Melatonin Treatment Delays the Senescence of Cut Flowers of “Diguan” Tree Peony by Affecting Water Balance and Physiological Properties

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

 

(1) line 25: please replace the hydrologic balance with water balance throughout the text

(2) line 24: which aspects of morphology were measured?

(3) lines 32-36: are these variables indicators (predictors) of vase life? This is a very strong statement. Are there any other literature data on this relation?

(4) line 62: what is catheter? Please correct it

(5) Cut flower wilting is a key limiting event, frequently terminating vase life (Ahmadi-Majd et al., 2023 J HORTIC SCI BIOTECH 98, 246–261). This symptom is elicited by adverse water relations, arising when the transpirational water loss exceeds vase solution uptake. In this perspective, down-regulating transpiration or up-regulating solution uptake is a direct modus of postponing wilting symptoms, and thus prolonging vase life. Incorporating melatonin in the holding solution favored the balance between water loss and uptake, as well as increased both cut flower fresh weight and the duration of increased fresh weight (Far et al. 2024 J HORTIC SCI BIOTECH 99, 597–608).

Upon exposure to unfavorable conditions, oxidative stress also induces vase life terminating symptoms (Ahmadi-Majd et al., 2023 J HORTIC SCI BIOTECH 98, 246–261). It is expressed through excessive generation of ROS, which in turn stimulate a range of undesirable effects, including lipid peroxidation, membrane damage and electrolyte leakage. On this basis, activating the ROS scavenging system is another approach of delaying terminating symptoms, and thus prolonging cut flower longevity. Incorporating melatonin in the holding solution alleviated the senescence symptoms (chlorophyll content decrease, as well as electrolyte leakage and MDA content increase). This alleviation coincided with the activation of both non-enzymatic (carotenoid content) and enzymatic (POD and CAT) defense (Far et al. 2024 J HORTIC SCI BIOTECH 99, 597–608).

(6) line 105: cultivation season, age of the plants, growth substrate, growth conditions (light, temperature, humidity), greenhouse of field cultivation?

(7) line 120: light intensity, quality and photoperiod during vase life evaluation. Please also mention relative air humidity during the same period

(8) Table 1: the effects of the control solution (containing sugar and biocide) as compared to deionized water are not treated in the text. Sugar (in the presence of biocide) promotes both flower opening and vase life.

(9) lines 91-93 & 323-327: Melatonin prolongs vase life in cut carnation flowers in both control and stress (simulated vibration) conditions (Far et al. 2024 J HORTIC SCI BIOTECH 99, 597–608).

(10) lines 329-332 & 345-359: Recent work also indicates that the application of melatonin n the holding solution has successfully prolonged cut carnation vase life by both improving water balance and boosting antioxidant activity (Far et al. 2024 J HORTIC SCI BIOTECH 99, 597–608). This natural and environmentally friendly sub[1]stance exhibited promising results, suggesting that it could serve as a viable alternative to harmful chemical compounds, posing risks to both environment and human health.

Comments on the Quality of English Language

english is OK

Author Response

Response to Reviewer 1 Comments

 

Dear Reviewer, thank you so much for your arduous labor. Your valuable suggestions have greatly helped us improve the quality of our article. We have made revisions based on your suggestions and hope to receive your approval.

 

Point 1: Introduction.The authors should emphasize the practical significance and potential applications of their findings in the cut flower industry to strengthen the conclusion of the introduction. Please correct.

Response 1: Thank you very much for your comments. We have corrected the following content in the introduction section.Applied to post-harvest treatments to extend the freshness period.The application of melatonin during the harvesting, transportation, and storage of cut flowers can effectively extend their freshness and shelf life. By incorporating melatonin into these critical stages, the natural aging process is slowed, ensuring that the flowers remain vibrant and durable for a longer period. This approach not only enhances the quality of the cut flowers but also supports more efficient logistics and storage solutions in the floral industry.

 

Point 2: Please, provide a brief description of the methods used for determining soluble protein content, peroxidase (POD) activity, superoxide dismutase (SOD) activity, and catalase (CAT) activity.

 

Response 2: Thank you very much for your comments.

 

Point 3: lines 32-36: are these variables indicators (predictors) of vase life? This is a very strong statement. Are there any other literature data on this relation?

 

Response 3: Thank you very much for your comments.

 

Point 4: line 62: what is catheter? Please correct it

 

Response 4: Thank you very much for your comments. We have modified it.

