Transcriptome Analysis and VIGS Identification of Key Genes Regulating Citric Acid Metabolism in Citrus

Round 1

Reviewer 1 Report

The review of Chen et al. “Transcriptome analysis and VIGS identification of key genes regulating citric acid metabolism in citrus” deals with transcriptome analysis of two contrasting citrus varieties (low- and high-acid content) at different developmental stages aimed at identification of genes that determine acid content in citrus. Using VIGS, two differentially expressed genes, citrate synthase (CS) and ATP citrate-pro-S-lyase (ACL), were identified as candidate genes regulating citric acid content in citrus fruit. Analysis of genes controlling citric acid content in citrus fruit is important for breeding of early-maturing and low-acid varieties with reduced levels of organic acids after ripening. The manuscript of Chen et al. presents novel data on quality traits and differential gene expression in two citrus varieties that differ in acid content and the role of CS and ACL in citric acid accumulation. However, the manuscript needs revision to be published in CIMB.

My comments are given below.

1.  The Abstract should be revised. It is necessary (1) to mention the contrasting varieties used for analysis; (2) to state more clearly what was done and which main results were obtained. Repetitions should be deleted (lines 13-15 and lines 18-20).

2.      Grammar mistakes should be corrected, such as “The results shown…” (lines 16, 17 and throughout the text), “The citric acid content highest...” (line 49), etc.

3.      References should be added: lines 59-60, lines 76-78, lines 100-101, lines 336-345.

4.      Subtitle 2.2. Unclear “total of soluble sugar titratable acid”.

5.      Section 2.4. The title is “RNA extraction and transcriptome sequencing data comparison”. However there isn’t a word about sequencing data comparison in this paragraph.

6.      Section 2.5. What does it mean “enrich differential expression genes”?

7.      Section 2.10. Lines 163-170 are irrelevant to this section.

8.      Section 3.2. A phrase “A significant difference …” (lines 191-192) should be put before “Figure 2A shows that …” (line 188).

9.      Figs. 1-3. Figure captions must be changed to “Fructose, sucrose… concentration (content) in citrus fruit …” etc. The name of coordinate axes should be specified. The letters “a, b, c, d, e, f” in the Figures should be explained.

10.  Fig. 4. The order of DEG arrangement needs to be changed to facilitate comparisons.

11.  Fig. 5. The font is too small to read.

12.  Fig. 6. “Choose the module with the highest…” What does it mean? The figures on the heat map should be explained.

13.  Fig. 7. “-1*log10” should be explained. Fig. A is not properly cropped.

14.  Fig. 8. It should be explained what columns and graphs mean.

15.  Figs. 9 and 10. The captions are wrong. The electrophoregrams, not “PCR verification of bacterial liquid…” are presented.

Author Response

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Reviewer 2 Report

 "Transcriptome Analysis and VIGS Identification of Key Genes Regulating Citric Acid Metabolism in Citrus" to our journal. After careful review of your work, we have concluded that this study has potential but requires major revisions before it can be considered for publication.

Firstly, it is not clear how the two differentially expressed genes (CS and ACL) were selected from the transcriptome data. Please provide a detailed explanation of your selection criteria and the statistical methods used to identify these genes.

Secondly, we recommend that you provide more information on the VIGS vectors used in the study. Please include details on the design and construction of the vectors, as well as the methods used to deliver them to the citrus plants.

Thirdly, we suggest that you conduct additional experiments to further validate the results of the VIGS experiments. Specifically, we recommend that you include quantitative measurements of citric acid content, as well as additional statistical analyses to confirm the significance of the results.

Finally, we recommend that you provide a more detailed discussion of the implications of your results for the citrus industry. Specifically, we suggest that you discuss the potential impact of your findings on breeding programs aimed at developing low-acid citrus varieties.

Author Response

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Reviewer 3 Report

The paper investigates OA v Sugar accumulations in citric acid fruits of two varieties chosen for their different properties. 

The work is difficult to follow   poor writing    contributes , many many abbreviations       means flipping back and forth    

reference to unpublished work 

poor methods and legends 

 

please add cartoon to show important enzymes and gene regulation  

 

Comments for author File: Comments.pdf

Author Response

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Round 2

Reviewer 3 Report

there is very little evidence of editorial changes 

to become acceptable you need professional help 

Comments for author File: Comments.pdf

Author Response

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