Effect of Different Ratios of Red and Blue Light on Maximum Stomatal Conductance and Response Rate of Cucumber Seedling Leaves
Round 1
Reviewer 1 Report
The research presented herein is interesting. The issue of water use efficiency while maintaining the best photosynthetic parameters and plant growth is extremely important in an environment where plants are exposed to water shortages and rising temperatures. It has long been known that light is an essential factor in regulating the mechanism of stomatal opening. Both blue and red lights are physiologically and morphologically active. However, the signal transduction pathways involved are different. The ratio of blue to red light intensity in the environment can significantly affect stomatal development and movement and further on photosynthesis and plant growth. However, I have found some points that should be corrected:
· In the Introduction, abbreviations L35, 36 should be in brackets
· Line 56: COP1 and PIF4 should be explained
· The experiments were well planned, but a description of the method should be completed. It should be clearly described whether it was hydroponic cultivation and how often the plants were watered.
· Why did the temperature of cultivation differ between the first three days and the remaining days of plant cultivation? 28oC is high. What was the reason for using it?
· Two different descriptions are provided in Figure 1. Please leave only the correct ones.
· L117: FFA, and L174: PPFD should be explained. Please check throughout the manuscript whether all abbreviations are explained when they are first used.
· The authors use the term "cucumber seedlings" (L130, 139 and others). In my opinion, cucumbers growing for more than 25 days are no longer seedlings and should be referred to in the manuscript as "cucumber plants".
· SLAC1 is a nitrate channel/transporter and it should be mentioned in the material and methods. SLAC1 expression levels may indicate the intensity of stomatal movement or efficiency. Moreover, there is no explanation in the text (Results or Discussion) as to why these two genes are used to indicate stomatal development and movement. It should be added.
· L169, there is no number for mention reference
· L183 – what is R160 group?
· The names of the parameters mentioned and described in the text should be the same as indicated in Table 4.
· There are incorrect Figures numbers in the text (L198, L209)
· In Discussion L305 – what are “chloroplast cells”?
Author Response
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Author Response.docx
Reviewer 2 Report
This manuscript describes the effects of different red light/far red light ratios on plant morphology, photosynthesis, and stomatal characteristics. The manuscript is devoted to an interesting and important problem for the scientific community. There is a lot of interesting data presented in the manuscript. However, the quality of data presentation leaves much to be desired. In addition, the manuscript is replete with numerous difficult and incomprehensible statements, as well as jargon and vernaculars.
I have some comments and questions as listed below
Title
What is "R/B"? The reader may not understand what the article is about.
Abstract
I would like the Abstract to contain some conclusion about the work done. To be honest, after reading the abstract, it was very difficult for me to understand what were the main results and impacts of the investigation.
"R/B" should be deciphered.
Preface
Line 34. Can the authors indicate response times/speeds?
Materials and methods
When were different R:B ratios used? It is not clear from the description of the experiment. During cultivation or during measurements?
Line 128. Why was this light intensity chosen?
What is the difference between 2.3.5 and 2.3.3?
Why wasn't the effect of the R/B ratio equal to 0:10 and 10:0 checked?
The Introduction and Materials and methods left a very good impression; however, the further presentation of the material leaves much to be desired.
Results
Table 3. In the "Total leaf area" column, all groups are marked with the letter "b". Why then introduced the letters "a" and "c"? Check for typos. "Fresh weight" column. What is the "d" for? Column "Plant height". Why is the letter "bc" present? Values are usually given with an accuracy of three significant digits. For example, “492.935” should be changed to “493”, “6.143” should be changed to “6.14”. Please, check.
The same problems in table 4 and Figure 2 and 3.
Line 184. You cannot write that " dry weight … decreased compared to R:B=7:3 treatment" if there are no statistically significant differences. In this case, there is no decrease in the parameter.
Too short paragraphs. The results are described somewhat schematically.
All subheadings contain the phrase "Effect of different red and blue light ratios". I would like to note that the entire manuscript is devoted to this. I recommend revising the names of subheadings, and even better get rid of numerous small paragraphs that have their own heading.
Line 209. "… to a certain extent…" How much?
Fig. 4 and Fig. 5. It seems that for the 1:9 curve, the light was switched on earlier than for the others. Please indicate the moment when the light is turned on in the figures.
Fig. 4. What do the gray boxes in the picture mean? Indicate this in the figure caption.
What is figure 5b used for?
Discussion
The discussion is written a little confusingly and needs to be improved.
Lines 267-268. "… combination of red and blue light…" What combination?
Line 273. References about the effect of UV-A radiation must be provided? For example, https://doi.org/10.3389/fpls.2020.601478
Line 274. "within certain limits" should be deleted.
Line 277. "… photosynthetic efficiency was highest when both PSI and PSII were activated and in equilibrium..." What did you mean by that?
Lines 321-323. A very difficult phrase. It is recommended to rewrite.
Lines 324-325. Incomprehensible sentence. Please rewrite.