 

Point 5: Cut flower wilting is a key limiting event, frequently terminating vase life (Ahmadi-Majd et al., 2023 J HORTIC SCI BIOTECH 98, 246–261). This symptom is elicited by adverse water relations, arising when the transpirational water loss exceeds vase solution uptake. In this perspective, down-regulating transpiration or up-regulating solution uptake is a direct modus of postponing wilting symptoms, and thus prolonging vase life. Incorporating melatonin in the holding solution favored the balance between water loss and uptake, as well as increased both cut flower fresh weight and the duration of increased fresh weight (Far et al. 2024 J HORTIC SCI BIOTECH 99, 597–608).

Upon exposure to unfavorable conditions, oxidative stress also induces vase life terminating symptoms (Ahmadi-Majd et al., 2023 J HORTIC SCI BIOTECH 98, 246–261). It is expressed through excessive generation of ROS, which in turn stimulate a range of undesirable effects, including lipid peroxidation, membrane damage and electrolyte leakage. On this basis, activating the ROS scavenging system is another approach of delaying terminating symptoms, and thus prolonging cut flower longevity. Incorporating melatonin in the holding solution alleviated the senescence symptoms (chlorophyll content decrease, as well as electrolyte leakage and MDA content increase). This alleviation coincided with the activation of both non-enzymatic (carotenoid content) and enzymatic (POD and CAT) defense (Far et al. 2024 J HORTIC SCI BIOTECH 99, 597–608).

 

Response 5: Thank you very much for your suggestions and comments, which we have taken in the introduction.

 

Point 6: line 105: cultivation season, age of the plants, growth substrate, growth conditions (light, temperature, humidity), greenhouse of field cultivation?

 

Response 6: Thank you very much for your comments. We made supplements in the methods to clearly reflect the cultivation season of the materials, plant age, etc.

 

Point 7: line 120: light intensity, quality and photoperiod during vase life evaluation. Please also mention relative air humidity during the same period

 

Response 7: Thank you very much for your comments. We have elaborated on this content in the Materials and Methods section.

.

Point 8: Table 1: the effects of the control solution (containing sugar and biocide) as compared to deionized water are not treated in the text. Sugar (in the presence of biocide) promotes both flower opening and vase life.

Response 8:Thank you very much for your comments. We have supplemented all the observed lifetimes of the treatments in the results section, which can reflect the effect of the control solution.

 

Point 9:lines 91-93 & 323-327: Melatonin prolongs vase life in cut carnation flowers in both control and stress (simulated vibration) conditions (Far et al. 2024 J HORTIC SCI BIOTECH 99, 597–608).

Response 9: Thank you very much for your suggestions and comments, which we have taken in the introduction.

Point 10 : lines 329-332 & 345-359: Recent work also indicates that the application of melatonin n the holding solution has successfully prolonged cut carnation vase life by both improving water balance and boosting antioxidant activity (Far et al. 2024 J HORTIC SCI BIOTECH 99, 597–608). This natural and environmentally friendly sub[1]stance exhibited promising results, suggesting that it could serve as a viable alternative to harmful chemical compounds, posing risks to both environment and human health.

Response 10:Thank you very much for your suggestions and comments, which we have taken in the introduction.

 

 

 

 

 

 

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Editorial Board Members and Authors,

Thank you for the opportunity to review this manuscript titled “Effects of melatonin on the preservation of Paeonia suffruticosa ‘Diguan’ cut flowers.” The study examines the influence of different melatonin concentrations on the physiological and biochemical parameters of Paeonia suffruticosa ‘Diguan’ cut flowers, with an emphasis on extending vase life.

The manuscript is well-structured and addresses an important issue in the cut flower industry, particularly for Paeonia suffruticosa, a species of growing significance. The experimental design is appropriate, and the inclusion of antioxidant enzyme activities, and soluble protein content strengthens the study's contributions. The findings hold relevance for the cut flower industry, offering practical recommendations for preserving ornamental quality and extending vase life.

Specific comments and suggestions for revisions are provided below.

Introduction

1.      The authors should emphasize the practical significance and potential applications of their findings in the cut flower industry to strengthen the conclusion of the introduction. Please correct.

Material and methods

1.      Please, provide a brief description of the methods used for determining soluble protein content, peroxidase (POD) activity, superoxide dismutase (SOD) activity, and catalase (CAT) activity.

Results

1.      Consider moving the statement from lines 171–173 about the T3 treatment's impact on blooming period and ornamental value to the discussion section for a more comprehensive interpretation of the results.

2.      Please clarify why biochemical parameters were measured only for CK1 and T3 treatments, despite the study including multiple treatments. If these parameters were measured for all treatments, consider presenting the data either in the main text or as supplementary material to provide a comprehensive overview.

