Particulate Matter (PM) Adsorption and Leaf Characteristics of Ornamental Sweet Potato (Ipomoea batatas L.) Cultivars and Two Common Indoor Plants (Hedera helix L. and Epipremnum aureum Lindl. & Andre)
, Hualin Nie 3 and Sun Hyung Kim 1,*Round 1
Reviewer 1 Report
The problem that the authors decided to solve is important environmental problem, especially in the light of climate change and increasing pollution of air and water resources.
Title – I suggest rewriting the tittle of the manuscript.
The introduction clearly presents the problem and goals the authors want to achieve with the paper. The goal stated by the author is of big importance.
Lines 45 – 48 – unclear, suggest rewriting
Material and methods
109 – the term ‘seedling’ rather refers to a plant developed from a seed (‘plantlet’).
The description of the results may be accepted. The discussion explains the meaning of the results exhaustively. It contains reference to many items of the worldwide literature.
Line 230 please verify the description with Table 1 (“…more stomata…”)
Keywords should not repeat words or phrases that appear in the title but instead they should supplement them.
Author Response
Title
Particulate matter (PM) adsorption and leaf characteristics of ornamental sweet potato (Ipomoea batatas L.) cultivars: PM mitigation by plants
We are pleased to resubmit for publication the revised version of entitled “Particulate matter (PM) adsorption and leaf characteristics of ornamental sweet potato (Ipomoea batatas L.) cultivars: PM mitigation by plants”. We would like to thank the reviewers and the associate editor for their precious time and invaluable comments. We are very much thankful to three reviewers for deep and thorough comments on an amended version of the manuscript. We have revised our manuscript according to their suggestions and comments of three anonymous reviewers. We have carefully addressed each of comments by three reviewers as outlined below. We hope that the reviewers and the editors will be satisfied with author's reply to the review report and the revised version.
Yours sincerely,
Comments and Suggestions for Authors
The problem that the authors decided to solve is important environmental problem, especially in the light of climate change and increasing pollution of air and water resources.
Title – I suggest rewriting the tittle of the manuscript.
Reply: We are grateful for your precise and detailed comments. We have rewritten the title to shorten and clarify this research.
Line 2-4: Particulate matter (PM) adsorption and leaf characteristics of ornamental sweet potato (Ipomoea batatas L.) cultivars: PM mitigation by plants
The introduction clearly presents the problem and goals the authors want to achieve with the paper. The goal stated by the author is of big importance.
Lines 45 – 48 – unclear, suggest rewriting
Reply: Based on the comment of reviewer, we have revised the sentence in ‘Introduction’ section to make it clear.
Line 46-50: Since PM from the outside might enter the building via natural ventilation including doors and windows, indoor PM concentrations have risen as a result of the transfer of increasing large amounts of outdoor-generated particles to indoor environments and the emission of indoor-originated particles [5]. In many cases, indoor PM concentrations strongly coincide with the trends of PM concentration trends in urban areas [6,7].
Material and methods
109 – the term ‘seedling’ rather refers to a plant developed from a seed (‘plantlet’).
Reply: According to your suggestion, we have changed the term in ‘Materials and Methods’ section.
Line 112-115: The plantlets were placed in a greenhouse at the University of Seoul, Seoul, Korea (37°3457.5′ N, 127°0339.1′ E) for a month after being transplanted into 1 L plastic pots containing a commercial substrate (Green partner, Nongwoo Bio, Suwon, Korea).
The description of the results may be accepted. The discussion explains the meaning of the results exhaustively. It contains reference to many items of the worldwide literature.
Line 230 please verify the description with Table 1 (“…more stomata…”)
Reply: Thank you for pointing this out. We have revised the sentence in ‘Morphological and stomatal characteristics’ section.
Line 244-247: Although their leaves were amphistomatous, stomatal densities on the abaxial surfaces were significantly higher (Table 1), except for B leaves, which had no significant between their both surfaces.
Keywords should not repeat words or phrases that appear in the title but instead they should supplement them.
Reply: Thank you for pointing this out. We have changed some keywords.
Keywords: Ipomea batatas L.; Ornamental plant; Morphological characteristics; Particulate matter; Physiological characteristics; PM mitigation
Author Response File: 
Author Response.docx
Reviewer 2 Report
The review concerned an article entitled: Particulate matter (PM) adsorption and leaf characteristics of ornamental sweet potato (Ipomoea batatas L.) cultivars were investigated to understand PM mitigation by plants. Air pollution is still an important topic, especially in places with high pollution where phytoremediation as a solution could be used. Mitigation of indoor air pollution is more and more important this days. Due to the fact that my native language is not English, I will not check the linguistic correctness of the manuscript. Overall the article is interesting and although it touches on an repeated topic it provides a refreshing approach to research on the indoor phytoremediation.
