The Genes Associated with Jasmonic Acid and Salicylic Acid Are Induced in Tropical Chili Pepper against Ralstonia solanacearum by Applying Arbuscular Mycorrhizal Fungi

Round 1

Reviewer 1 Report

The study is very interesting and generally well presented. There are, however, aspects that need to be improved, especially regarding the presentation of some results and the wording of some conclusions.

Lines 57-58: There seems to be a phrase with a duplicated idea ("it has also been observed that the SA pathway interacts with beneficial symbionts.").

Lines 78-82: This should be in Conclusions or at the end of Discussion, but not in the Introduction.

Line 87: With the phrase "generative growth phase", do authors mean "vegetative"? I saw later that the measurements were at the start of the generative growth phase. The writing can be clarified, please check.

Line 98: Please check magnitude or units of spore density.

Line 105: Consider to delete the word "ass".

Lines 123: Consider to use "withered" instead of "wilted".

Line 128: Please add "<" before 30%.

Lines 131-134: These two phrases seem to be redundant.

Lines 142: Consider to use "seedling" instead of "sprout".

Line 145: Please check that you really used 1 part of medium to 10 parts of inoculum, and not 10 to 1.

Lines 145-146: It is not clear if the seedlings were maintained 21 days after or before transplanting. Maybe delete the text in line 146 after "...until they were 21 days old."

In section 2.2 it is not clear how the two experiments have a different structure, if they have. If the experiments were performed in the same group of plants (with the same treatments), the text should make it clear. If the experiments were really different, the text should make it also clear. Please state the differences. After reading a second time, it seems to me that there were two sets of plants for the experiments. Ideally, the reader understands this clearly in a first reading. I recommend to follow a chronological sequence to explain the steps performed in each experiment, i.e. seeding, transplanting, inoculating, sampling, measuring, etc. This will allow to better understand the procedures.

Line 205: Maybe there should be a dot at the end?

Line 237: In Figure 1, the abbreviation AMF is not defined.

Line 245-246: Is not clear what does the last phrase mean.

Lines 247-252: This text is a bit redundant, since it describes what is already in Figure 1.

Lines 272-308: Again, this text tends to describe the results exposed in Figure 2 and some other, but I wonder if there is an alternative way of showing these results in a more attractive way, maybe using tables.

Lines 310-322: It may be more informative to show (in Figure 3) the responsiveness and resistance of genotypes, in order to facilitate the reader's understanding. It may be better to highlight (in the text) those situations that are important or have consequences.

Figure 3: The description is long, maybe the authors can show in the graph the responsiveness and susceptibility, perhaps using horizontal color bars under the X axis.

Lines 334-336: This text is not very clear, please reword the phrase.

Lines 334-355: Similar to lines 310-322, please see observations there.

Figures 4 and 5: AMF not defined.

Line 374: Please check that PCA was already defined in the text.

Lines 376-380: Please review if this really correspond to Results or it better suits to Discussion. For the reader, it will possibly be more clarifying if the authors briefly explain why "is a kind of responsiveness variable".

Line 383: Please consider to reword the phrase. I understand that the groups of genotypes are visualized from the application of a certain method (e.g. average heatmap method in R, maybe using a particular package that would be good to mention). The four groups mentioned are not visible in the heatmap. Maybe you can make explicit those groups using colours in the genotype codes at the right of the heatmap.

Lines 387-392: Some phrases may be better placed in the Discussion section. Also, please consider if the use of the expression “was affected by” is properly used. It denotes causality, but I understand that the gene expression and the resistance are related, or correlated, but from the present work it is not clear that the resistance is the cause of a given gene expression.

Figure 6: Please check the abbreviations, CA=PCA?, Dinc=DInc? (for the last, check also previous figures). The black lines on top and at the left (Clusters? Dendrogram?) should be explained.

Lines 412-413: What do you mean by “that the symbiosis was mutualistic”? This statement is rather basic for mycorrhizae and it does not seem to arise from the observations of the study. Please check the idea to be communicated, and the wording.

Lines 426-432: Authors may strength this part of the Discussion arguing that locally adapted germplasm is important for genetic breeding, and giving more information on the origin of germplasm used in Indonesia for crop breeding, and the origin of Capsicum cultivars used in Indonesia.

Lines 445-450: This part of the text does not really belong to Discussion.

Lines 462-467: I think the reasoning is not very clear, and/or the interpretation is not very clear from the results. Ideally, the reader should be able to interpret the same when observing the graphs. Maybe the observations made to Figure 3 (which can be also applied to Figure 2) will help with this.

Lines 468-470: Again, the interpretation stated in the text is not clearly visible from the figures. There seems to be several genotypes where the gene expression of JA does not seem to be higher under infection.

Lines 497-498: This is not clear from Figure 3. There should be some way of grouping the bars from the graphs in order to be able to observe the trends stated in the text.

Lines 500-502: The text is not clear, please reword.

