Contact Mechanics between Torus and Pit Border for Developing Air-Seeding Seal in Aspirated Bordered Pits

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Nice work. I really enjoy reading this manuscript. The experimental design was reasonable, and the methods used were the standard ones. I strongly recommend Accept this nice article after response to my next minor comments.

1.     Hypothesis of study should be elaborated in more detail.

2.     Use scientific language and significant editing of language is also recommended

3.     References and must be updated

4.     Introduction need to improve with mor information

5.     Materials and Methods and results good written and clear statement

6.     Discussion need to improve with mor information

Comments on the Quality of English Language

Moderate editing of English language required

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript by Peng et al. describes mechanical model of displacement of the torus-margo complex under pressure. This work seems to be interesting. However, I have some comments.

(1)  Most of relationships in figures are weak (correlation coefficients are low). Please, discuss this point.

(2)  Please, to add in Figure 1 and 3 names of elements.

(3)  The numeration of figures should be corrected, the manuscript content two “Figure 5” (see P. 5-6).

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript present a interesting topic and new findings about functions on pit in conifers. The quality of presentation, originality and scientific soundness are excellent.

I have only two questions and suggestions:

1. Line 125. What is Fixative B? I suggest include chemical/ solution formula

2. According to Maschek et al (2013, ref 14, line 302), immunocytochemical analyses were made in Pinus in order to verify the composition of the torus and margo. Although Platicladus orientalis is a conifer like Pinus, I wondering if the composition of pit would be the same of Pinus as commented in the Discussion (lines 302 to 307). Thus, I do not know if you could make the same association about the chemical composition of the torus and margo in P. orientalis. I suggest to rewrite this paragraph in order be clearer.

Author Response

Dear Editors and Reviewers:

Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Contact mechanics between torus and pit border for developing air-seeding seal in aspirated bordered pits” (ID: forests-2650359). Those comments are all valuable and very helpful for revising and improving our paper and the important guiding significance to our research. We have studied comments carefully and have made a correction which we hope meet with approval. Revised portions are marked in red on the paper.

The main corrections in the paper and the response to the reviewer’s comments are as follows:

 

Comment #1: Line 125. What is Fixative B? I suggest include chemical/ solution formula.

Response: The chemical solution is 1% osmic anhydride and is replaced with Fixative B in the manuscript.

 

Comment #2: According to Maschek et al (2013, ref 14, line 302), immunocytochemical analyses were made in Pinus in order to verify the composition of the torus and margo. Although Platicladus orientalis is a conifer like Pinus, I wondering if the composition of pit would be the same of Pinus as commented in the Discussion (lines 302 to 307). Thus, I do not know if you could make the same association about the chemical composition of the torus and margo in P. orientalis. I suggest to rewrite this paragraph in order be clearer.

Response: Due to the absence of immunocytochemical analyses, we cannot confirm whether the chemical composition of the torus and margo in P. orientalis is identical to that of Pinus. Many studies have identified the sandwich structure of the torus since the 1960s in the last century. Based on the presupposition that the pectin material empirically is softer than the cellulose material, the advantage of the torus sandwich structure is discussed as following

“The torus in Pinus strobus L. observed using 4Pi and confocal laser scanning microscopy was a sandwich structure more complicated than the torus structure modeled in the present study, in which the dense and nonporous pectin layer on the surface encircled the inside cellulose layer[14]. Although there may be differences in chemical composition and microstructure for the cellulose layer and the pectin layer across species, the presence of a sandwich structure has been consistently observed across several species[40,41]. Based on the empirical hypothesis that the pectin material was significantly softer than the cellulose material, it was advantageous for the torus sandwich structure that the inner cellulose layer was subject to external pressure load to prevent seal failure due to excessive deformation, while the soft pectin layer was able to fill and seal the roughness on the surface of the pit border under the squeezing forces in the contact area.”

 

Thank you very much for your comments and suggestions.

 

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Authors considered my comments. I have not additional remarks.

Author Response

Thank you very much for your help.