Early Diagnosis of Pine Wood Nematode Disease Based on Chlorophyll Fluorescence Parameters and Organic Acids

Round 1

Reviewer 1 Report

Dear Author,

Thank you for your this valuable submission. Generally your paper is well designed and scope of journal. However, I have some minor comments before accepted this paper. 

Specific comments: 

1- Please support these below sentences with properly references

"Chlorophyll molecules of plants absorb light quantums to excite  electrons from the ground state to the excited state and then return to the ground state in  different ways, such as photochemical reactions, fluorescence scattering and heat dissipation"

Toxins are considered an important group of pathogenic factors in pine nematode  disease.

This may suggest that pine nematode invasion can induce the  production of phytotoxins in pine trees to defend against them but that excessive accu- mulation of toxins can also cause damage to the tree's own cellular tissues. The metabolic  pathway of toxin production in pine trees may be an important pathway for pine resistance, but it is still unclear which toxin plays the dominant role in the pathogenesis of  PWD and the mechanisms involved. In-depth study of toxins is therefore of great im- 92 portance for the control of pine nematodes. 

2- Please extend research backround literatures. 

3- Even the methods explained well, the data analysis part is needed to extend with briefly and add more information about your statistical analayses. 

4- Please add some statistical lettering for table 1 for better understanding. 

5- Please rephrase conclusion of paper. It seems like results part. 

Best regards

 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Early diagnosis of any plant pest or pathogen is crucial for protection measures undertaken before the harmful effect or disease affect the whole plant. The analysis of signals emitted from chlorophyll "a" fluorescence and measure of organic compound level have become powerful tools in monitoring plant responses to various environmental factors affecting forest tree species. The paper is part of the trend of early plant diagnostics based on two-track analyzes of photosynthetic activity at the level of the PSII photosystem (including measurements of the initial fluorescence Fo, the index Fv/Fm of the maximum photochemical efficiency of photosystem II, or the efficiency of various reaction centers expressed on the basis of ABS/RC, TRO/RC, and DIO/RC, etc. The non-photochemical quenching parameters, like Qp_L1, Qp_L2, QY_L1, QY_L2, and QY_ Lss, were also included in the study of the pine reaction to the nematode (Bursaphelenchus xylophilus) attack. The measure of chosen organic acid content in pine needles, as secondary metabolites (e.g. ferulic acid or jasmonic acid) produced by stressed plants, may largely help to evaluate the early stage of nematode attack. Interesting would be a study of the hsp genes expression in pine needle cells, to complete the study of alert levels in infected plants.

The article is well-constructed and clearly presented. The experimental design was properly presented and the results were statistically proven.

I would only remove the china letters from graphs in Figure 3 (Y axis), which is put, by the way, two times in the text (on pages 6 and 7).

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

Major comment.

The manuscript is well-written, and it's clear that the authors collected a large amount of data. However, in its current form, the manuscript is lacking a proper analysis. The authors only used ANOVA test, which does not align with the research objectives.

 

Minor comments : 

L 14- 16 : Please refrain from using acronyms in the abstract. The authors have requested that the full name of each component be added instead.

 

L28-31: The paragraph about pine wood nematode appears to be insufficiently detailed. The authors should consider incorporating additional information about this disease to provide a more comprehensive explanation. For instance, they could delve into the life cycle and characteristics of the pine wood nematode, elucidate the symptoms it causes in infected pine trees, and explore the potential economic and environmental impacts of its spread. Additionally, including information on current methods of detection, prevention, and control would further enhance the understanding of this significant issue. By providing a more in-depth analysis, readers will gain a thorough grasp of the pine wood nematode and its implications, contributing to a richer and more valuable study.

The transition between paragraph one and two in the introduction section is lacking, as the authors immediately delve into the topic of photosynthesis without establishing a clear connection with the preceding paragraph

The rest of the introduction section is well written .

Data Analysis:

In my opinion, the data analysis section appears to be somewhat limited in depth and complexity. The authors have solely relied on the use of the ANOVA test, while there exists a plethora of other statistical approaches that could be employed to comprehensively evaluate the temporal changes of the studied variables. By incorporating a broader range of statistical methods, the study's findings could be more robust and nuanced, providing a deeper understanding of the observed trends over time. Therefore, I suggest that the authors consider exploring and incorporating additional statistical techniques that align with the research objectives, allowing for a more comprehensive and insightful analysis of the data.

L175: what is 17d? correct.

The authors asked to improve the quality of Figures 1,2 and 3. In its current state, it is difficult to understand and read its contents.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

I thank the authors for their responses, and I am satisfied with the changes