Round 1

Reviewer 1 Report

This manuscript reports foliar application of nanoparticles doped with MeJ (ACP-MeJ) and foliar application of methyl jasmonate (MeJ) on aroma volatile composition of grapes. Overall, this is a useful study for improving grape aroma and the findings should be of high value for the application of nanoparticles to promote fruit aromatic quality.

 

Major comments.

1. This study conducted during two consecutive vintages, while there are some opposite results between these two seasons? For example, ACP-MeJ increased the amount in the grapes of total terpenoids, and total benzenoid compounds in 2020, whereas decreased the content of total terpenoids, total benzenoid compounds in 2019. Why? The authors should discuss the potential causes.

 

2. Since nanoparticles can be transported among different tissues and organs in plant, did the authors test the ACP-MeJ nanoparticle residues in grape berries after harvest?  Is there any potential health risk of nanoparticles in grape fruits for producing musts or wine?

 

3. Why did not set up a treatment of nanoparticles without MeJ. Compared with ACP-MeJ, this treatment can determine the effect of nanoparticles on grape volatile compounds. Many studies have showed that nanoparticles can exert some effects on plants.

 

4. Although the treatment MeJ and ACP-MeJ enhanced the grape volatile composition, methyl jasmonate is very high cost and with low chemical stability. Can the authors provide an evaluation of cost estimates in applying methyl jasmonate on a large-scale use in vineyard?

 

Minor comments.

 

Line 32，what “The volatile compounds”？Did you mean grape volatile compounds？

 

Why “Tempranillo” grapes were selected for this study?

 

Introduction. This paper is about grape aroma study, however, there is no any background / introduction of fruit aroma and grape aroma in Introduction section. I list a recent review of fruit aroma for authors’ reference. “Floral Scents and fruit aromas: functions, compositions, biosynthesis, and regulation, Frontiers in Plant Science, 2022, 13:860157”.

Author Response

MANUSCRIPT applsci-2174316

 

RESPONSE TO REVIEWER 1 AND CHANGES WE HAVE MADE TO THE MANUSCRIPT

Firstly, please accept our thanks for the comments you have made on our paper. Your suggestions have helped to improve the quality of the paper. We hope that the answers outlined below and the changes we have made to the text will be satisfactory.

 

This manuscript reports foliar application of nanoparticles doped with MeJ (ACP-MeJ) and foliar application of methyl jasmonate (MeJ) on aroma volatile composition of grapes. Overall, this is a useful study for improving grape aroma and the findings should be of high value for the application of nanoparticles to promote fruit aromatic quality.

 

We thank the reviewer for his/her positive comments.

 

Major comments.

• This study conducted during two consecutive vintages, while there are some opposite results between these two seasons? For example, ACP-MeJ increased the amount in the grapes of total terpenoids, and total benzenoid compounds in 2020, whereas decreased the content of total terpenoids, total benzenoid compounds in 2019. Why? The authors should discuss the potential causes.

 

Page 12, lines 334-339: Following the reviewer's recommendations, a sentence has been added explaining the possible reasons for the difference between vintages.

 

• Since nanoparticles can be transported among different tissues and organs in plant, did the authors test the ACP-MeJ nanoparticle residues in grape berries after harvest? Is there any potential health risk of nanoparticles in grape fruits for producing musts or wine?

 

In this case, the residue remaining in the berries after application was not studied, since all the berries collected were used to measure the different quality parameters of the grapes, such as general parameters, amino acids, phenolic compounds, or volatile compounds. In a previous study, the foliar application of ACP-MeJ (also named as nano-MeJ or nanoelicitor) during veraison ended up with the precipitation of nanostructured aggregates on the surface of the leaves (see figure below). These aggregates retained the elicitor and provided a prolonged and sustained supply of the elicitor through the leaves, causing the efficiency increase observed with the nano-MeJ treatments in the in vivo field experiments (reference 31). Nonetheless, the nanoparticles were not observed in the grape berries.

Respect to the potential health risk, amorphous calcium phosphate nanoparticles (ACP-NPs) are non-toxic and biocompatible nanomaterials widely used in biomedicine for drug delivery, dental remineralization or bone tissue engineering (reference 32). Recently, due to its composition rich in calcium and phosphate, two of the major plant nutrients, ACP-NPs have been proposed as potential nanocarrier to enhance plant growth and protection (reference 23). In the case of ACP-MeJ, its citotoxity has been previously studied in mouse skin melanoma (B16-F10) and human embryonic kidney (HEK293) cell lines showing less toxicity than free MeJ in both cases (reference 31). In the case of melanoma cells, the half-maximal inhibitory concentration (IC₅₀ value) of free MeJ was 2.2 mM whereas this value increased up to 4.7 mM for ACP-MeJ, indicating its lower associated toxicity. HEK-293 also showed a higher IC₅₀ value for ACP-MeJ than for free MeJ, being 3.8 and 2.9 mM, respectively. The lower toxicity of MeJ coupled to ACP nanoparticles is remarkably advantageous for the safe handling and use of MeJ in agriculture, representing less health risk than the conventional foliar application of free MeJ.

