Effect of Simulated Organic–Inorganic N Deposition on Leaf Stoichiometry, Chlorophyll Content, and Chlorophyll Fluorescence in Torreya grandis

Round 1

Reviewer 1 Report (New Reviewer)

The manuscript describes the effects of simulated organic–inorganic N deposition on leaf stoichiometry, chlorophyll content, and chlorophyll fluorescence in Torreya grandis. The authors conclude that Torreya grandis plants performed best at an ON/IN ratio of 3/7, with the highest values of chlorophyll-a, total chlorophyll, maximum photochemical efficiency, and photosynthetic performance index. Thus, both ON and IN types should be considered when assessing the responses of plant growth to increasing N deposition in the future. In addition, the authors find out the leaf P content increased significantly after treatment. The results suggest that the homeostasis of element stoichiometry under nitrogen deposition is very important for the growth of T. grandis. Thus, the topic is of interest and the obtained results have basic level of novelty. There are, however some inconsistencies that require further explanations or changes prior to publication in Horticulturae.

1.      The growth performance of Torreya grandis seedlings should be provided. Because the authors mentioned that the seedlings in N2 group showed the better growth compared to control in line 288-290.

2.      The utilization of organic N is related to various factors such as microbial activity. The microbial activity is correlated to C:N ratio. If the authors could provide the result of C:N in soils after treatments, the research will be more valuable.

3.      The sources of IN and ON should be mentioned in materials and methods.

4.      The resolution of Figure 4 is too low.

5.      There are typos “et al.” in line 220.

6.      The format of references is inconsistent such as line 343-344, 349, 371, and so on.

Minor editing of English language required.

Author Response

1. The growth performance of Torreya grandis seedlings should be provided. Because the authors mentioned that the seedlings in N2 group showed the better growth compared to control in line 288-290.

R: Thank you. We made some changes about this sentence.

2. The utilization of organic N is related to various factors such as microbial activity. The microbial activity is correlated to C:N ratio. If the authors could provide the result of C:N in soils after treatments, the research will be more valuable.

 R: Thank you for your comments. It would be very interesting to test the response of the soil after treatment, however we do not have the relevant data in this paper, but we will conduct the relevant research in the future and also added some discussion about it in this paper.

3. The sources of IN and ON should be mentioned in materials and methods.

R: Added as suggested.

4. The resolution of Figure 4 is too low.

R: Changed as suggested.

5. There are typos “et al.” in line 220.

R: Changed as suggested.

6. The format of references is inconsistent such as line 343-344, 349, 371, and so on.

R: Changed as suggested.

Reviewer 2 Report (Previous Reviewer 4)

MS is ready to be published

Author Response

Thank you.

Reviewer 3 Report (Previous Reviewer 3)

The authors have largely fulfilled the initial comments and corrections requested for the manuscript. I believe that the manuscript can be published in this form.  

Author Response

Thank you for your comments.

Reviewer 4 Report (Previous Reviewer 1)

-        This paper correspond for scope of journal.

-          The title corresponds to the content of the paper. 

- This study represents a significant contribution to knowledge about effects of the different proportion of mixed addition of ON and IN on the LF, chlorophyll content, and chlorophyll fluorescence of Torreya. grandis seedlings.

-  The main question of paper  addressed to establish  specificity of adaptation of Torreya. grandis seedlings on changes in environment by maintaining the homeostasis of element stoichiometry and the  plasticity of PSII activity through study effects of the different proportion of mixed addition of ON and IN on the physiology  in aim of assessing the responses of photosynthesis and plant growth to globally increasing N deposition from a long-term perspective.

-    The aim of research  is clearly and fully pointed  in abstract. Author need pointed out  aim of study  on the end of chapter of Introduction as particular paragraph .

 -          Key words are appropriate.

 -          Scientific methodology is applied correctly for this type of study.

-          Results are clearly presented and discussed.

 -          Tables, figures, pictures are clear.

 -          The conclusions are clear and based on research results

 -          Manuscript is acceptable after minor corrections!

Remarks:

From line 84 to 85. Should be little bit change and write: The aim of this investigation was study  the effect of simulated organic–inorganic N deposition on  LF, chlorophyll content, and chlorophyll fluorescence of T. grandis.

