Saliva of Therioaphis trifolii (Drepanosiphidae) Activates the SA Plant Hormone Pathway, Inhibits the JA Plant Hormone Pathway, and Improves Aphid Survival Rate

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Summary

The authors presented a thorough evaluation of the impact of Therioaphis trifolii saliva on the modulation of salicylic acid (SA) and jasmonic acid (JA) biosynthesis in plants. The manuscript is recommended for acceptance after a few revisions. References should adhere to MDPI’s style, with a space before square brackets. Minor English editing is highly recommended. Several sentences should be split improving their flow and readability.

Title

Ensure the title aligns with MDPI's guidelines by capitalizing each relevant word.

Abstract

The abstract should be more concise (approximately 300 words).

• Lines 12-14: I recommend splitting this sentence into two for improved clarity on the trial's background.

Introduction

• Lines 101-119: Consider beginning this section by briefly describing the purpose and aim of your study, without including results. Condense these sentences into a four-line paragraph introducing the research context and objective.

Materials and Methods

• Subsection 2.1: Rename this subsection to "Plant Material" for clarity.
• Line 123: Clarify your selection criteria for the genotypes included in the study. For example, specify whether these genotypes were chosen based on specific attributes related to your research.
• Line 135: Along with days, add the plant's phenological phase (e.g., "second true pair of leaves") or provide a growth metric, such as plant height, to contextualize plant development at this point.
• Line 176: A table summarizing the experimental treatments would improve clarity, making it easier for readers to follow the methodology.
• Line 187: The formula should be cited with a reference and placed on a new line for readability.
• Images: Consider including images of the inoculation process and aphid cultures. These visuals, along with a graphical abstract, could enhance comprehension and aid in promoting your work.
• Line 310: Specify the source of the plant material used in analyses (e.g., fresh or dried leaf material).
• Line 334: Clarify "synthetic genes." If you are referring to genes involved in the biosynthetic pathways for SA and JA, specify this to avoid ambiguity.
• Line 352: Indicate the version of "R" used, as well as the specific packages for each statistical analysis.
• Line 356: If you performed a two-way ANOVA, clarify this terminology and describe the model in detail for transparency.

Discussion

The discussion section is well-written and informative. However, I suggest expanding on the following:

-        PAL Gene Involvement: The PAL gene’s role is not limited to SA biosynthesis but also contributes to the formation of lignin and flavonoids. Discuss how PAL activity may increase in response to aphid infestation, potentially enhancing lignin production or the release of insecticidal volatile compounds as a defense mechanism. This addition would strengthen the biological context and implications of your findings.

Comments on the Quality of English Language

The authors presented a thorough evaluation of the impact of Therioaphis trifolii saliva on the modulation of salicylic acid (SA) and jasmonic acid (JA) biosynthesis in plants. The manuscript is recommended for acceptance after a few revisions. References should adhere to MDPI’s style, with a space before square brackets. Minor English editing is highly recommended. Several sentences should be split improving their flow and readability.

Author Response

Dear teacher

I would like to express my gratitude for the teacher's evaluation and recommendations regarding this article.

I have addressed each suggestion and have also engaged with additional literature to enhance the content of the manuscript. Notably, I have included a schematic diagram illustrating the experimental procedures in the section discussing aphid feeding preferences. I am especially appreciative of the teacher's insights concerning the PAL gene, which have inspired further avenues for my future research. This is indeed a topic worthy of consideration. I kindly request that you review the revised manuscript at your convenience.

Should you have any inquiries, please do not hesitate to reach out to me. Thank you once again for your assistance.

2024.11.12

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The authors conducted research on Therioaphis trifolii, an aphid pest affecting Medicago sativa (alfalfa). T. trifolii populations were maintained over 50 generations on two distinct alfalfa cultivars: one susceptible and one resistant to aphid infestation.

 

This study explores how resistant and susceptible aphid strains respond to alfalfa cultivars differing in resistance traits, with a particular focus on how aphid saliva might modulate plant defense pathways. Saliva from T. trifolii reared on the resistant cultivar (referred to as R-saliva) appeared to reduce repellency and toxicity towards subsequent aphid populations feeding on treated plants. In contrast to treatments involving susceptible aphid strains (S-aphids), the resistant strains (R-aphids) induced salicylic acid (SA) pathway activation while simultaneously inhibiting the jasmonic acid (JA) pathway.

 

This hormonal modulation potentially enhances the plant’s suitability for aphid colonization, suggesting that R-aphids may use their saliva to influence the SA pathway, subsequently downregulating JA synthesis. Such interactions may diminish the plant's defensive response, thereby improving aphid survival and colonization.

 

These insights contribute to understanding the mechanisms by which T. trifolii interacts with host plant defenses.

 

Suggestions:

 

The introduction should be more concise and avoid direct references to specific results.

Include annealing temperatures and author citations in Table 1.

Author Response

Dear teacher

I appreciate your feedback on this article, esteemed instructor. I have incorporated the annealing temperatures of the primers utilized in this experiment into Table 1 and have also included citations from pertinent gene sequence databases within the manuscript. The primers were designed independently by us using DNAman software.

2024.11.12

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Authors thoroughly addressed all the comments.