 

 

• Why did not set up a treatment of nanoparticles without MeJ. Compared with ACP-MeJ, this treatment can determine the effect of nanoparticles on grape volatile compounds. Many studies have showed that nanoparticles can exert some effects on plants.

 

The study suggested by the reviewer can be very interesting, however, the objective of this work is to compare the effect of MeJ with ACP-MeJ, an effective nanocarrier capable to reduce the dosage and so the costs related to the application of MeJ. A previous study focused on the effect of ACP-MeJ on the nitrogen concentration of Monastrell grapes treated with ACP-MeJ and naked nanoparticles revealed that the the concentration of amino acids did not show differences between free or decorating NPs (reference 27).

 

• Although the treatment MeJ and ACP-MeJ enhanced the grape volatile composition, methyl jasmonate is very high cost and with low chemical stability. Can the authors provide an evaluation of cost estimates in applying methyl jasmonate on a large-scale use in vineyard?

 

MeJ price: 467 €/100 grams

Molar mass: 224.29 g/mol

Concentration in our solution: 10 mM the MeJ and 1 mM the ACP-MeJ

Application volume: 200 mL/plant

Calculations:

 

Since the MeJ concentration in ACP-MeJ is 10 times lower, the price per plant would be:

Taking into account that the average density per hectare is 3000 plants, and that an average vineyard has 1.8 ha. The average price would be:

MeJ:

ACP-MeJ:

It can be seen that the difference is enormous, which emphasizes the importance of this study.

 

Minor comments.

Line 32，what “The volatile compounds”？Did you mean grape volatile compound?

 

Line 32: The word grape has been added.

 

Why “Tempranillo” grapes were selected for this study?

 

Our research center is located in La Rioja, Spain, within the Rioja D.O.Ca., and the Vitis vinifera L. cv Tempranillo variety is the most abundant.

Moreover, according to Eurostat, the most cultivated main red varieties in the EU were Tempranillo (13.8 % of all area under main vine varieties for red wine) in 2020 (https://ec.europa.eu/eurostat/statistics-explained/index.php?title=Vineyards_in_the_EU_-_statistics#General_overview)

 

Introduction. This paper is about grape aroma study, however, there is no any background / introduction of fruit aroma and grape aroma in Introduction section. I list a recent review of fruit aroma for authors’ reference. “Floral Scents and fruit aromas: functions, compositions, biosynthesis, and regulation, Frontiers in Plant Science, 2022, 13:860157”.

 

We thank the reviewer for his suggestion, the proposed reference has been added (Line 32, reference 4). However, in the Introduction there are 33 references, of which 1, 3-10, 12, 21, and 32 speak of the aromatic composition of the grape and/or wine.

 

Author Response File: Author Response.docx

Reviewer 2 Report

 General comment

The manuscript ''Changes on grape aroma composition as a consequence of foliar application of methyl jasmonate and nano-sized particles doped with methyl jasmonate'' study the influence of foliar application of nanoparticles doped with methyl jasmonate  and foliar application of methyl jasmonate on volatile composition of Tempranillo grapes (or more precisely Vitis vinifera L. cv. Tempranillo) determined by SPME-GC-MS. Article is well done and it is worth to be published in Applied Science journal after major corrections.

The section Results should be redesigned and authors should try to avoid repetition of results presented in tables and figures. Instead of repetition, they should try to present the most valuable results. It is a pity that such a presentation reduces the interest of the manuscript.

 Minor comments

Line 59: write name of Tempranillo grapes in a botanical correct way through the manuscript, that is after Tempranillo grapes add ''(Vitis vinifera L. 'Tempranillo')'' or ''(Vitis vinifera L. cv. Tempranillo)''

Line 62: the same

Lines 71, 72: add ''in the same period'' after rainfall to be clear that it was not annual precipitation

Lines 70-73: it should be clearly written that the temperature also refers to the same period from April to September

Line 87: change short into long hyphen (short hyphen and symbol for minus are not the same)

Line 95: add space, that is change ''t=0'' into ''t = 0'' (see line 121)

Line 114: change short into long hyphen

Line 131: change title of section that is Results into Results and Discussion

Table 1, title: move ''doped with MeJ (ACP-MeJ) foliar treatments, in 2019'' in the row below

Table 1: Means and standard deviation should be in one row (there is enough space for that). So, the columns should be rearranged

Table 1, column 1: move ''(%'' (after Probable alcohol) in the row below

Table 1: rearrange note below table into three row

Line 153: change short into long hyphen

Line 173: write name of Garnacha cultivar in a botanical correct way, that is Vitis vinifera 'Garnacha'

Line 202: explain abbreviation TDN (it was mentioned here for the first time)

Line 196, 235, 265: please, be careful. The symbol for micrograms was changed during creation of PDF.