Just a few questions:
Questions/mistakes/errors,
Line – 1-4. The title is too long. It’s not like a title but like description of the research.
Line 16. Please check English spelling – plants can function as biofilters.
Line 20. There is no authors name on Epiprenum.
Line 118 – Do the empty chamber was check on the accumulation.
Line 133 – Do authors have checked how many particles stacked to the chamber walls. It was significant?
Line 158 – The leaf surface of the leaves – is not English correct and sound weird.
Line 159 – Do The authors had an ability to measure different fractions of PM. Do authors think that can be significant ?
Line 314 – Do authors measured how the PM can block stomata. If not the citation is needed.
Line 315 – Do authors measured absorption of the light by leaves – if not citation is also needed here.
Line 333 – The full name of Scidamptus is also needed.
Author Response
Author's Reply to the Review Report
(Manuscript ID: horticulturae-1512812)
Title
Particulate matter (PM) adsorption and leaf characteristics of ornamental sweet potato (Ipomoea batatas L.) cultivars: PM mitigation by plants
We are pleased to resubmit for publication the revised version of entitled “Particulate matter (PM) adsorption and leaf characteristics of ornamental sweet potato (Ipomoea batatas L.) cultivars: PM mitigation by plants”. We would like to thank the reviewers and the associate editor for their precious time and invaluable comments. We are very much thankful to three reviewers for deep and thorough comments on an amended version of the manuscript. We have revised our manuscript according to their suggestions and comments of three anonymous reviewers. We have carefully addressed each of comments by three reviewers as outlined below. We hope that the reviewers and the editors will be satisfied with author's reply to the review report and the revised version.
Yours sincerely,
Comments and Suggestions for Authors
The review concerned an article entitled: Particulate matter (PM) adsorption and leaf characteristics of ornamental sweet potato (Ipomoea batatas L.) cultivars were investigated to understand PM mitigation by plants. Air pollution is still an important topic, especially in places with high pollution where phytoremediation as a solution could be used. Mitigation of indoor air pollution is more and more important this days. Due to the fact that my native language is not English, I will not check the linguistic correctness of the manuscript. Overall the article is interesting and although it touches on an repeated topic it provides a refreshing approach to research on the indoor phytoremediation.
Just a few questions:
Questions/mistakes/errors,
Line – 1-4. The title is too long. It’s not like a title but like description of the research.
Reply: We are grateful for your precise and detailed comments. We have rewritten the title to shorten and clarify this research.
Line 2-4: Particulate matter (PM) adsorption and leaf characteristics of ornamental sweet potato (Ipomoea batatas L.) cultivars: PM mitigation by plants
Line 16. Please check English spelling – plants can function as biofilters.
Reply: Thank you for pointing this out. We have rephrased the sentence in ‘Abstract’ section.
Line 16: Plants can help to reduce PM pollution by acting as biofilters.
Line 20. There is no authors name on Epiprenum.
Reply: Thank you for bringing this to our attention. Epipremnum aureum Lindl. & Andre has been added as an author name to Epipremnum aureum.
Line 118 – Do the empty chamber was check on the accumulation?
Reply: According to your suggestion, we have added the sentence in ‘Plant materials and the PM fumigation chamber’ section to clarify the empty chamber was checked before the experiment began.
Line 127-129: Furthermore, before the experiments, the dust condition of chamber interior surface was carefully cleaned by wet and dry mopping.
Line 133 – Do authors have checked how many particles stacked to the chamber walls. It was significant?
Reply: Thank you for pointing this out. In the solid particle generator system, the airborne PM concentration was measured and regulated by a PM detector in real time to maintain target concentration, 300 μg m-3. Also, the test plants were placed in such a way that they would not be unaffected by dust on the chamber’s walls.
Line 130-132: Ten plants of each cultivar and species with similar growth conditions were placed in a chamber with a PM fumigator and also arranged in such a way that they would not be unaffected by particles on the chamber’s walls.
Line 158 – The leaf surface of the leaves – is not English correct and sound weird.
