Involvement of Organic Acid in the Control Mechanism of ε-Poly-L-lysine (ε-PL) on Blue Mold Caused by Penicillium expansum in Apple Fruits
Round 1
Reviewer 1 Report
The authors should follow the following guideline to improve this manuscript.
- Please mention the pH value in the abstract. If possible add significant numerical value/inhibition rate in the abstract.
- What is the significant of this experiment of storage at 25 °C for 9 days? Please write in the Introduction. It is usually normal/standard/room temperature.
- Make space between number and degree centigrade symbol. For example, 25 °C. And follow the entire manuscript.
- Line 186, Page 4: p < 0.05: Is it < Or ≤ ? Confirm this symbol in the entire manuscript.
- Line 190, Page 4: In vitro: Is it ‘In vitro’ Or In vitro? Confirm this style italic/non italic in the entire manuscript.
- Figure 1B: SD lower bar not visible. Please change the color of all bars. And follow the entire manuscript.
- Line 203, Page 5: In vivo: Is it ‘In vivo’ Or In vivo? Confirm this style italic/non italic in the entire manuscript.
- Line 222, page 6: expansum: Make it italic.
- In table 1 mention the significant symbol in superscript.
- Conclusions should write with the best findings.
- If possible reduce references.
Author Response
Response to Reviewer 1 Comments:
Point 1: Please mention the pH value in the abstract. If possible add significant numerical value/inhibition rate in the abstract.
Response 1: Thanks for your advice, we have added pH value and inhibition rate in abstract.
Point 2: What is the significant of this experiment of storage at 25 °C for 9 days? Please write in the Introduction. It is usually normal/standard/room temperature.
Response 2: Sorry, it's our mistake. In that experiment, apples were stored at room temperature for 9 days, and the temperature we measured at that time was about 25 ℃. In addition, we changed the wrong 25 ℃ (line 215) in vivo experiment to RT in the revision.
Point 3: Make space between number and degree centigrade symbol. For example, 25 °C. And follow the entire manuscript.
Response 3: Sorry, it’s our mistake, we have added space between number and degree centigrade symbol (line 121 and line 128).
Point 4: Line 186, Page 4: p < 0.05: Is it < Or ≤ ? Confirm this symbol in the entire manuscript.
Response 4: Thank you for your suggestion. We have reviewed the relevant literature and confirm with the symbol＜in the entire manuscript.
Point 5: Line 190, Page 4: In vitro: Is it ‘In vitro’ Or In vitro? Confirm this style italic/non italic in the entire manuscript.
Response 5: Thanks for your suggestion, we have checked the style of in vitro (line 187 and line 218) and we change all of them to italics in the revision.
Point 6: Figure 1B: SD lower bar not visible. Please change the color of all bars. And follow the entire manuscript.
Response 6: In order to see the SD lower bar in the column chart more clearly, we have changed the color of it in Figure 1B, and we also corrected the other figures.
Point 7: Line 203, Page 5: In vivo: Is it ‘In vivo’ Or In vivo? Confirm this style italic/non italic in the entire manuscript.
Response 7: Thanks for your suggestion, we have checked the style of in vitro(line 200 and line 269), and we change all of them to italics in the revision.
Point 8: Line 222, page 6: expansum: Make it italic.
Response 8: Thank you for this advice. The “expansum” has been revised as “expansum”in revised manuscript.
Point 9: In table 1 mention the significant symbol in superscript.
Response 9: Sorry, it is our mistake, we have marked the significant difference symbol in table 1.
Point 10: Conclusions should write with the best findings.
Response 10: Thank you for your suggestion. Some sentences in the conclusion has been deleted to present the best findings.
Point 11: If possible reduce references.
Response 11:Yes, we deleted some references in the revised manuscript.
Author Response File: 
Author Response.doc
Reviewer 2 Report
The authors in the present study entitled "Involvement of organic acid in control mechanism of ε-poly-L-lysine (ε-PL) on blue mold caused by Penicillium expansum in apple fruit" have addressed to explore the effect of ε-poly-L-lysine (ε-PL) on the pathogenicity of P. expansum, and expound the potential mechanism from the perspective of organic acid. The results showed that ε-PL inhibited the pathogenicity of P. expansum by affecting the accumulation of gluconic acid and slowing the decline of pH in fruit tissue, to affect the pathogenicity of P. expansum. This research will provide new insights into the mechanism by which ε-PL inhibits the growth and infection of P. expansum.
