Changes in Spectral Reflectance, Photosynthetic Performance, Chlorophyll Fluorescence, and Growth of Mini Green Romaine Lettuce According to Various Light Qualities in Indoor Cultivation

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Reviewer

 

Changes in Spectral Reflectance, Photosynthetic Performance, and Chlorophyll Fluorescence of Mini Green Romaine Lettuce according to Various Light Qualities in Indoor Cultivation. Below are presented my suggestions in blue.

Lane 16: To change by: depending on the combination of an artificial light source

 

Lane 21: Indicate the meaning of BR-Led in word

Lane 24:  Indicate with word the meaning of  QD-LED,

 

Lane 47: to change by: Blue light, is primarily used to promotes the photosynthesis process, pigment production, and chloroplast development….

 

Lane 87. To change by: This method allows a the rapid evaluation of plant…..

 

Lane 110: To change by: compared to grown under 100% red light alone…..

 

Lane 129: At the end of the sentence, improve the wording to indicate that you are talking about the four phases.

 

Lane 146: Improve the wording of: In addition, research is currently being conducted on chlorophyll fluorescence, which varies depending on factors such as the environmental conditions, stress, and nutrient solution of various crops (Spanic et al., 2021; Zhu et al., 2021; Lima-Moro et al., 2022)

 

Lane 171: to change dedicated by specific

 

 

Please, improve the quality of figure 3. In addition, indicate in the text of manuscript or in the figure legend the statistical differences between each treatment performed, indicate that it is a, b, c etc. (the p value)

 

Finally, the manuscript is well written, clearly describing as the spectral reflectance, photosynthetic yield, chlorophyll fluorescence, and growth changes when romaine mini green lettuce was grown hydroponically indoors under various lighting sources. The article is interesting and should be published.

 

Can be accepted  with minor corrections

Comments on the Quality of English Language

Well written, there are only small errors that can be improved.

Author Response

1^ST Reviewer

1) Reviewer’s comment:

Line 16: To change by: depending on the combination of an artificial light source.

Author’s response: It has been revised according to the reviewer's comments.

[Before correction]
Light quality can be stated to be the identity of an artificial light source, and although the response of light quality may vary depending on the crop, the effect is clearly visible and can produce various results depending on the combination.

[After correction]
Light quality can be stated to be the identity of an artificial light source, and although the response of light quality may vary depending on the crop, the effect is clearly visible and can produce various results depending on the combination of an artificial light source.

 

2) Reviewer’s comment:

Line 21: Indicate the meaning of BR-Led in word

Author’s response: It has been revised according to the reviewer's comments.

[Before correction]
Most parameters related to spectral reflectance showed the best results under blue light, and photosynthetic performance was more effective with mixed light than with single-colored light, among which BR-LED was the most suitable.

[After correction]
Most parameters related to spectral reflectance showed the best results under blue light, and photosynthetic performance was more effective with mixed light than with single-colored light, among which blue + red (BR)-LED was the most suitable.

 

3) Reviewer’s comment:

Line 24: Indicate with word the meaning of QD-LED,

Author’s response: It has been revised according to the reviewer's comments.

[Before correction]
In the case of chlorophyll fluorescence, the light quality influenced photomorphogenesis, resulting in increased leaf length and width with R and QD-LED, which expanded the leaf area and allowed for more external light to be captured (ABS/RC, TRo/RC).

[After correction]
In the case of chlorophyll fluorescence, the light quality influenced photomorphogenesis, resulting in increased leaf length and width with R- and quantum dot (QD)-LED, which expanded the leaf area and allowed for more external light to be captured (ABS/RC and TRo/RC).

 

4) Reviewer’s comment:

Line 47: to change by: Blue light, is primarily used to promotes the photosynthesis process, pigment production, and chloroplast development….

Author’s response: The sentence itself has been revised based on comments from other reviewers.

[Before correction]
Blue light, which is primarily used in photosynthesis, promotes the photosynthesis process, pigment production, and chloroplast development, but it is also said to inhibit growth. Red light, on the other hand, shows the opposite tendencies.