This sentence with defined aim of study should be the last paragraph on the end of chapter of introduction.The text of aim and text of defined working hypotheses must be presented separately and in an appropriate place in the structural concept of the scientific work,

From line 85 to 90. Part of paragraph text  need move after chapter Material and methods and befor chapter Results under the new  title WORKING HYPOTHESIS: “ For this study two working hypotheses are defined  (1) Treatments with ON/IN addition will change the LF and  growth of T. grandis. (2) Moderate ON/IN ratios will promote growth of T. grandis, and  there will be a correlation between LF, chlorophyll content, and chlorophyll fluorescence  parameters. Testing these hypotheses will provide novel insight into understanding the  response strategies of plants under the background of increasing N deposition.

or authors can include working hypotheses in the introduction before the paragraph about the research objective without distinguishing the working hypothesis title.

Author Response

R: Thank you. Changed as suggested.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

-          This paper correspond for scope of journal. 

-         The title corresponds to the content of the paper. 

-          This study represents a significant contribution to knowledge about effects of the different proportion of mixed addition of ON and IN on the LF, chlorophyll content, and chlorophyll fluorescence of Torreya. grandis seedlings.

-          The main question of paper  addressed to establish  specificity of adaptation of Torreya. grandis seedlings on changes in environment by maintaining the homeostasis of element stoichiometry and the  plasticity of PSII activity through study effects of the different proportion of mixed addition of ON and IN on the physiology  in aim of assessing the responses of photosynthesis and plant growth to globally increasing N deposition from a long-term perspective.        

-   - The aim of research  is clearly and fully pointed  in abstract. Author need pointed out  aim of study  on the end of chapter of Introduction as particular paragraph .

 -          Key words are appropriate.

 -          Scientific methodology is applied correctly for this type of study.

-          Results are clearly presented and discussed.

 -          Tables, figures, pictures are clear.

 -          The conclusions are clear and based on research results

 -          Manuscript is acceptable after minor corrections!

Author Response

Dear Editor,

We sincerely thank the reviewers for their comments on our manuscript. We have carefully revised the manuscript according to the comments of reviewers. In our point-by-point responses below, reviewers’ comments are in BLACK and our responses are in BLUE. In the revised manuscript, modifications are done with Track Changes. We hope the new manuscript will meet your journal’s standard. We look forward to hearing from you soon.

Thank you again for your time and consideration.

Yours sincerely,

Yang Liu

-Reviewer 1

1. This paper correspond for scope of journal.

- The title corresponds to the content of the paper.

- This study represents a significant contribution to knowledge about effects of the different proportion of mixed addition of ON and IN on the LF, chlorophyll content, and chlorophyll fluorescence of Torreya. grandis seedlings.

- The main question of paper addressed to establish  specificity of adaptation of Torreya. grandis seedlings on changes in environment by maintaining the homeostasis of element stoichiometry and the  plasticity of PSII activity through study effects of the different proportion of mixed addition of ON and IN on the physiology  in aim of assessing the responses of photosynthesis and plant growth to globally increasing N deposition from a long-term perspective.

R: Thank you.

2. - The aim of research is clearly and fully pointed in abstract. Author need pointed out aim of study on the end of chapter of Introduction as particular paragraph.

R: Changed as suggested.

4. - Key words are appropriate.

 - Scientific methodology is applied correctly for this type of study.

- Results are clearly presented and discussed.

 - Tables, figures, pictures are clear.

 -The conclusions are clear and based on research results

 - Manuscript is acceptable after minor corrections!

R: Thank you for your advice.

Reviewer 2 Report

Comments for author File: Comments.pdf

Author Response

-Reviewer 2#

1. Literature research and reference to previous studies should be extended

R: Done as suggested.

2. The discussion should be revised, to improve the way in which the new data is set into context to published data.

R: Done as suggested.

3. It is necessary to include a chemical analysis of the soil after the tests have been completed. It is important to see if there have been any changes.

R: Thank you. In fact, N deposition would affect soil properties, which is largely explored by previous studies. Although soil samples were not collected in this study, we added such discussion according to your suggestion: “Previous studies of IN N deposition have shown that IN could inhibit plant growth due to the soil properties negatively affected by IN N deposition [7,43]. For example, Zhang et al. [43] showed that IN N deposition decreased soil pH, available N, P and K in Torreya grandis plantations. However, compared with CK, treatments with a higher ON:IN ratio significantly promoted leaf P content and photosynthetic performance of T. grandis. These results indicate that exogenous N input changes the phosphorus concentration of T. sinensis, and the primary reason might be the change of soil available phosphorus content, and the second reason might be the change of plant phosphorus absorption capacity and phosphorus use efficiency [13].”.

