Effect of Sodium Selenite Concentration and Culture Time on Extracellular and Intracellular Metabolite Profiles of Epichloë sp. Isolated from Festuca sinensis in Liquid Culture

Round 1

Reviewer 1 Report

Comments on: ”  Effect of sodium selenite concentration and culture time on extracellular and intracellular metabolite profiles of Epichloë sp. isolated from Festuca sinensis in liquid culture”

The title reflect the content of the manuscript and convey to the readers the scope, design, and goal of the research concerning the relationship between Epichloë sinensis and its host plant, F.sinensis.

Even though there are many other studies on the subject, the Festuca sinensis relationship with Epichlo sp. research is interesting and relevant because it adds to our understanding of the relationship between the grass and fungal endophytes under Se exposure.

The text, which contains a lot of information, is clear and easy to read.

The abstract includes is well organized and it’s a summary of the paper, with background, purpose, short methods, results, and conclusion of the paper.

The introduction provides a good, generalized background of the topic concerning the extracellular and intracellular metabolic changes that occurred in Epichlo sinensis when subjected to different Se concentrations, giving the reader an appreciation of the metabolic mechanisms by which endophytes metabolise Se, the mechanisms of Se-tolerance, and their relationship to their host plants. The introduction is quite substantial and provides 33 references. The last paragraph of the introduction section clearly explains the motivation for the research.

In the methods section are clearly presented the material Epichloë sinensis strain, and methods for the fungal cultivation, the metabolite extraction and derivatization, and briefly the Gas chromatography (GC) coupled to time-of-flight mass spectrometry (TOF-MS) which offers unique solutions for analytical applications. The methods used are appropriate to the aims of the study. Although the authors should probably provide more information about material used in the research, there is sufficient information provided for a other researcher to reproduce the experiments described. I don’t think any additional experiments are necessary to validate the results presented in the manuscript.

Appropriate statistical methods were used to test the significance of the results.

The findings are clearly explained and presented in an appropriate format, with figures and tables displaying important data. The authors used a heatmap and hierarchical clustering to analyse a large amount of data (hundreds of metabolites) using Multiple Experiment Viewer (MeV) software. The data are not duplicated in the graphics and/or text.

Except for the heatmaps and hierarchical cluster analysis, which require more attention to identify the different metabolites, the tables and figures are simple to understand.

I don't believe any additional tables or graphics are required; however, as I previously stated, the heatmaps take time to be read and interpret.

The findings properly described in the context of the published literature (18 references).

The conclusions of the study are supported by appropriate evidence.

The literature cited is relevant to the study, and the authors make assertions substantiating them with references.

The research team has a lot of expertise in this topic and the manuscript is very well organized and well written. The same research was conducted in solid culture (Efect of Sodium Selenite on the Metabolite Profle of Epichloë sp. Mycelia from Festuca sinensis in Solid Culture) and was already published in  Biol Trace Elem Res. . 2022 Jan 1.  doi: 10.1007/s12011-021-03054-w.  However, I did not find any evidence of plagiarism.

I think the paper could prove to be very interesting and useful to a very large audience, possibly making it acceptable for publication in Agriculture Journal.

My recommendation is for minor revision.

See the comments on manuscript

Comments for author File: Comments.pdf

Author Response

Point 1: The title reflect the content of the manuscript and convey to the readers the scope, design, and goal of the research concerning the relationship between Epichloë sinensis and its host plant, F.sinensis.

Even though there are many other studies on the subject, the Festuca sinensis relationship with Epichloë sp. research is interesting and relevant because it adds to our understanding of the relationship between the grass and fungal endophytes under Se exposure.

The text, which contains a lot of information, is clear and easy to read.

The abstract includes is well organized and it’s a summary of the paper, with background, purpose, short methods, results, and conclusion of the paper.

The introduction provides a good, generalized background of the topic concerning the extracellular and intracellular metabolic changes that occurred in Epichlo sinensis when subjected to different Se concentrations, giving the reader an appreciation of the metabolic mechanisms by which endophytes metabolise Se, the mechanisms of Se-tolerance, and their relationship to their host plants. The introduction is quite substantial and provides 33 references. The last paragraph of the introduction section clearly explains the motivation for the research.

In the methods section are clearly presented the material Epichloë sinensis strain, and methods for the fungal cultivation, the metabolite extraction and derivatization, and briefly the Gas chromatography (GC) coupled to time-of-flight mass spectrometry (TOF-MS) which offers unique solutions for analytical applications. The methods used are appropriate to the aims of the study. Although the authors should probably provide more information about material used in the research, there is sufficient information provided for a other researcher to reproduce the experiments described. I don’t think any additional experiments are necessary to validate the results presented in the manuscript.

Appropriate statistical methods were used to test the significance of the results.

The findings are clearly explained and presented in an appropriate format, with figures and tables displaying important data. The authors used a heatmap and hierarchical clustering to analyse a large amount of data (hundreds of metabolites) using Multiple Experiment Viewer (MeV) software. The data are not duplicated in the graphics and/or text.

Except for the heatmaps and hierarchical cluster analysis, which require more attention to identify the different metabolites, the tables and figures are simple to understand.

I don't believe any additional tables or graphics are required; however, as I previously stated, the heatmaps take time to be read and interpret.

The findings properly described in the context of the published literature (18 references).

The conclusions of the study are supported by appropriate evidence.

The literature cited is relevant to the study, and the authors make assertions substantiating them with references.

The research team has a lot of expertise in this topic and the manuscript is very well organized and well written. The same research was conducted in solid culture (Effect of Sodium Selenite on the Metabolite Profile of Epichloë sp. Mycelia from Festuca sinensis in Solid Culture) and was already published in  Biol Trace Elem Res. . 2022 Jan 1.  doi: 10.1007/s12011-021-03054-w.  However, I did not find any evidence of plagiarism.

I think the paper could prove to be very interesting and useful to a very large audience, possibly making it acceptable for publication in Agriculture Journal.

My recommendation is for minor revision.

Our response 1: We appreciate your comments which are very usefully for improving our paper. We have revised the whole manuscript carefully. 

 

Reviewer 2 Report

Hi 

Well presented with the available data. It will be good if the unique outcome is highlighted. With any stress given the metabolites will change in response the stress level. So highlighting the metabolite responses as as major outcome seems to be beating around the bush. The result can be discussed with specific objective to solve some real world problem or throwing light on understanding something in Epichloë sp. 

Minor corrections are in Line 15 "weeks 4 to 8 of cultivation" can be changed to 4 to 8 weeks of cultivation. line 497 and 498 "be due to" repeated. Also, weight and volume measurement are given with standard error (100±1) which is not appropriate. Standard error was given when randomness is involved in the observation which cannot be controlled by the observer.

All the best

Thank you

Author Response

Point 1: Well presented with the available data. It will be good if the unique outcome is highlighted. With any stress given the metabolites will change in response the stress level. So highlighting the metabolite responses as as major outcome seems to be beating around the bush. The result can be discussed with specific objective to solve some real world problem or throwing light on understanding something in Epichloë sp. 

Our response 1: We appreciate this reviewer’s thoughtful comments. We have tried to improve the discussion section.

Point 2: Minor corrections are in Line 15 "weeks 4 to 8 of cultivation" can be changed to 4 to 8 weeks of cultivation. line 497 and 498 "be due to" repeated. Also, weight and volume measurement are given with standard error (100±1) which is not appropriate. Standard error was given when randomness is involved in the observation which cannot be controlled by the observer.

Our response 2: We have revised them according to the comments.