Reply: We are grateful for your precise and detailed comments. We have rewritten the sentence in ‘Measurement of PM adsorption on the leaf surfaces’ section.
Line 167-168: The surfaces of the leaves from each cultivar and species were randomly sampled.
Line 159 – Do The authors had an ability to measure different fractions of PM? Do authors think that can be significant ?
Reply: We are grateful for your precise, detailed comments and suggestions. We understand what you want to ask. The modified method adopted from Liu et al. (2018) and Kwak et al. (2019) in our research did not distinguish different fractions of PM because the main aim of this study was to determine which leaf characteristics influence the capacity of plants to adsorb PM. And measurement of different fraction of PM adsorption on leaves surface may make it unclear to the influence of leaf characteristics on PM adsorption. Since we also used fly ash test powder, which is typically under 10 μm in diameter, PM adsorption of test plants could be investigated well.
We have added this sentence in ‘Plant materials and the PM fumigation chamber’ section.
Line 123-124: Fly ash test powder (JIS test powder class 5, APPIE, Kyoto, Japan), which is typically under 10 μm in diameter, was used in this experiment.
Line 314 – Do authors measured how the PM can block stomata? If not the citation is needed.
Reply: According to your precise suggestions, we have added the citation in ‘Discussion’ section.
Line 328-330: There can be several reasons why an increase in the amount of retained PM leads to a reduction in the effective photosynthesis of plants. First, PM hinders gas exchange ability by blocking the stomata [45].
Line 315 – Do authors measured absorption of the light by leaves? – if not citation is also needed here.
Reply: According to your precise suggestions, we have added the citation in ‘Discussion’ section.
Line 330-331: Second, PM that has accumulated on the leaves covers the surface and thus prevents the leaves from absorbing light [46].
Line 333 – The full name of Scindapsus is also needed.
Reply: According to your suggestions, we have added the full name of scindapsus in ‘Discussion’ section.
Line 345-348: Ryu et al. [54] reported that the PM removal efficiencies of E. aureum are higher under light conditions than under dark conditions because light stimulates the opening of stomata, which leads to a higher transpiration rate.
Author Response File: Author Response.docx
Reviewer 3 Report
In this study, the authors investigated the PM adsorption and leaf characteristics of five ornamental sweet potato cultivars and two common indoor plants exposed to fly ash particles to assess the factors influencing PM adsorption on leaves and to understand the effects of PM pollution on the leaf characteristics of plants. This result provides a good insight into the PM retention of plant leaves. However, there are some serious problems which must be clarified in detail so that the result and conclusion can be persuading.
- Many articles have shown that leaf characteristics have obvious effects on particulate matter retention, including leaf area, stomata, etc.What are the results of this paper different from previous studies?
- The purpose of the article is to detect the retention performance of indoor plants to indoor particulate matters.But is the fly ash particles used only present indoors? What is the difference between indoor particulate matter and outdoor particles?
- The leaves were only cleaned by soaking method. The effect of soaking on cleaning leaves is similar to the effect of rainfall. That is to say, the PM on leaf surface perhaps cannot be cleaned completely using this method, and this will also vary in different species (some papers have talked about this). So, if this is true for the case in this study, there may be some deviations of the analysis result. How does the author consider about this problem. Please justify it.
- What is the precision of the used balance? The weight of the PM is very small. So, is the precision of the balance high enough to accurately measure PM weight?
- Does the data conform to the assumption of ANOVA, such as normality and homogeneity of variance? This should be clarified.
Author Response
Author's Reply to the Review Report
(Manuscript ID: horticulturae-1512812)
Title
Particulate matter (PM) adsorption and leaf characteristics of ornamental sweet potato (Ipomoea batatas L.) cultivars: PM mitigation by plants
We are pleased to resubmit for publication the revised version of entitled “Particulate matter (PM) adsorption and leaf characteristics of ornamental sweet potato (Ipomoea batatas L.) cultivars: PM mitigation by plants”. We would like to thank the reviewers and the associate editor for their precious time and invaluable comments. We are very much thankful to three reviewers for deep and thorough comments on an amended version of the manuscript. We have revised our manuscript according to their suggestions and comments of three anonymous reviewers. We have carefully addressed each of comments by three reviewers as outlined below. We hope that the reviewers and the editors will be satisfied with author's reply to the review report and the revised version.
