avoid starting with acronyms. Your feedback is highly valued as it significantly contributes to enhancing the quality and rigor of our paper. Thank you for your detailed guidance and helpful suggestions.
Modification Point 5: Please explain how actual salinity levels were maintained during the experiment, and how soil salinity accumulation was monitored.
Author's Response: Thank you for your advice regarding the maintenance and monitoring of soil salinity levels during the experiment. The information you provided is crucial for understanding the experimental design and soil salinity management. In our experiment, we took the following steps to maintain and monitor soil salinity levels:
(1) Gradual addition of salt concentration: Starting from July 8, 2020, we gradually increased the concentration of NaCl by 50 mmol·L-1 each day to reach the predetermined salinity level. This approach was aimed at simulating the gradual accumulation of salts in a natural environment and avoiding salt shock effects.
(2) Regular saline irrigation: Once the predetermined salinity level was reached, we conducted weekly saline irrigation for the treatment groups at the same concentration (0.5 liters per pot) to ensure that the soil's salinity remained at the required experimental level. The control group received irrigation with the same volume of plain water.
(3) Prevention of salt loss: We placed trays at the bottom of the pots to collect leachate, reducing salt loss and controlling the accumulation of salts in the soil.
(4) Regular monitoring and adjustment: During the experiment, we regularly monitored soil salinity levels by collecting samples and measuring soil conductivity, allowing us to monitor and adjust soil salinity to ensure consistency throughout the experiment.(Already addressed in the paper)
(5) Recording and analyzing leachate: We analyzed the salt content in the collected leachate to assess and record the accumulation of salts in the soil.
Through these methods, we were able to effectively control and monitor soil salinity levels during the experiment, ensuring the consistency and reliability of the experimental conditions. We have added these critical experimental details to the revised manuscript to provide a more comprehensive experimental description and ensure the reliability of our results. Once again, we appreciate your guidance and suggestions.
Modification Point 6: Please introduce the physical and chemical analysis of the experimental soil.
Author's Response: Thank you for suggesting a detailed analysis of the soil's physical and chemical properties. The soil used for the experiment is a soil mixture composed of peat, perlite, and vermiculite in a ratio of 3:2:1 to ensure consistency. The soil was analyzed for organic carbon, total nitrogen, and total phosphorus, indicating fertility status. Additionally, field water-holding capacity and bulk density were measured, providing insights into soil structure and moisture retention. The initial soil data supported the experiment, focusing on the effects of exogenous melatonin under salt stress on Ginkgo biloba L. Future studies might consider more comprehensive soil analyses.
Modification Point 7: Regarding the Relative Water Content (RWC), the formula you provided is for water content rather than relative water content. RWC should be calculated using fresh weight, turgid weight, and dry weight. Please make the necessary corrections.
Author's Response: Thank you for pointing out the error in the calculation of Relative Water Content (RWC) in our paper. We have corrected the RWC formula to accurately reflect the moisture status of plant tissues: RWC = [(Fresh Weight - Dry Weight) / (Turgid Weight - Dry Weight)] × 100%. This involves measuring fresh weight, turgid weight, and dry weight of plant samples. We apologize for the oversight and appreciate your guidance on this critical error. This correction enhances the accuracy and reliability of our results. Thank you again for your expert advice.
Modification Point 8: It is correctly noted that RWC is not an antioxidant substance (as titled in section 2.3). Therefore, it is suggested to change the title to something more appropriate like "Physiological and Biochemical Characteristics."
Author's Response: Thank you for pointing out the inaccuracy in the title of section 2.3 of our paper. As you correctly noted, Relative Water Content (RWC) is not an antioxidant substance but a physiological and biochemical characteristic of plants. Based on your suggestion, we have changed the section title from "Antioxidant Substances" to "Physiological and Biochemical Characteristics." We appreciate your careful review and constructive suggestions, which have helped to enhance the accuracy and professionalism of our manuscript.
Modification Point 9: The Reason for Using the Duncan Multiple Range Test.