4. There are biofertilizers on the market that contain nitrogen fixers. It's interesting to see what happens when something like that is added. Also, such fertilizers are ecologically justified and contribute to sustainability.

R: Thank you. Since this study focuses on N deposition, which is different from N fertilization, we mainly summarized findings from N-deposition studies.

Reviewer 3 Report

First of all, I would like to thank the authors for writing a clear, understandable, and fluent article. My suggestions and opinions;

- Expanding the summary part of the article and mentioning the information about the results will bring the reader a little closer to the subject

- The conclusion part will be expanded a little and will contribute to emphasizing the positive results of the study.

- Finally, when the similarity report of the study is examined, a rate of 30% is seen, which is relatively high for an original article and the relevant parts of the manuscript should be revised.

The study is not very different and original in terms of methods and applications, apart from the "Liu, Yang and Chen, Pei and Chen, Shuhui and Hang, Ziying and Jin, Songheng, Simulated Organic–Inorganic Nitrogen Deposition Changes the Growth Rate, Leaf Stoichiometry, and Phenolic Content of Cyclocarya Paliurus. Available at SSRN: https://ssrn.com/abstract=4442101 or http://dx.doi.org/10.2139/ssrn.4442101" manuscript published by the authors before and plant material. In this sense, it cannot be said that he added much innovation to science. However, it can be considered a new material for young scientists considering working on the subject.

Author Response

Dear Editor,

We sincerely thank the reviewers for their comments on our manuscript. We have carefully revised the manuscript according to the comments of reviewers. In our point-by-point responses below, reviewers’ comments are in BLACK and our responses are in BLUE. In the revised manuscript, modifications are done with Track Changes. We hope the new manuscript will meet your journal’s standard. We look forward to hearing from you soon.

Thank you again for your time and consideration.

Yours sincerely,

Yang Liu

-Reviewer 3

1. - Expanding the summary part of the article and mentioning the information about the results will bring the reader a little closer to the subject.

R: Changed as suggested.

2. - The conclusion part will be expanded a little and will contribute to emphasizing the positive results of the study.

R: Changed as suggested. Thank you for suggestion.

3. - Finally, when the similarity report of the study is examined, a rate of 30% is seen, which is relatively high for an original article and the relevant parts of the manuscript should be revised.

R: Changed as suggested.

Reviewer 4 Report

After reviewing your manuscript (MS) some considerations arised:

- Keywords: do not repeat the same words as in the title. You can excel the importance of P by adding in the kw

- L 137. Erase "generally": it would mke more sense

- why did you focus on the relationship with P and not with other elements like K, ten times more concentrated in the leaves than P? Maybe you can run other correlation analyses to point out the higher P importance? you can add a sentence in the comclusions explaining your choice

Author Response

Dear Editor,

We sincerely thank the reviewers for their comments on our manuscript. We have carefully revised the manuscript according to the comments of reviewers. In our point-by-point responses below, reviewers’ comments are in BLACK and our responses are in BLUE. In the revised manuscript, modifications are done with Track Changes. We hope the new manuscript will meet your journal’s standard. We look forward to hearing from you soon.

Thank you again for your time and consideration.

Yours sincerely,

Yang Liu

-Reviewer 4

1. - Keywords: do not repeat the same words as in the title. You can excel the importance of P by adding in the kw.

R: Changed as suggested.

2. - L 137. Erase "generally": it would make more sense

R: Done as suggested.

3. - why did you focus on the relationship with P and not with other elements like K, ten times more concentrated in the leaves than P? Maybe you can run other correlation analyses to point out the higher P importance? you can add a sentence in the conclusions explaining your choice

R: Thank you for your advice. We have added a sentence into the conclusions according to your suggestion: “The variation of P content in plants under N addition has caused much attention to researchers. Our results indicated that the leaf P concentration was positively correlated with Chl, Fv/Fm, and PIabs (p<0.05). This result further indicates the importance of P element for plant growth under the background of nitrogen deposition. ”.