Yours sincerely,
Comments and Suggestions for Authors
In this study, the authors investigated the PM adsorption and leaf characteristics of five ornamental sweet potato cultivars and two common indoor plants exposed to fly ash particles to assess the factors influencing PM adsorption on leaves and to understand the effects of PM pollution on the leaf characteristics of plants. This result provides a good insight into the PM retention of plant leaves. However, there are some serious problems which must be clarified in detail so that the result and conclusion can be persuading.
1. Many articles have shown that leaf characteristics have obvious effects on particulate matter retention, including leaf area, stomata, etc. What are the results of this paper different from previous studies?
Reply: We are grateful for pointing this out. As you mentioned, there were many studies reporting the influence of leaf characteristics on PM retention. Unlike they have usually focused on morphological characteristics only, scientific important of our research was to assess the influence of leaf gas exchange characteristics on PM adsorption. In addition, several research have been conducted in fields including parks. However, our research was conducted in growth chamber equipped with a PM generator system.
2. The purpose of the article is to detect the retention performance of indoor plants to indoor particulate matters. But is the fly ash particles used only present indoors? What is the difference between indoor particulate matter and outdoor particles?
Reply: Thank you for bringing this to our attention. As we mentioned in Introduction, Indoor-generated PM is caused by building materials, such as flooring, paint, and plastics, and human activities, including cooking and cleaning. Furthermore, since PM from the outside might enter the building via natural ventilation including doors and windows, the components of indoor particles are determined by the particles generated in both indoor and outside environments. So, fly ash, which is a source of anthropogenic particulate matter (PM) be occurred by both indoor (cooking and heating) and outdoor conditions (fossil fuel combustion).
we have revised and added sentences in ‘Introduction’ and ‘Plant materials and the PM fumigation chamber’ to clarify why we used fly ash for this research.
Line 46-49: Since PM from the outside might enter the building via natural ventilation including doors and windows, indoor PM concentrations have risen as a result of the transfer of increasing large amounts of outdoor-generated particles to indoor environments and the emission of indoor-originated particles [5].
Line 55-56: The components of indoor particles are determined by the particles generated in both indoor and outside environments [9].
Line 120-123: Fly ash, which is a source of anthropogenic particulate matter (PM) occurred by both indoor and outdoor conditions [39], was generated using a solid particle generator to simulate PM pollution conditions in plants.
3. The leaves were only cleaned by soaking method. The effect of soaking on cleaning leaves is similar to the effect of rainfall. That is to say, the PM on leaf surface perhaps cannot be cleaned completely using this method, and this will also vary in different species (some papers have talked about this). So, if this is true for the case in this study, there may be some deviations of the analysis result. How does the author consider about this problem? Please justify it.
Reply: Thank you for your precise and detailed comments. We totally agree with your opinion about soaking method. The measurement of PM adsorption on leaves using the soaking method can vary between species. However, the modified method adopted from Liu et al. (2018) and Kwak et al. (2019) in our research added ultrasonic cleaning to the soaking method. Ultrasonic cleaning is critical to assess the PM adsorption capacity of plants accurately and quantitatively.
We have added this sentence to justify our method.
Line 182-184: In this methods, ultrasonic cleaning is critical to assess the PM adsorption capacity of plants accurately and quantitatively [42].
4. What is the precision of the used balance? The weight of the PM is very small. So, is the precision of the balance high enough to accurately measure PM weight?
Reply: We are grateful for your precise comments. We have measured the mass of particulates per leaf area weighed with a high precision balance with an accuracy of 0.0001 g (PX124, Ohaus, Parsipanny, NJ, USA). It was high enough to accurately measure total PM weight on several leaves per species.
We have added this sentence to justify our method.
Line 181-183: The total mass of particles on leaves were determined using a high precision balance with an accuracy of 0.0001 g (PX124, Ohaus, Parsipanny, NJ, USA). It was high enough to accurately measure total PM weight on several leaves per species.
5. Does the data conform to the assumption of ANOVA, such as normality and homogeneity of variance? This should be clarified.
Reply: According to your precise suggestions, we have added this sentence in ‘Statistical analysis’ section.
Line 190-192: Both the Shapiro-Wilk normality test and the Barlett test of homogeneity of variance were used to check the assumptions of normality and homogeneity of variance.
Round 2
Reviewer 1 Report
Line 247. The sentence should be corrected ("...which had no significant...")
Keywords should not repeat words or phrases that appear in the title ('Particulate matter', 'PM mitigation')
All other issues have been corrected by the authors.
