Singlet Oxygen Generation and Signaling in Higher Plants

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Singlet oxygen is a fundamental reactive oxygen species. It is not only a cytotoxin, but also a signal involved in plant growth, development and stress responses. This review systematically summarizes current research on ¹O₂ generation, perception, signaling in plant cells and discuss the role of ¹O₂ in plant environmental responses, particularly the cross talk between ¹O₂ and the signaling pathways of phytohormones JA and SA. This review is well-organized, comprehensive, and effectively integrates the latest relevant research findings, making it an outstanding review paper. 

Here are some areas that could be improved.

1、Since the generation of singlet oxygen is a major focus of the review, I think it’s better to add a figure or a table to visually summarize this section.

2、Figure 1: For better clarity and alignment with the text, I think Fig. 1 should be revised to show the grana core and grana margin separately, along with their distinct singlet oxygen signaling pathways.

3、The article is written in fluent language, but there are some grammatical errors that may have resulted from oversight, requiring the author to conduct a thorough review and make corrections, e.g.:

（1）In Abstract, Line 17: ‘1O2 also act as a signal...’. "act" should be changed to "acts".

（2）In Introduction, Line 39: ‘as more the80% of photooxidative damages....’ Here the "the" should be changed to "than".

(3) Line 242: ‘Based on the sites of ¹O₂ generation, ¹O₂ induced signaling in the chloroplast can originated from grana core...’. "originated" should be changed to "originate".

(4) Line 252: ‘but had no obvious effect on the expression H2O2-responsive genes.’  "expression" should be changed to "expression of".

(5) Line 252: ‘Thus, β-CC are considered as a second messenger’. "are" should be changed to "is".

（6）Line 471: ‘... the resulting flu opr3is largely suppressed,’ "is" should be changed to "was".

4、Line 307: ‘ However, this study is questioned by another study published this year which shown that mature EX1 protein does not accumulate in the nucleus, and does not interact with nuclear WRKY18 or WRKY40, either. ’ Here, please replace ‘this year’ with the exact year, and the corresponding reference must be cited.

 

 

Author Response

Response to Reviewer #1

Singlet oxygen is a fundamental reactive oxygen species. It is not only a cytotoxin, but also a signal involved in plant growth, development and stress responses. This review systematically summarizes current research on ¹O₂ generation, perception, signaling in plant cells and discuss the role of ¹O₂ in plant environmental responses, particularly the cross talk between ¹O₂ and the signaling pathways of phytohormones JA and SA. This review is well-organized, comprehensive, and effectively integrates the latest relevant research findings, making it an outstanding review paper.

Response: We deeply appreciate your positive comments and we hope this manuscript will be of great interest to readers.

Here are some areas that could be improved.

1. Since the generation of singlet oxygen is a major focus of the review, I think it’s better to add a figure or a table to visually summarize this section.

Response: This a very good idea, thanks a lot. According to your suggestion, we summarized the source of singlet oxygen, the underlying mechanism and related mutants in Table 1. This table is very friendly to readers since it is concise but informative.

 

2. Figure 1: For better clarity and alignment with the text, I think Fig. 1 should be revised to show the grana core and grana margin separately, along with their distinct singlet oxygen signaling pathways.

Response: Thanks for your constructive suggestions. Following your suggestion, we modified Fig.1 (Fig.2 in the revised version) based on the site of singlet oxygen generation origin of singlet oxygen-induced signaling, i.e., grana core and grana margin. Now, this figure looks much better than the previous one.

 

3. The article is written in fluent language, but there are some grammatical errors that may have resulted from oversight, requiring the author to conduct a thorough review and make corrections, e.g.:

(1) In Abstract, Line 17: ‘1O2 also act as a signal...’. "act" should be changed to "acts".

(2) In Introduction, Line 39: ‘as more the80% of photooxidative damages....’ Here the "the" should be changed to "than".

(3) Line 242: ‘Based on the sites of ¹O₂ generation, ¹O₂ induced signaling in the chloroplast can originated from grana core...’. "originated" should be changed to "originate".

(4) Line 252: ‘but had no obvious effect on the expression H₂O₂-responsive genes.’ "expression" should be changed to "expression of".

(5) Line 252: ‘Thus, β-CC are considered as a second messenger’. "are" should be changed to "is".

(6) Line 471: ‘... the resulting flu opr3is largely suppressed,’ "is" should be changed to "was".

Response: Thanks for your comments. We have addressed all the points and revised the manuscript accordingly. Meanwhile, we scrutinized this manuscript thoroughly, not only for checking grammatical errors, but also for improving its overall quality. All these changes are marked by brilliant yellow background, and are easily to follow.

4. Line 307: ‘However, this study is questioned by another study published this year which shown that mature EX1 protein does not accumulate in the nucleus, and does not interact with nuclear WRKY18 or WRKY40, either.’ Here, please replace ‘this year’ with the exact year, and the corresponding reference must be cited.

Response: Thanks for your suggestion. The article titled “EXECUTER1 and singlet oxygen signaling: A reassessment of nuclear activity” was published in 2024, and we have changed the year to 2024 and cited it according to your suggestion.

Reviewer 2 Report

Comments and Suggestions for Authors

The type of article dealing with singlet oxygen formation and functions in plants. Singlet oxygen is a type of so-called reactive oxygen species that play an important role in the redox cellular signal cascade. Therefore, the topic of this manuscript is interesting and interesting for the scientific field.

The authors summarized the current set of information about the role of ROS, especially singlet oxygen in tissues and cells. The structure of the paper is logic. The presented figures are illustrative. Additionally, the authors included all relevant aspects of the pathological and molecular biological aspects of the singlet oxygen in the plant organism. The cited references are relevant.

Author Response

Response to Reviewer #2

The type of article dealing with singlet oxygen formation and functions in plants. Singlet oxygen is a type of so-called reactive oxygen species that play an important role in the redox cellular signal cascade. Therefore, the topic of this manuscript is interesting and interesting for the scientific field. The authors summarized the current set of information about the role of ROS, especially singlet oxygen in tissues and cells. The structure of the paper is logic. The presented figures are illustrative. Additionally, the authors included all relevant aspects of the pathological and molecular biological aspects of the singlet oxygen in the plant organism. The cited references are relevant.

Response: Thank you for reviewing our manuscript and for your very positive assessment of our work. Your encouraging feedback is greatly appreciated.

Reviewer 3 Report

Comments and Suggestions for Authors

1-The aims must be clear

2- Must add abbreviations 

3- In part 2.2. Please make a diagram

4. In part, about abiotic stress, please divide into parts according to the stress and make a difference in response in the table.

Author Response

Response to Reviewer #3

1. The aims must be clear.

Response: Thanks for your suggestion. Our review aims to systematically summary the production and signal transduction pathways of ¹O₂ in plants, clarify the independence and interactions of ¹O₂ signaling with phytohormones, and summarize the ¹O₂-induced chloroplastic and photosynthetic changes under various stress conditions. We have added the aims in the Abstract section.

2. Must add abbreviations

Response: Thanks for your comments. According to your suggestion, we add a new section named “Abbreviations” after the “Conclusion remarks” section.

3. In part 2.2. Please make a diagram

Response: According to your suggestion, we have visually mapped the main intermediates of chlorophyll synthesis and metabolism that can generate singlet oxygen as shown in Figure 2 and Table 1.

4. In part, about abiotic stress, please divide into parts according to the stress and make a difference in response in the table.

Response: Thanks for your good suggestion. According to your suggestion, we divide abiotic stress into four parts and make a difference in response as shown in Table 2.

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

We accept in present form