Table 2: The columns should be rearranged because means, standard deviation and letters which indicate significant differences between the samples should be in one row (use Landscape orientation if it is necessary). Presented way is confusing.

Table 3, title: move ''studied: treatment (control, MeJ, ACP-MeJ) and'' in the row below

Table 3: Column titles were changed.

Table 3: Means and standard deviation should be in the same row.

Table 3: rearrange note below table into three row

Table 4: change letter ''x'' into symbol ''×''

Line 432: change ''5. Conclusions'' into ''4. Conclusions''

Line 465: change Vitis Vinifera L into Vitis Vinifera L.

Line 480. Check is the reference no. 8 wrote according to the journal style

Line 501: change Vitis Vinifera into Vitis vinifera

Line 512: change Vitis Vinifera into Vitis vinifera

Line 555: change Vitis Vinifera into Vitis vinifera

 

 

 

Author Response

MANUSCRIPT applsci-2174316

 

RESPONSE TO REVIEWER 2 AND CHANGES WE HAVE MADE TO THE MANUSCRIPT

 

Firstly, please accept our thanks for the comments you have made on our paper. Your suggestions have helped to improve the quality of the paper. We hope that the answers outlined below and the changes we have made to the text will be satisfactory.

 

The manuscript ''Changes on grape aroma composition as a consequence of foliar application of methyl jasmonate and nano-sized particles doped with methyl jasmonate'' study the influence of foliar application of nanoparticles doped with methyl jasmonate  and foliar application of methyl jasmonate on volatile composition of Tempranillo grapes (or more precisely Vitis vinifera L. cv. Tempranillo) determined by SPME-GC-MS. Article is well done and it is worth to be published in Applied Science journal after major corrections.

 

We thank the reviewer for his/her positive comments.

 

The section Results should be redesigned and authors should try to avoid repetition of results presented in tables and figures. Instead of repetition, they should try to present the most valuable results. It is a pity that such a presentation reduces the interest of the manuscript.

 

We agree with the reviewer that this section is quite dense, however, it can be observed that when several compounds of the same family follow the same trend, they were grouped and explained simultaneously. Despite that, the section is very extensive due to the large number of results provided (two vintages, 2019 and 2020), with two treatments each (MeJ, and ACP-MeJ), and with a total of 36 compounds spread over up to 7 different families.

 

Minor comments

Line 59: write name of Tempranillo grapes in a botanical correct way through the manuscript, that is after Tempranillo grapes add ''(Vitis vinifera L. 'Tempranillo')'' or ''(Vitis vinifera L. cv. Tempranillo)''

 

Line 61: the name Tempranillo has been corrected to Vitis vinifera L. cv. Tempranillo

 

Line 62: the same

 

Line 65: has been corrected, as well as throughout the manuscript.

 

Lines 71, 72: add ''in the same period'' after rainfall to be clear that it was not annual precipitation

 

Line 75: the sentence "in the same period" has been added.

 

Lines 70-73: it should be clearly written that the temperature also refers to the same period from April to September

 

Lines 72-73: has been moved to make it clear that we refer to all the data provided.

 

Line 87: change short into long hyphen (short hyphen and symbol for minus are not the same)

 

Line 91: the short dash has been replaced by a minus symbol.

 

Line 95: add space, that is change ''t=0'' into ''t = 0'' (see line 121)

 

Line 99: the space has been added.

 

Line 114: change short into long hyphen

 

Line 118: the short hyphen has been changed to the long hyphen.

 

Line 131: change title of section that is Results into Results and Discussion

 

Line 135: thanks to the reviewer for his observation, section 3 has been changed to Results and Discussion.

 

Table 1, title: move ''doped with MeJ (ACP-MeJ) foliar treatments, in 2019'' in the row below

Table 1: Means and standard deviation should be in one row (there is enough space for that). So, the columns should be rearranged

Table 1, column 1: move ''(%'' (after Probable alcohol) in the row below

Table 1: rearrange note below table into three row

Table 1: the size of the table has been modified. We put it this way initially, but it is a journal modification. When changing the size of the table, it is not necessary to make the rest of the changes suggested by the reviewer, since everything appears on the same line, and it adjusts to the size of the table. However, it is possible that the journal will change it again.