Line 510: “The increase in JA inhibited the SA pathway.” I am not sure if this can be stated so categorically from this study. More likely, in agreement with previous studies, there seems that the responses observed in this study suggest that.

Line 511: “… and increased plant resistance to R. solanacearum”. This is not shown in Results. In order to support this assertion, it would be good to show the comparison of Disease Intensity in plants with and without mycorrhizae inoculation.

Lines 522-523: As far as I can see and understand from Figure 2, there are 5 genotypes where the relative gene expression of JA is lower in M1R1 than in M0R1, so priming may not be present in all cases.

Lines 547-549: According to what is observed in lines 510, 511 and 522-523, this conclusion is not well supported on the results presented. It needs more information, and authors probably have that information.

Lines 549-553: As observed previously, it is not clear the antagonistic relationship from the results of the study. The same with the mycorrhizae inducing gene expression.

Lines 553-556: I fully agree with this wording, “These results suggests that…”

Author Response

Dear Reviewer, 

I extend my gratitude and appreciation to the reviewer who have improved our manuscripts so that our manuscripts become better quality. I had fixed all the revisions. All the improvements we have marked in the manuscript. Once again, we would thank you very much. Good luck, always.

Best Regards Authors

Author Response File: Author Response.pdf

Reviewer 2 Report

This paper discribed that Jasmonic Acid and Salicylic Acid Genes are Induced in Tropical Chili Pepper Against Ralstonia solanacearum By Applying Arbuscular Mycorrhizal Fungi. I think this paper is of great interest to the plant scientific community. However, unfortunately, there are both insignificant and significant remarks, as well as issues that should be taken into account.

Significant remarks

1. Only the expression analyses of two genes associated with JA and SA were conducted in those 10 tropical chili pepper genotypes. Thus, the author described the title as "Jasmonic Acid and Salicylic Acid Genes are Induced in Tropi-2 cal Chili Pepper Against Ralstonia solanacearum By Applying Arbuscular Mycorrhizal Fungi".  What are the roles of these two genes in the JA and SA signal pathway. Why the authers choose these two genes? I think the titile of this paper is big. It could be written as these two genes, but not Jasmonic Acid and Salicylic Acid Genes.

2. Only the gene expression analysis were conducted post innoculation, but no phenotypic analysis. The paper do not show the phenotypic analysis of 10 tropical chili pepper in M0R0, M1R0, M0R1, M1R1. I think the authors need to perform these experiments, which could explain the roles of mycorrhizae on strengthened the immune system.

Insignificant remarks

1. lines 24-25. The leaves of 10-week-old plants were post innoculation? It is confused for readers. Please correct it.

2. Line 58, the "19" after beneficial symbionts is needless, could be remove?

3. Lines 80-82, It should be "....relative gene expression of the JA and SA....", same mistakes in line 87. Please correct it.

4. The reference gene in Table 1 is lack of the reverse primer.

5. Lines 225-226, Please list which four genotypes was high, which four genotypes and two commercial cultivars were low. It could be corrected as "....four genotypes (***) was high; ....four genotypes (***) and the two commecial cultivars (***)..."

6. The references should be corrected as refer to the Horticulturae journal.

Author Response

Dear Reviewer, 

I extend my gratitude and appreciation to the reviewer who have improved our manuscripts so that our manuscripts become better quality. I had fixed all the revisions. All the improvements we have marked in the manuscript. Once again, we would thank you very much. Good luck, always.

Best Regards Authors

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments to the Author

General:

The work addresses socially important issues related to the provision of high plants yields. The pathogen-free substrate - whether in field or tunnel cultivation - is the starting point for plant health.The subject matter of the work is within the scope of the Horticulturae paper, but some things are not fully developed.

Specific comments:

1.     Why was oven-baked at 68 °C for 48 h used during the dry matter test. Are these measuring conditions standardized?

 

 

Author Response

Dear Reviewer, 

I extend my gratitude and appreciation to the reviewer who have improved our manuscripts so that our manuscripts become better quality. I had fixed all the revisions. All the improvements we have marked in the manuscript. Once again, we would thank you very much. Good luck, always.

Best Regards Authors

Author Response File: Author Response.pdf

Reviewer 4 Report

The manuscript presents a relevant and interesting work. However, the research objectives need to be clearly outlined. So I recommend minor revisions.    

Author Response

Dear Reviewer, 

I extend my gratitude and appreciation to the reviewer who have improved our manuscripts so that our manuscripts become better quality. I had fixed all the revisions. All the improvements we have marked in the manuscript. Once again, we would thank you very much. Good luck, always.

Best Regards Authors

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I fully appreciate the effort authors have done to improve the manuscript looking at every comment. I encourage them to keep working with high scientific standars.

Reviewer 2 Report

Thank you for your comments and corrections. I agreed the resubmitted article for publication in the Horticulturae journal.  However, the Figures should be clear in the published paper.

Best regards,

reviewer