[After correction]

Blue light was found to reduce plant size but increase chloroplast abundance, while red light increased shoot biomass, hypocotyl and cotyledon elongation, and leaf area. How-ever, it was also noted that a deficiency of specific wavelengths, such as under mono-chromatic blue or red light, can severely impair plant development in terms of morphology and physiology

5) Reviewer’s comment:

Line 87: To change by: This method allows a the rapid evaluation of plant…..

Author’s response: It has been revised according to the reviewer's comments.

[Before correction]
This method allows for the rapid evaluation of plant health indicators such as pigments, nitrogen content, and moisture levels, without the need for multiple stages, making it advantageous.

[After correction]

This method allows a the rapid evaluation of plant health indicators such as pigments, nitrogen content, and moisture levels, without the need for multiple stages, making it advantageous.

 

6) Reviewer’s comment:

Line 110: To change by: compared to grown under 100% red light alone…..

Author’s response: It has been revised according to the reviewer's comments.

[Before correction]
compared to when grown under 100% red light alone, and it was suggested that appropriately combining red and blue light spectra in BR-LED lighting is more conducive to enhancing photosynthetic performance in soybeans than using red or blue light alone

[After correction]

compared to grown under 100% red light alone, and it was suggested that appropriately combining red and blue light spectra in BR-LED lighting is more conducive to enhancing photosynthetic performance in soybeans than using red or blue light alone.

 

7) Reviewer’s comment:

Line 129: At the end of the sentence, improve the wording to indicate that you are talking about the four phases.

Author’s response: It has been revised according to the reviewer's comments.

[Before correction]
The "O" stage (origin) refers to the point of fluorescence induction when chlorophyll returns to its original state after a dark period of approximately 15 minutes to 1 hour, and the "J" stage (jump) denotes the first minimal fluorescence variation following the "O" stage. Next, the intermediate fluorescence level is referred to as the "I" stage (intermediate), and finally, the fluorescence induction amount at the maximum fluorescence level is called the "P" stage (peak).

[After correction]

In O-J-I-P, the "O" stage (origin) refers to the point of fluorescence induction when chlorophyll returns to its original state after a dark period of approximately 15 minutes to 1 hour, and the "J" stage (jump) denotes the first minimal fluorescence variation following the "O" stage. Next, the intermediate fluorescence level is referred to as the "I" stage (intermediate), and finally, the fluorescence induction amount at the maximum fluorescence level is called the "P" stage (peak).

 

8) Reviewer’s comment:

Line 146: Improve the wording of: In addition, research is currently being conducted on chlorophyll fluorescence, which varies depending on factors such as the environmental conditions, stress, and nutrient solution of various crops (Spanic et al., 2021; Zhu et al., 2021; Lima-Moro et al., 2022)

Author’s response: It has been revised according to the reviewer's comments.

[Before correction]
In addition, research is currently being conducted on chlorophyll fluorescence, which varies depending on factors such as the environmental conditions, stress, and nutrient solution of various crops

[After correction]

Additionally, ongoing research is focusing on chlorophyll fluorescence, which varies based on factors like environmental conditions, stress, and nutrient solutions for various crops

9) Reviewer’s comment:

Line 171: to change dedicated by specific, please, improve the quality of figure 3. In addition, indicate in the text of manuscript or in the figure legend the statistical differences between each treatment performed, indicate that it is a, b, c etc. (the p value)

Author’s response: It has been revised according to the reviewer's comments (Figure3, Figure 10).

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The paper studied the effect of different light qualities and their combinations (blue and red light wavelengths) on spectral reflectance, photosynthetic performances, chlorophyll fluorescence and growth parameters of mini green romaine lettuce.

The paper is very interesting and generally well- written, with sporadic punctuation, or format errors.

In detail:

-Title could include also the growth parameter which were also investigated

-Abstract might be improved by including the detail of light treatments used in this study.

-Introduction is complete but quite long. Moreover, it should be useful to explain more deeply the reason why the sole combination of BR-LED light (80B:20R) was chosen for this study, by adding more references about lettuce if present.

-Figures and the including headings are quite small and difficult to read

-Results and discussion are generally quite clear and rich in term of analyses.

-Please, check the list of reference and the journal guidelines for the references along the text and the references list.