Lines 326-328. Incomprehensible sentence. Please rewrite.
Lines 329-330. "cucumber seedlings … have greater photosynthetic potential than the … treatment". Please rewrite.
Lines 332-333. Why is there one sentence per paragraph?
To date, a lot of articles have been published on the effect of blue and red light, as well as their ratio, on plants, including the functioning of stomata. Please indicate the novelty of the obtained results more clearly in your manuscript. Underline, what is the main dignity of the work? Please continue the following sentence: “In this work, it was shown for the first time that ...”
Conclusion
Line 344. "responded faster than under R/B" Responded to what?
Based on your data, what R/B ratio would you recommend for farmers?
Despite the manuscript contains some interesting results, manuscript have to be revised before making a decision on the publication in the Journal.
Author Response
Please see the attachment
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
Reviewer comments are marked in blue
Response To Reviewer2 Comments
This manuscript describes the effects of different red light/far red light ratios on plant morphology, photosynthesis, and stomatal characteristics. The manuscript is devoted to an interesting and important problem for the scientific community. There is a lot of interesting data presented in the manuscript. However, the quality of data presentation leaves much to be desired. In addition, the manuscript is replete with numerous difficult and incomprehensible statements, as well as jargon and vernaculars.
I have some comments and questions as listed below
Title
Q1:What is "R/B"? The reader may not understand what the article is about.
A1:It represents the ratio of red light intensity to blue light. The title was modified to “Effect of different ratios of red and blue light on maximum stomatal conductance and response rate of cucumber seedling leaves”.
OK
Abstract
Q2:I would like the Abstract to contain some conclusion about the work done. To be honest, after reading the abstract, it was very difficult for me to understand what were the main results and impacts of the investigation.
A2:It has been changed.
OK
Q3:"R/B" should be deciphered.
A3:It is deciphered as”ratios of red and blue light”.
OK
Q4:Line 34. Can the authors indicate response times/speeds?
A4:In response to this, changes have been made in the article.Explanation in detail of stomatal response times/speeds in 2.4.
OK
Materials and methods
Q5:When were different R:B ratios used? It is not clear from the description of the experiment. During cultivation or during measurements?
A5:The same light was used in the experimental cultivation of cucumber seedlings and in the measurements of stomatal movement, and it with the same intensity and quality of light.
OK
Q6:Line 128. Why was this light intensity chosen?
A6:The experimental light intensity was 220-230 μmol-m-2 s-1 in Dezhi J et al. and 180 μmol-m-2 s-1 in white light in Zhengnan Y et al.So it is reasonable to choose a light intensity of 200 μmol-m-2 s-1 in this trial.
[1]Dezhi J ,Xiaofeng S ,Yuefeng L , et al. Effect of Red and Blue Light on Cucumber Seedlings Grown in a Plant Factory[J]. Horticulturae,2023,9(2).
[2]Zhengnan Y ,Chunling W ,Long W , et al. The Combinations of White, Blue, and UV-A Light Provided by Supplementary Light-Emitting Diodes Promoted the Quality of Greenhouse-Grown Cucumber Seedlings[J]. Agriculture,2022,12(10).
Why was a light intensity of 1000 μmol photons m-2 s-1 chosen to measure photosynthetic activity? Saturating light must be used. Usually 1000 μmol photons m-2 s--1 is not enough
Moreover, "μmol-m-2 s-1" should be changed to "μmol photons m-2 s-1" throughout the text.
Q7:What is the difference between 2.3.5 and 2.3.3?
A7:2.3.3 was the determination of photosynthesis-related traits in cucumber seedlings under saturated light intensity (R90B10;1000 µmol-m-2 -s-1 ).2.3.5 was the determination of stomatal conductance and photosynthesis in cucumber seedlings under environmental light(Light quality varies according to environmental light;200 µmol-m-2 -s-1).
Please describe it in the manuscript more clearly
Q8:Why wasn't the effect of the R/B ratio equal to 0:10 and 10:0 checked?
A8:It has been proved by previous studies that single red light and single blue light are not favorable to the growth of cucumber seedlings[1-2]. The effect of single light quality on stomata has been studied[3].
[1]Claypool Nicholas B,Lieth J Heinrich. Green Light Improves Photosystem Stoichiometry in Cucumber Seedlings (Cucumis sativus) Compared to Monochromatic Red Light.[J]. Plants (Basel, Switzerland),2021,10(5).
[2]Song Jinxiu,Meng Qingwu,Du Weifen,He Dongxian. Effects of light quality on growth and development of cucumber seedlings in controlled environment[J]. INTERNATIONAL JOURNAL OF AGRICULTURAL AND BIOLOGICAL ENGINEERING,2017,10(3).
[3]Chen Jiyu,Gao Jing,Wang Qi,Tan Xianming,Li Shenglan,Chen Ping,Yong Taiwen,Wang Xiaochun,Wu Yushan,Yang Feng,Yang Wenyu. Blue-Light-Dependent Stomatal Density and Specific Leaf Weight Coordinate to Promote Gas Exchange of Soybean Leaves[J]. Agriculture,2022,13(1).