Author's Response: Thank you for your query regarding our use of Duncan's multiple range test. We acknowledge your concerns about the potential for increased Type I errors. Our choice was based on the test's ability to effectively identify significant differences between treatments following significant one-way ANOVA results. Despite its risk of higher Type I errors, our balanced and stable dataset minimizes this concern. We also employed additional verification methods, including data checks and comparison with other statistical tests like Tukey's HSD, to balance sensitivity and overall reliability. We appreciate your professional advice and will consider more stringent statistical methods in future research.
Modification Point 10: Please accurately revise all letter markings in all tables or figures.
Author's Response: Thank you for pointing out issues with letter markings in tables and figures. All letter markings have been removed from the tables, and the author sincerely apologizes for any confusion caused and appreciates the meticulous review. This revision will enhance the quality of the paper, ensuring accurate interpretation of the research results. Thank you again for your professional guidance and valuable feedback.
Modification Point 11: The graphics need to be revised; please add letter markings to all figures.
Author's Response: Thank you for your feedback on the figures in our paper. We chose stacked bar charts considering the complexity of the experimental data and their ability to clearly display changes in various parameters over time. Our experimental design involves multiple variables and repeated measurements, and this format allows for comparison across time and treatments. However, due to the large number of treatment combinations, labeling each with a letter might overly complicate the figures. If needed, we could consider providing raw data and markings in an appendix. Our goal is to balance data accuracy and readability for effective scientific communication. Thank you for your thorough review and valuable suggestions.
Modification Point 12: Review the observation that chlorophyll b is higher than chlorophyll a, and recheck your equations, as this might indicate that the plants are in the final stages of aging.
Author's Response: Thank you for pointing out the issue in the report regarding the higher content of chlorophyll b compared to chlorophyll a. Upon rechecking the experimental data, we found that this problem arose due to the confusion between chlorophyll a and chlorophyll b during the process of creating graphs. We have rectified this and ensured the accuracy of the data. This correction is crucial for accurately interpreting the experimental results. Additionally, we have rechecked other data to ensure the credibility and accuracy of the entire experimental dataset. Once again, we appreciate your review and valuable suggestions.
Modification Point 13: The discussion section needs to be rewritten.
Author's Response: Thank you for the valuable feedback on the discussion section of the manuscript. To enhance its depth and breadth, the discussion has been reconstructed following the suggestions, with detailed analysis of the data, clarification of the biological significance of the findings, comparison with a wide range of related literature, and discussion of the study's limitations and potential biases. Additionally, future research directions based on current results have been proposed. The author commits to further improvements to ensure the quality and contribution of the research.
Modification Point 14: The reviewer suggests that the conclusion section lacks emphasis on the study's significance and its distinct learning points compared to other research. It also misses a summary of the main mechanism hypotheses. They advise a focused rewrite to highlight key findings and recommendations, emphasizing the importance of proposing mechanisms for better understanding and potential improvement. Understanding mechanisms is crucial to avoid errors and enhance impacts.
Author's Response: Thank you for the thorough review and has revised the conclusion to emphasize the study's significance and novelty. The revision addresses melatonin's role in plant salt tolerance mechanisms, highlighting the effectiveness of the 0.02 mmol·L^-1 MT treatment in reducing NaCl stress in Ginkgo biloba seedlings and the potential risks of the 0.5 mmol·L^-1 MT treatment. The revision also discusses key physiological indicators like Pn, Tr, ETR, Fo, and SOD in assessing salt stress, suggesting mechanisms to enhance plant salt tolerance. Additionally, the study's unique contribution to addressing the impact of de-icing agents on Ginkgo biloba street trees and expanding their planting area is emphasized.
Additionally, the modifications suggested in the revised draft have been made as per your request, and we invite you to review them. We are open to further suggestions and committed to making any necessary changes. Once again, thank you for your valuable feedback on our manuscript. Wishing you every success and happiness in life!
Respectfully,
Zhou Dan, Li Meng, Wang Xiujun, Li Haiyan, Li Zihang, and Li Qingwei
December 30, 2023
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsDear Prof
The manuscript has been sufficiently improved to warrant publication in Horticulturae.
yours
Comments on the Quality of English LanguageMinor editing of English language required