In relation to the methodology, the material and methods content is clear and well redacted. The methodology has been properly applied to approach the proposed objectives.
Specific comments of the methodology:
-Indicate the experimental design of some experiments (ex. 2.4, 2.7, .28), indicating the number petri dishes for each ε-PL concentration or the samples processed or used in each case.
-Point 2.3 is not relevant and information could be included in the corresponding assays, 2.4, 2.5 and 2.6.
About the results, material presented is clear and helps in their comprehension. However, I have some specific comments:
-3.1.2. In vivo test: The efficacy was limited under this conditions and the fact that a reference product was not incorporated into the trial limits the conclusions that can be drawn from the trial.
- Fix typing errors, for example line 247 (“changetest”), line 331 (“acidt”)
About the discussion, it is well documented and the results correctly discussed, just some comments:
-Line 398: Probably there is another reason to take into account, the degradation
-Fix typing error: line 450 (“measuredH”).
The conclusions presented are correctly correlated with the results obtained and derived from the discussion.
Author Response
Response to Reviewer 2 Comments:
Point 1: Indicate the experimental design of some experiments (ex. 2.4, 2.7, .28), indicating the number petri dishes for each ε-PL concentration or the samples processed or used in each case.
Response1: Thanks for your suggestion. In order to make it clear, we have supplemented the relevant contents in Point 2.4, Point 2.7, and Point 28.
Point 2: Point 2.3 is not relevant and information could be included in the corresponding assays, 2.4, 2.5 and 2.6.
Response 2: To make it clear, we deleted the content of Point 2.3 and supplemented the relevant content of 2.4, 2.5 and 2.6.
Point 3: 3.1.2. In vivo test: The efficacy was limited under this conditions and the fact that a reference product was not incorporated into the trial limits the conclusions that can be drawn from the trial.
Response 3: Thanks for your valuable comment. In this experiment, we reported that the effect of ε-PL treatment on blue mold in apple fruit comparing with the control group (the concentration of ε-PL was 0 mg/L). The result showed that when the concentration of ε-PL reached 1000 mg/L or 2000 mg/L, the infection of P. expansum in fruits could be effectively inhibited. We consulted many literatures, Dou et al. explored the effect of ε-PL on apple blue mold[1], and zhang et al. explored the effect of trans-2-hexenal/ β-cyclodextrin on green mold in citrus fruit[2]. They all set up control groups and different concentration groups of drugs to explore the efficacy of target drugs on diseases. Your suggestions are very meaningful, we will improve the rationality of the experimental design in the process. We will pay attention to this problem in future experiments.
Point 4: Fix typing errors, for example line 247 (“changetest”), line 331 (“acidt”).
Response: Sorry, it is our mistake, we have revised “changetest” and “acidt” as “change” (line 247) and “acid” (line 331), respectively. And we checked throughout the MS.
Point 5: Line 398: Probably there is another reason to take into account, the degradation.
Response: Thanks for your valuable comment. We added relevant content in line 398.
Point 6: Fix typing error: line 450 (“measuredH”).
Response: Sorry, it is our mistake, “measuredH” has been revised as “measured” in line 450.
References
[1] Dou, Y.; Routledge, M.N.; Gong, Y.Y.; Godana, E.A.; Dhanasekaran, S.; Yang, Q.Y.; Zhang, X.Y.; Zhang, H.Y. Efficacy of epsilon-poly-L-lysine inhibition of postharvest blue mold in apples and potential mechanisms. Postharvest Biol Tec, 2021, 171, 111346.
[2] Zhang, Y.H.; OuYang, Q.L.; Duan, B.; Reymick, O.O.; Chen, Y.; Tan, Y.Z.; Zhu, X.R.; Su, D.L.; Li, G.Y.; Tao, N.G. Trans-2-hexenal/β-cyclodextrin effectively reduces green mold in citrus fruit, Posthavest Biol Tec, 2022, 187, 111871.
Author Response File: Author Response.doc
Round 2
Reviewer 1 Report
Accept in present form
Author Response
Thank you for your comments.