OK
The Introduction and Materials and methods left a very good impression; however, the further presentation of the material leaves much to be desired.
Results
Q9:Table 3. In the "Total leaf area" column, all groups are marked with the letter "b". Why then introduced the letters "a" and "c"? Check for typos. "Fresh weight" column. What is the "d" for? Column "Plant height". Why is the letter "bc" present? Values are usually given with an accuracy of three significant digits. For example, “492.935” should be changed to “493”, “6.143” should be changed to “6.14”. Please, check.The same problems in table 4 and Figure 2 and 3.
A9:In Table 3, there is an inconsistency in the number of valid numbers in the table, and we have improved it by retaining the numbers in the table uniformly to three decimal places. This makes the whole article uniform.We changed the vertical coordinates of Fig 2 to make the number of decimal places consistent.
The problem with superscript letters is not completely fixed (Table 3 and Table 4)
Specifying more than three significant digits does not make sense. Table is hard to read.
Q10:Line 184. You cannot write that " dry weight … decreased compared to R:B=7:3 treatment" if there are no statistically significant differences. In this case, there is no decrease in the parameter.
Too short paragraphs. The results are described somewhat schematically.
All subheadings contain the phrase "Effect of different red and blue light ratios". I would like to note that the entire manuscript is devoted to this. I recommend revising the names of subheadings, and even better get rid of numerous small paragraphs that have their own heading.
A10:We deleted this description and changed the subheading.
OK
Q11:Line 209. "… to a certain extent…" How much?
A11:We deleted this description.
OK
Q12:Fig. 4 and Fig. 5. It seems that for the 1:9 curve, the light was switched on earlier than for the others. Please indicate the moment when the light is turned on in the figures.
Fig. 4. What do the gray boxes in the picture mean? Indicate this in the figure caption.
What is figure 5b used for?
A12:We maintained uniformity across treatments with illumination at 20min.For the time when the lights are switched on we add in the figure notes. The grey box in Figure 4 indicates being in the dark. Figure 5b shows the curvature of the points in Figure 5a.
I don't think that Figure 5b improves the perception of the data presented in Figure 5a.
Discussion
Q13:The discussion is written a little confusingly and needs to be improved.
Lines 267-268. "… combination of red and blue light…" What combination?
A13:It has been changed to”plants grown under single red or blue light were worse than mixed red and blue light ”.
OK
Q14:Line 273. References about the effect of UV-A radiation must be provided? For example, https://doi.org/10.3389/fpls.2020.601478
A14:It's not necessary.We deleted this description.
Removing text instead of correcting it is not the best choice.
Q15:Line 274. "within certain limits" should be deleted.
A15:We deleted this description.
OK
Q16:Line 277. "… photosynthetic efficiency was highest when both PSI and PSII were activated and in equilibrium..." What did you mean by that?
A16:Higher levels of photosynthetic capacity are achieved when PSI and PSII efficiencies are high and in equilibrium. Changes have been made to the description in the article
Unclear
Q17:Lines 321-323. A very difficult phrase. It is recommended to rewrite.
Lines 324-325. Incomprehensible sentence. Please rewrite.
Lines 326-328. Incomprehensible sentence. Please rewrite.
A17:It has been changed.
OK
Q18:Lines 329-330. "cucumber seedlings … have greater photosynthetic potential than the … treatment". Please rewrite.
A18:It has been changed.
OK
Q19:Lines 332-333. Why is there one sentence per paragraph?
A19:It has been changed.
OK
Q20:To date, a lot of articles have been published on the effect of blue and red light, as well as their ratio, on plants, including the functioning of stomata. Please indicate the novelty of the obtained results more clearly in your manuscript. Underline, what is the main dignity of the work? Please continue the following sentence: “In this work, it was shown for the first time that ...”
A20:It was added to "Conclusion".In this work, it was shown for the first time that the rate of stomatal movement in plants under mixed red and blue light.
Incomprehensible sentence. Please rewrite.
Conclusion
Q21:Line 344. "responded faster than under R/B" Responded to what?
A21:It has been changed.Responded to high R/B.
OK
Q22:Based on your data, what R/B ratio would you recommend for farmers?
A22:The significance of this trial is explained in terms of "leads to match between stomatal conductance (gs) and carbon assimilation (A)''. It can be applied to the fact that when plants are in the early morning, increasing the proportion of blue light in the light will be more favourable to the rapid opening of stomata. Because stomatal opening is much slower than the rate at which plants begin to photosynthesise, this time period would result in the rate of plant gas exchange limiting photosynthetic capacity.So the recommendation is R:B = 1:9
Despite the manuscript contains some interesting results, manuscript have to be revised before making a decision on the publication in the Journal.
The sections "Results" and "Discussion" are practically not improved. An additional revision of the manuscript is required.