3.      The sentence in lines 311-312 is more appropriate for the discussion section.

Discussion

1.      Please consider expanding the discussion to further elaborate on the significance of these biochemical parameters (soluble protein, POD and SOD) in relation to the postharvest quality and longevity of cut flowers. A more detailed explanation of how these parameters reflect the physiological state of the flowers could provide deeper insights into the mechanisms influencing vase life.

 

Best wishes,

Author Response

Response to Reviewer 1 Comments

 

Dear Reviewer, thank you so much for your arduous labor. Your valuable suggestions have greatly helped us improve the quality of our article. We have made revisions based on your suggestions and hope to receive your approval.

 Point 1: Introduction.The authors should emphasize the practical significance and potential applications of their findings in the cut flower industry to strengthen the conclusion of the introduction. Please correct.

Response 1: Thank you very much for your comments. We have corrected the following content in the introduction section.Applied to post-harvest treatments to extend the freshness period.The application of melatonin during the harvesting, transportation, and storage of cut flowers can effectively extend their freshness and shelf life. By incorporating melatonin into these critical stages, the natural aging process is slowed, ensuring that the flowers remain vibrant and durable for a longer period. This approach not only enhances the quality of the cut flowers but also supports more efficient logistics and storage solutions in the floral industry.

 

Point 2: Please, provide a brief description of the methods used for determining soluble protein content, peroxidase (POD) activity, superoxide dismutase (SOD) activity, and catalase (CAT) activity.

 

Response 2: Thank you very much for your comments.We have supplemented the methods in the Materials and Methods section.

 

Point 3:  Consider moving the statement from lines 171–173 about the T3 treatment's impact on blooming period and ornamental value to the discussion section for a more comprehensive interpretation of the results.

Response 3: Thank you very much for your comments. We have modified it.

 

Point 4: Please clarify why biochemical parameters were measured only for CK1 and T3 treatments, despite the study including multiple treatments. If these parameters were measured for all treatments, consider presenting the data either in the main text or as supplementary material to provide a comprehensive overview.

 

Response 4: Thank you very much for your comments. During the preliminary research process, we comprehensively considered and analyzed multiple relevant indicators. We conducted a systematic evaluation of a series of indicators, such as relative flower diameter, fresh weight of flower branches and water balance value and so on.We found that among different treatment groups, the T3 group had the longest vase life, which was much higher than that of other treatments, and it also had the best performance in related indicators. Therefore, we determined that the T3 group was the optimal treatment method. Subsequently, we measured the physiological indicators of the CK1 and T3 groups.

 

Point 5: The sentence in lines 311-312 is more appropriate for the discussion section.

 

Response 5: Thank you very much for your suggestions and comments, we have modified it.

 

 

Point 6:  Please consider expanding the discussion to further elaborate on the significance of these biochemical parameters (soluble protein, POD and SOD) in relation to the postharvest quality and longevity of cut flowers. A more detailed explanation of how these parameters reflect the physiological state of the flowers could provide deeper insights into the mechanisms influencing vase life.

 

Response 6: Thank you very much for your suggestions and comments,we have taken your suggestions into account and broadened the scope of the discussion

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Editors and Authors,

 

I read with interest the manuscript entitled “Effects of melatonin on the preservation of Paeonia suffruticosa ‘Diguan’ cut flowers”. Therefore, this study used 'Diguan' tree peony to investigate the effects of exogenous melatonin at different concentrations on the post-harvest vase life and quality as well as the physiological and biochemical properties of tree peony cut flowers, with the aim of providing the theoretical basis for further analyzes of the aging mechanisms of tree peony cut flowers treated with melatonin during their vase life. The subject of the article is important and has great relevance for the scientific environment of the study area. Therefore, the manuscript needs some adjustments so that it can then be forwarded to the publication process. The manuscript has the potential for publication in this journal Horticulturae and needs the following adjustments:

 

TITLE

 

- Is the term “preservation” related to the variables analyzed in this study?

 

ABSTRACT

 

- Mention the scientific name of the species in the first line.

- In the objectives, it is not necessary to describe the melatonin concentrations. The objective should be described and in another sentence the treatments used (melatonin concentrations) can be inserted.

- The objective should be in accordance with what was mentioned in the last paragraph of the Introduction.

- Delete or replace keywords that are repeated in the title.

 

INTRODUCTION

 

- In the first paragraph, the name of the species “peony” was mentioned several times. Modify it and try not to repeat the same word several times within the same paragraph.