Author Response
Author's Reply to the Review Report
(Manuscript ID: horticulturae-1512812)
Title
Particulate matter (PM) adsorption and leaf characteristics of ornamental sweet potato (Ipomoea batatas L.) cultivars and two common indoor plants (Hedera helix L. and Epipremnum aureum Lindl. & Andre)
We are pleased to resubmit for publication the revised version of entitled “Particulate matter (PM) adsorption and leaf characteristics of ornamental sweet potato (Ipomoea batatas L.) cultivars and two common indoor plants (Hedera helix L. and Epipremnum aureum Lindl. & Andre)”. We would like to thank the reviewers and the associate editor for their precious time and invaluable comments. We are very much thankful to three reviewers for deep and thorough comments on an amended version of the manuscript. We have revised our manuscript according to their suggestions and comments of three anonymous reviewers. We have carefully addressed each of comments by three reviewers as outlined below. We hope that the reviewers and the editors will be satisfied with author's reply to the review report and the revised version.
Yours sincerely,
Review Report - Reviewer 1
Comments and Suggestions for Authors
Line 247. The sentence should be corrected ("...which had no significant...")
Reply: We are grateful for your precise and detailed comments. We have rewritten the sentence in ‘Morphological and stomatal characteristics’ section.
Line 245-247: Although their leaves were amphistomatous, stomatal densities on the abaxial surfaces were significantly higher, with the exception of B leaves (Table 1).
Keywords should not repeat words or phrases that appear in the title ('Particulate matter', 'PM mitigation')
Reply: We are grateful for your precise and detailed comments. We have rewritten the title to shorten and clarify this research.
Line 2-4: Particulate matter (PM) adsorption and leaf characteristics of ornamental sweet potato (Ipomoea batatas L.) cultivars and two common indoor plants (Hedera helix L. and Epipremnum aureum Lindl. & Andre)
All other issues have been corrected by the authors.
Author Response File: Author Response.docx
Reviewer 2 Report
I agree with corrections and answers. Article is ready to publish.
Author Response
Author's Reply to the Review Report
(Manuscript ID: horticulturae-1512812)
Title
Particulate matter (PM) adsorption and leaf characteristics of ornamental sweet potato (Ipomoea batatas L.) cultivars and two common indoor plants (Hedera helix L. and Epipremnum aureum Lindl. & Andre)
We are pleased to resubmit for publication the revised version of entitled “Particulate matter (PM) adsorption and leaf characteristics of ornamental sweet potato (Ipomoea batatas L.) cultivars and two common indoor plants (Hedera helix L. and Epipremnum aureum Lindl. & Andre)”. We would like to thank the reviewers and the associate editor for their precious time and invaluable comments. We are very much thankful to three reviewers for deep and thorough comments on an amended version of the manuscript. We have revised our manuscript according to their suggestions and comments of three anonymous reviewers. We have carefully addressed each of comments by three reviewers as outlined below. We hope that the reviewers and the editors will be satisfied with author's reply to the review report and the revised version.
Yours sincerely,
Review Report - Reviewer 2
Comments and Suggestions for Authors
I agree with corrections and answers. Article is ready to publish.
Reply: We would like to thank the reviewers for their precious time and invaluable comments.
Author Response File: Author Response.docx
Reviewer 3 Report
It can be accepted in present form.
Author Response
Author's Reply to the Review Report
(Manuscript ID: horticulturae-1512812)
Title
Particulate matter (PM) adsorption and leaf characteristics of ornamental sweet potato (Ipomoea batatas L.) cultivars and two common indoor plants (Hedera helix L. and Epipremnum aureum Lindl. & Andre)
We are pleased to resubmit for publication the revised version of entitled “Particulate matter (PM) adsorption and leaf characteristics of ornamental sweet potato (Ipomoea batatas L.) cultivars and two common indoor plants (Hedera helix L. and Epipremnum aureum Lindl. & Andre)”. We would like to thank the reviewers and the associate editor for their precious time and invaluable comments. We are very much thankful to three reviewers for deep and thorough comments on an amended version of the manuscript. We have revised our manuscript according to their suggestions and comments of three anonymous reviewers. We have carefully addressed each of comments by three reviewers as outlined below. We hope that the reviewers and the editors will be satisfied with author's reply to the review report and the revised version.
Yours sincerely,
Review Report - Reviewer 3
Comments and Suggestions for Authors
It can be accepted in present form.
Reply: We would like to thank the reviewers for their precious time and invaluable comments.
Author Response File: Author Response.docx
