Effect of Selenium Application on Growth, Antioxidative Capacity, and Nutritional Quality in Purple Lettuce Seedlings

Round 1

Reviewer 1 Report

I add my suggestions below:

Line 17: Lactuca sativa L. var. crispa or capitata or ? Which? Is "purple rome" a variety?

Line 42: Plant Se is not entirely clear.

Line 48: content or concentration? 
example?

Line 69: a literature on what dose inhibits?

Line 107: Were the climatic characteristics of the greenhouse recorded? It can affect the nutrition and content of lettuce.

Line 111: What is it? what does it represent?

Line 115-117: How long did the research take? Is it only repeated once? Repeated separately for two season or two years or two?

When did the research begin?

Line 147: What does the word "Shoots" represent? leaf, seedling, head of lettuce?

Line 210: ? what does it show? is it true?

Line 213: 12?

Line 219-224: The figure is too long for the description. some material method information. Other figures should also be checked.

Line 279: content or concentration?

Line 337: Do you own these studies?

Line 345: instructions to the authors? There are a few misspellings like this one.

Line 413: So what dose of se do you recommend?

Author Response

We are very grateful for your suggestions and those of the reviewers. Point-by-point responses to the Reviewer 1 Comments are provided below in word file.

Author Response File: Author Response.docx

Reviewer 2 Report

The article studies the biofortification with Se of lettuce. The novelty of the study lies in the histochemical analysis and in the expression of an enzyme of the anthocyanin synthesis pathway. The rest of the analyzed parameters have already been extensively addressed in other published works on lettuce biofortification at different concentrations of both selenite and selenite. ,

Questions to answer:

1-The experimental design does not seem correct to me when using pure water as a growth base in lettuce cultivation. After 3 weeks with only water the plants are probably deficient in essential mineral elements. Where is the analysis of these elements, the biomass and length of these plants? What have they been used for?

2-How many days have the lettuce seedlings required to germinate?

3-Specify in the material and methods the exposure time of the samples that have been used for each analysis (3, 6 days or 3 weeks).

4-Detail the exposure time in section 3.5. and in figure 5.

5-Section 2.7. It cannot be called "nutrient determination" because Se is not an essential nutrient for the plant and neither can sugars, proteins, etc. be considered nutrients. It would be better to talk about "Se and other compounds analyzed".

The introduction and conclusions are based on the ingestion of this biofortified lettuce but this culture is ingested after many more days of culture than the 3 and 6 days determined in this study. This implies that the results of the compounds analyzed in such a short term can be very different at real culture times.

Author Response

We are very grateful for your suggestions and those of the reviewers. Point-by-point responses to the Reviewer 2 Comments are provided below in word file.

Author Response File: Author Response.docx

Reviewer 3 Report

Dear Editor and Authors, thank you for the possibility to hear me. I fell me honored. I liked very much of this study. It is very well presented as I appointed in questions before.

There are some observations that I wrote in manuscript. But, my main issue (line 203) is about the harvest times to perform the evaluations.  I do not understand. It is very confusing to me. It was said (line 116-117) that the samples were taken at 3 days, 6 days and 3 weeks after starting the treatments. For the major of the characteristics presented (it was read in footnote of the figures) there is only results of 3 days afetr treatments. Was only root lenght evaluated at 3 and 6 days? And after 3 weeks, was not? And the other characteristcs at 6 days and 3 weeks?

I believe to be very, very important a better wrinting about this in the item M & M. It would be very interesting to clarify whether all the characteristics were evaluated in the three harvest times or not. Another possibility is to explain in each characteristic when it was evaluated.

Comments for author File: Comments.pdf

Author Response

We are very grateful for your suggestions and those of the reviewers. Point-by-point responses to the Reviewer 3 Comments are provided below in word file.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

My previous revised suggestions have been corrected. The article has become more understandable. However, I still could not find any information about how long the research took. When did it start, when did it end, how long did it last, how many days?

Line: 122: How long do three biological replicates take? Is this agrowing season?

Comments for author File: Comments.pdf

Author Response

We are very grateful for your suggestions from the reviewer. Point-by-point responses to Reviewer 1 Comments are in a Word file below.

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript has been improved but there is a problem with the word "content" from sections 2.4. Malondialdehyde (MDA) Content, 2.7.1. Se Content, 2.7.2. Total Soluble Protein Content, 2.7.3. Total Soluble Sugar Content, 2.7.4. Anthocyanin Content, 2.7.5. Vitamin C Content and the legend of figure 4.  I think that it is not content but concentration since the authors took a part of the tissue of the plants and not all the tissue. Please, review all the text (discussion) and change these words (ex: line 314, 317, 323....) using amount, level, value...but not content.

Round 3

Reviewer 1 Report

Thank you