- In the second paragraph, paragraph this happened again (Lines 57-60).

- Lines 67-68: “Many studies have shown that treating cut flowers with antioxidants can effectively prolong the full flowering period.” Which studies? No references were cited. Insert references to these studies.

- The objective should be in accordance with what is presented in the Abstract.

- Insert hypotheses to enrich the paragraph. Insert them before the objectives.

 

MATERIAL AND METHODS

 

- Add the geographic coordinates of the study site.

- How old were the plants at the time the branches were collected? Add this information.

- How were these flowers grown? Was substrate used? How was the irrigation carried out? What management was adopted? ? This information should be described in the first paragraph.

- What was the experimental design used? How many replicates (or blocks) per treatment?

- Table 1 is not necessary. The treatments were described in the text. Add CK0 and CK1 in the text. This was not done.

- Rename subtopic 2.2 to “Analyzed variables”.

- Subtopic 2.2.1.: replace the term “examination”. What variables were analyzed here? This was not mentioned. Were they morphological or growth variables?

- How was it Did you quantify the diameter of the flower? Did you use any equipment? Graduated ruler? Digital images? Detail and add more information on how this analysis was done. - Is the flower diameter (subtopic 2.2.2.) the same variable as the relative flower diameter? Standardize, in some parts of the text it is referred to only as “flower diameter”. This variable was calculated according to which methodology? Cite study.

- Provide more details on the analyzes of topics 2.2.3., 2.2.4 and 2.2.5.

- Was any test of homogeneity and normality of the data performed? And was the analysis of variance not performed?

 

RESULTS

 

- The subtitles should be rewritten. It is too broad, similar to an article title.

- Any result described should be accompanied by a Table or Figure citation in the sentence. In several passages throughout the results this was not done.

- Visually it was possible to observe the effect of the treatments, as shown in Figure 1. To state that there was an effect, it is necessary to present the data, and then the figure. With just the figure we cannot state for sure that there was this effect. Organize information and combine results from the figure with collected data.

- The Y-axis title in Figure 4 has letters cut off. Correct.

- Reduce the font size of figures 5, 6, 7 and 8.

 

DISCUSSION

 

- This section needs to be increased.

- Some information is not Discussion, but rather a literature review.

- This section should be completely revised.

 

CONCLUSION

 

- Remove “In summary”.

Author Response

Response to Reviewer 1 Comments

 

Dear Reviewer, thank you so much for your arduous labor. Your valuable suggestions have greatly helped us improve the quality of our article. We have made revisions based on your suggestions and hope to receive your approval.

 

 Point 1: TITLE- Is the term “preservation” related to the variables analyzed in this study?

 

Response 1: Thank you very much for your comments. We've changed the title to:Melatonin treatment delays the senescence of cut flowers of ‘Dguan’Peony by affecting water balance and physiological properties

 

Point 2: ABSTRACT- Mention the scientific name of the species in the first line.In the objectives, it is not necessary to describe the melatonin concentrations. The objective should be described and in another sentence the treatments used (melatonin concentrations) can be inserted.

 

Response 2: Thank you very much for your comments.We have modified it.

 

Point 3:   - The objective should be in accordance with what was mentioned in the last paragraph of the Introduction.- Delete or replace keywords that are repeated in the title.

 

Response 3: Thank you very much for your comments. We have modified it.

 

Point 4: INTRODUCTION- In the first paragraph, the name of the species “peony” was mentioned several times. Modify it and try not to repeat the same word several times within the same paragraph.- In the second paragraph, paragraph this happened again (Lines 57-60).

 

Response 4: Thank you very much for your comments. We have modified it.

 

Point 5: - Lines 67-68: “Many studies have shown that treating cut flowers with antioxidants can effectively prolong the full flowering period.” Which studies? No references were cited. Insert references to these studies.

 

Response 5: Thank you very much for your suggestions and comments, we have cited references about antioxidant treatment of cut flowers can be effective in prolonging flowering.

 

 

Point 6: - The objective should be in accordance with what is presented in the Abstract.

- Insert hypotheses to enrich the paragraph. Insert them before the objectives.

 

Response 6: Thank you very much for your suggestions and comments, we have modified it.

 

Point 7: MATERIAL AND METHODS- Add the geographic coordinates of the study site.- How old were the plants at the time the branches were collected? Add this information.

 

Response 7:Thank you very much for your suggestions and comments,we have already added it in the Materials and Methods section

 

Point 8: - How were these flowers grown? Was substrate used? How was the irrigation carried out? What management was adopted? ? This information should be described in the first paragraph.