 

Line 153: change short into long hyphen

 

Line 157: the short hyphen has been changed to the long hyphen.

 

Line 173: write name of Garnacha cultivar in a botanical correct way, that is Vitis vinifera 'Garnacha'

 

Lines 178-179: Garnacha has been changed to Vitis vinifera 'Garnacha'.

 

Line 202: explain abbreviation TDN (it was mentioned here for the first time)

 

Lines 207-208: the abbreviation TDN has been explained.

 

Line 196, 235, 265: please, be careful. The symbol for micrograms was changed during creation of PDF.

 

The µ symbol has been added.

 

Table 2: The columns should be rearranged because means, standard deviation and letters which indicate significant differences between the samples should be in one row (use Landscape orientation if it is necessary). Presented way is confusing.

 

Table 2: has been set to horizontal.

 

Table 3, title: move ''studied: treatment (control, MeJ, ACP-MeJ) and'' in the row below

Table 3: Column titles were changed.

Table 3: Means and standard deviation should be in the same row.

Table 3: rearrange note below table into three row.

 

Table 3: The complete table has been readjusted. The journal may decide to modify it again for formatting reasons.

 

Table 4: change letter ''x'' into symbol ''×''

 

Table 4: the letter ''x'' has been modified into symbol ''×''.

 

Line 432: change ''5. Conclusions'' into ''4. Conclusions''

 

Line 442: the section number has been changed.

 

Line 480. Check is the reference no. 8 wrote according to the journal style

 

The references have been written with the Mendeley reference manager, using the format suggested by the journal.

 

Line 501: change Vitis Vinifera into Vitis vinifera

Line 512: change Vitis Vinifera into Vitis vinifera

Line 555: change Vitis Vinifera into Vitis vinifera

 

Vitis Vinifera has been changed to Vitis vinifera throughout the manuscript.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

General comment

The manuscript ''Changes on grape aroma composition as a consequence of foliar application of methyl jasmonate and nano-sized particles doped with methyl jasmonate'' study the influence of foliar application of nanoparticles doped with methyl jasmonate  and foliar application of methyl jasmonate on volatile composition of Tempranillo grapes (or more precisely Vitis vinifera L. cv. Tempranillo) determined by SPME-GC-MS. Article is well done and it is worth to be published in Applied Science journal.

Minor comments

Tables 1 and 2

There is a space before and after symbol ± in Table 1. On the other hand, in Table 2 there is no space before and after symbol ±. Please, use the same way of presentation, not both.

Table 4

Column title Interaction (T × S) should be in one row

References

Line 446: change Vitis Vinifera L into Vitis vinifera L. (Vinifera should begin with lowercase; L should be in Normal and with doth)

Line 484: change Vitis Vinifera into Vitis vinifera (change Normal into Italic; Vinifera should begin with lowercase)

Line 540: change Vitis Vinifera into Vitis vinifera (change Normal into Italic; Vinifera should begin with lowercase)

 

Author Response

MANUSCRIPT applsci-2174316

 

RESPONSE TO REVIEWER 2 AND CHANGES WE HAVE MADE TO THE MANUSCRIPT

 

Firstly, please accept our thanks for the comments you have made on our paper. Your suggestions have helped to improve the quality of the paper. We hope that the answers outlined below and the changes we have made to the text will be satisfactory.

 

The manuscript ''Changes on grape aroma composition as a consequence of foliar application of methyl jasmonate and nano-sized particles doped with methyl jasmonate'' study the influence of foliar application of nanoparticles doped with methyl jasmonate  and foliar application of methyl jasmonate on volatile composition of Tempranillo grapes (or more precisely Vitis vinifera L. cv. Tempranillo) determined by SPME-GC-MS. Article is well done and it is worth to be published in Applied Science journal

 

We thank the reviewer for his/her positive comments.

 

Minor comments

Tables 1 and 2

There is a space before and after symbol ± in Table 1. On the other hand, in Table 2 there is no space before and after symbol ±. Please, use the same way of presentation, not both.

 

We agree with the reviewer's suggestion, and appreciate the correction. Spaces have been added before and after the ± in Table 2.

 

Table 4

Column title Interaction (T × S) should be in one row

 

Table 4: This column has been expanded.

 

References

Line 446: change Vitis Vinifera L into Vitis vinifera L. (Vinifera should begin with lowercase; L should be in Normal and with doth)

 

Line 445: the change has been made.

 

Line 484: change Vitis Vinifera into Vitis vinifera (change Normal into Italic; Vinifera should begin with lowercase)

 

Line 484: the change has been made.

 

Line 540: change Vitis Vinifera into Vitis vinifera (change Normal into Italic; Vinifera should begin with lowercase)

 

Line 540: the change has been made.

Author Response File: Author Response.docx