Author Response

2^ND Reviewer

1) Reviewer’s comment:

Line 1: Title could include also the growth parameter which were also investigated.

Author’s response: It has been revised according to the reviewer's comments.

[Before correction]
Changes in Spectral Reflectance, Photosynthetic Performance, and Chlorophyll Fluorescence of Mini Green Romaine Lettuce according to Various Light Qualities in Indoor Cultivation

[After correction]
Changes in Spectral Reflectance, Photosynthetic Performance, Chlorophyll Fluorescence, and Growth of Mini Green Romaine Lettuce according to Various Light Qualities in Indoor Cultivation

 

2) Reviewer’s comment:

Line 16: Abstract might be improved by including the detail of light treatments used in this study.

Author’s response:

I believe that the detailed information about the lighting treatment used in this study is too extensive to be added to the abstract and that the explanation provided in the introduction is sufficient.
Thank you for your comments, reviewer.

 

3) Reviewer’s comment:

Line : Introduction is complete but quite long. Moreover, it should be useful to explain more deeply the reason why the sole combination of BR-LED light (80B:20R) was chosen for this study, by adding more references about lettuce if present.

Author’s response:

I believed it was important for the introduction to provide the essential information needed to understand this paper, so I wrote it in detail.
In the case of BR-LEDs, it is known that the response of the same crop can vary depending on the ratio of blue to red light. The reason for setting the BR-LED ratio to 80B:20R in this study is that the BR-LEDs currently set up in our laboratory growth chamber are configured at 80B:20R. Based on various papers, we determined that the 80B:20R ratio would be suitable for growing lettuce, so we proceeded with this configuration.
While writing this paper, I reviewed various references, but unfortunately, there were fewer studies on lettuce that I could directly refer to than I had expected. For this reason, I hope that this study will be of great help to other researchers. Additionally, because I wanted to document the responses of various crops to different light qualities, I also referred to results from crops other than lettuce.
Thank you for your comments, reviewer.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors The article is interesting, gathers a lot of information and is a good example of finding correlations. It is necessary to correct some spelling inaccuracies and arrange the references.Recommendations are in the attached file.

Comments for author File: Comments.pdf

Author Response

3^RD Reviewer

1) Reviewer’s comment:

Line 60: Adding 700nm to far red is debatable

Author’s response: It has been revised according to the reviewer's comments.

[Before correction]
These QD-LEDs exhibit the Emerson enhancement effect, whereby they can achieve a higher photosynthetic efficiency compared to the sum of the individual photosynthetic rates obtained when red light (680nm) and far-red light (700nm) are investigated independently.

[After correction]
These QD-LEDs exhibit the Emerson enhancement effect, whereby they can achieve a higher photosynthetic efficiency compared to the sum of the individual photosynthetic rates obtained when red light and far-red light are investigated independently.

 

2) Reviewer’s comment:

Line 197: Figure 2: What does 3EA or 4EA mean?

Author’s response:

"3EA and 4EA" refer to the number of LEDs installed per layer in the growth chamber. The explanation is provided below (line: 197-198).

3) Reviewer’s comment:

Line 348: That was already in the methodology.

Author’s response:

The duplicated parts have been deleted.

4) Reviewer’s comment:

Line 359: Where is R-LED?

Author’s response:

The results for that section represent the ranking outcomes of treatments (QD, BR, W, B), excluding the R-LED, which showed different trends in fluorescence intensity graphs. The results for R-LED were explained separately in the preceding sentences.

5) Reviewer’s comment:

Line 360: What light intensity?

Author’s response:

The OJIP graph is measured as the light intensity gradually increases through the stages. This information is already included in the text (line: 354-356).

6) Reviewer’s comment:

Line 444: This is an assumption. Fig 6 shows that transpiration is reduced.

Author’s response: It has been revised according to the reviewer's comments.

[Before correction]
These results suggest that cultivating lettuce under R-LED promotes water uptake from the roots, enhancing growth; it also indicates that increased water absorption in the roots contributes to overall plant development.

[After correction]
These results are stated to be due to the lower transpiration rate of lettuce grown under red light compared to the other treatments, as shown in the transpiration rate results in Figure 6.