 

Response 8: Thank you very much for your comments.We have already added it in the Materials and Methods section.

 

 

Point 9: - What was the experimental design used? How many replicates (or blocks) per treatment?

 

Response 9: Thank you very much for your comments. Each treatment involved three flowering branches and was replicated six times for a total of eighteen flowering branches per group.

 

Point 10: - Table 1 is not necessary. The treatments were described in the text. Add CK0 and CK1 in the text. This was not done.- Rename subtopic 2.2 to “Analyzed variables”.

 

Response 10: Thank you very much for your comments.We have considered deleting Table 1 to supplement the viewing life to make the data more intuitive. We have modified it.

 

Point 11: - Subtopic 2.2.1.: replace the term “examination”. What variables were analyzed here? This was not mentioned. Were they morphological or growth variables?

 

Response 11: Thank you very much for your suggestions and comments.We observed the morphological variables.During the vase period, three cut flowers per treatment group were randomly selected daily at 9 am. They were photographed and their morphological characteristics were examined. Observe whether the petals maintain an upright stance, exhibit increased brittleness, or become thinner. Inspect whether the stem incisions show signs of blackening or decay, and whether the leaves retain their green color or undergo yellowing or browning. Additionally, measure the vase life as a comprehensive morphological parameter.

 

Point 12: - How was it Did you quantify the diameter of the flower? Did you use any equipment? Graduated ruler? Digital images? Detail and add more information on how this analysis was done. - Is the flower diameter (subtopic 2.2.2.) the same variable as the relative flower diameter? Standardize, in some parts of the text it is referred to only as “flower diameter”. This variable was calculated according to which methodology? Cite study.

 

Response 12: Thank you very much for your comments. Each day at a consistent time, the maximum flower diameter of three randomly selected peony cut flowers was measured using digital vernier caliper with a precision of 0.01 mm.The data should include fields such as sample number, treatment/control group, measurement time, and flower diameter. Avoid touching the petals to minimize mechanical damage.. This procedure was repeated three times, and the average value was calculated.Calculate according to the following formula.D1 and D2 are the flower diameters at times t1 and t2, respectively

 

Point 13:- Provide more details on the analyzes of topics 2.2.3., 2.2.4 and 2.2.5.

- Was any test of homogeneity and normality of the data performed? And was the analysis of variance not performed?

 

Response 13: Thank you very much for your comments. We have already added it in the Materials and Methods section. The data were processed and analyzed using SPSS 22.0 software and Microsoft Office 2016. To assess the differences between treatment groups, a one-way ANOVA was conducted. Subsequently, Duncan's method was utilized for multiple comparisons, with a significance level set at P < 0.05. To ensure the reliability of the results, all data were subjected to three repetitions, and the mean standard error (SE) was calculated.

.

Point 14:RESULTS- The subtitles should be rewritten. It is too broad, similar to an article title.

 

Response 14:Thank you very much for your comments. We have modified it.

 

Point 15:Any result described should be accompanied by a Table or Figure citation in the sentence. In several passages throughout the results this was not done.

Response 15: Thank you very much for your comments. We have modified it.

 

 Point16: - Visually it was possible to observe the effect of the treatments, as shown in Figure 1. To state that there was an effect, it is necessary to present the data, and then the figure. With just the figure we cannot state for sure that there was this effect. Organize information and combine results from the figure with collected data.

 

Response 16: Thank you very much for your comments. Thank you very much for your comments. We have supplemented this content and added a vase lifespan chart to make the data more intuitive.

Point 17 :The Y-axis title in Figure 4 has letters cut off. Correct.- Reduce the font size of figures 5, 6, 7 and 8.

 

Response 17:Thank you very much for your suggestions and comments.We have corrected it.

 

 

 Point18: DISCUSSION- This section needs to be increased.- Some information is not Discussion, but rather a literature review.- This section should be completely revised.

 

Response 18: Thank you very much for your comments. We have made changes based on your feedback.

 

Point 19: CONCLUSION- Remove “In summary”.

 

Response 19: Thank you very much for your comments.We have modified it.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

authors followed my previous suggestions, and the manuscript has been clearly improved

line 53: peony cut flowers (not cuttings)

line 64: introduce here the abbreviation ROS (and not later on in line 395)

line 121: since it is a field cultivation, the term veltilation is not appropriate

line 153: I would not rank vase life as a morphological parameter, please adjust

throughout the manuscript: by "relative cut flower trail" do you mean "relative flower opening/ diameter", please adjust 

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Corrections have been made.

Author Response

Please see the attachment

Author Response File: Author Response.pdf