 

7) Reviewer’s comment:

Line 772: area

Author’s response: It has been revised according to the reviewer's comments.

[Before correction]
However, in the case of QD-LED, the blue light was the same as BR-LED at 24%, and the red light area ratio was also the same, but it showed the lowest photosynthesis performance after R-LED (Table 3).

[After correction]
However, in the case of QD-LED, the blue light was the same as BR-LED at 24%, and the red light ratio was also the same, but it showed the lowest photosynthesis performance after R-LED (Table 3).

 

8) Reviewer’s comment:

Line 561, 700, 723, 730,887, 896

Author’s response: All italics, uppercase, lowercase, superscript and subscript corrections have been corrected.

 

9) Reviewer’s comment:

Line 761: far-red region (λ > 700 nm) Decide where 700nm belongs

Author’s response: I think there will be no problem if the ambiguous part in the introduction (Line: 60) is deleted.

Author Response File: Author Response.docx

Reviewer 4 Report

Comments and Suggestions for Authors

Dear Authors

That article is really interesting and well-prepared. I appreciated that the authors provided a detailed analysis of various physiological (fluorescence, photosynthesis) and biometric parameters, as well as the correlations between them. The article also effectively explained the results in a logical and precise manner. It was good to see the confirmation of known facts such as the inefficiency of growing crops under monochromatic lights and the lack of correlation between certain physiological parameters and the yield obtained.

In the conclusion chapter, the authors should add practical recommendations under which light mini romaine lettuce plants are best grown at this light intensity. In addition, I think, that in continuing this very interesting research, it is worthwhile to also pay attention to the nutritional value of lettuce, which is also significantly influenced by light colour.  In the article in question, a lower water content in the leaves could mean a higher amount of active compounds and a higher nutritional value.

The authors should also adapt the way they cite to the requirements of the journal.

Detailed comments in the text.

Comments for author File: Comments.pdf

Author Response

4^TH Reviewer

1) Reviewer’s comment:

Line 22-32: Please don’t use only abbreviations first time, also in the abstract.

Author’s response: It has been revised according to the reviewer's comments.

[Before correction]
QD-LED, BR-LED, R-LED, B-LED

[After correction]
quantum dot (QD)-LED, blue + red (BR)-LED, red (R)-LED, blue (B)-LED

 

2) Reviewer’s comment:

Line 34: In keywords you should put thew words another than in the title.

Author’s response: It has been revised according to the reviewer's comments.

[Before correction]
Keywords: Chlorophyll Fluorescence; Light quality; Mini romaine lettuce; Photosynthetic Performance; Spectral Reflectance

[After correction]
Keywords: Light quality, OJIP, Photomorphogenesis, PI_ABS, Photosynthetic rate

 

3) Reviewer’s comment:

Line 49: It follows from this sentence that red light has characteristics opposite to blue light, which is not true.

Author’s response: It has been revised according to the reviewer's comments.

[Before correction]
Blue light, is primarily used to promotes the photosynthesis process, pigment production, and chloroplast development, but it is also said to inhibit growth. Red light, on the other hand, shows the opposite tendencies

[After correction]
Blue light was found to reduce plant size but increase chloroplast abundance, while red light increased shoot biomass, hypocotyl and cotyledon elongation, and leaf area. How-ever, it was also noted that a deficiency of specific wavelengths, such as under mono-chromatic blue or red light, can severely impair plant development in terms of morphology and physiology

 

4) Reviewer’s comment:

Line 135: the same paragraph for the first two sentence, please

Author’s response: It has been revised according to the reviewer's comments.

5) Reviewer’s comment:

Line 162: please add the latin name of lettuce

Author’s response: It has been revised according to the reviewer's comments.

[Before correction]
(cv. Minicup, ASIA SEED KOREA)

[After correction]

(Lactuca sativa cv. Minicup, ASIA SEED KOREA)

 

6) Reviewer’s comment:

Line 368: please try to change the color of the individual lines a little to make them more readable

Author’s response: The color of each line represents the color of the light, so I didn't change it. Thanks for the nice comment.

Author Response File: Author Response.docx