Effects of Bacillus subtilis on Rose Growth Promotion and Rhizosphere Microbial Community Changes under Saline–Alkaline Stress
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript entitled" Effects of Bacillus subtilis on rose growth promotion and rhizosphere microbial community changes under saline-alkaline stress" is a nice attempt to study various PGPR and other effects on rose plant physiology and growth. The whole study and manuscript is well structured and organized. But there few points that needs to be addressed like parameters like Soil variables and Variation in soil pH, organic C (%), mineral-N (μg N g-1), K2O (kg hec-1), S, Zn, Fe and Mn have been studied or not.
As the study has been conducted in two parts 1. Effect of Bacillus subtilis on rose growth promotion and 2. Change in rhizosphere microbial community under saline-alkaline stress. It is important to discuss the effect of Bacillus subtilis on the rhizosphere microbial community in detail.
The captions inside the graphs of figure 2 are small, size needs to be increased.
One photograph comparing control with Bacillus subtilis supplementation on plants at (flowering stage/appropriate stage) can be included in the manuscript.
Author Response
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Author Response File: 
Author Response.docx
Reviewer 2 Report
Comments and Suggestions for AuthorsThe study showed effects of Bacillus subtilis on plant growth promotion and the rhizosphere microbial community in the rose growth environment under saline-alkaline stress. For Saline-alkaline stress Bacillus subtilis was used to observe its impact on roses.
The manuscript needs revisions as highlighted in the manuscript file,
There should be ANOVA results to show the significance of results for studied traits.
Comments for author File: 
Comments.pdf
Needs improvements
Author Response
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Author Response File: Author Response.docx
Reviewer 3 Report
Comments and Suggestions for AuthorsDear Authors,
In my opinion, the manuscript addresses the important and topical issue of using microorganisms in promoting plant growth and improving soil quality. As the authors put it in the introduction, saline-alkaline stress is an increasingly serious problem in agronomy, and it is right to look for opportunities to reduce its negative effects on plants.
Introduction
In my opinion, the introduction provides a good introduction to the issues addressed in the research part of the manuscript. It adequately and sufficiently discusses the problem of soil salinity and its effects on plants. Subsequently, it sufficiently discusses the impact of PGPR on the issue being addressed. The purpose of conducting the experiment is also correctly stated.
Materials and methods
Overall the section is fairly well structured however I have a few minor suggestions. I did not find a funding and conflict of interest statement in the manuscript, I mention this because of the mention of company names in this section. If possible, I would suggest avoiding the specific names of the companies providing the particular materials used in the study and only stating the composition (as was recorded for the soil substrate) with the notation that it was a commercial material.
In addition, in this section I found no information on how many replicates the experiment was carried out in. The statistical methods used to analyze the data were also not described. I would suggest supplementing this information.
Results
The section in my opinion is adequately structured and clearly presents the results obtained. A minor suggestion is to move: "a finding that could be attributed to the increased salinity in the soil, where lower salinity conditions accelerated nitrification rates, and higher salinity conditions reduced them [28]." To the discussion section.
Discussion
The section is fairly well structured, however, I would suggest more supplementation with reference to similar research conducted by other Authors and suggesting mechanisms for the effects of the various management techniques tested on the traits analyzed.
Conclusions
The section is properly constructed I have no suggestions for it.
References
I suggest working on this section. I suggest standardizing because there are many forms of citation.
Good luck
Author Response
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Author Response File: Author Response.docx
Reviewer 4 Report
Comments and Suggestions for AuthorsI think the topic is interesting, but I have some concerning:
Abstract:
- Too exhaustive. Really needs a resume effort, and include only the key concepts and relevant results
- Include context to reference the relevance of this study
Introduction:
- It's a good introduction, but the topics should be more focused, each addressed item seems like a decontextualized exploration of the topic. For example, talking about PGPR you express very general concepts instead of focus in their relevance for saline-alkali conditions. These practices disperse from the main topic
Materials and Methods:
- The sections are too short and, despite some has sense to be, for others is necessary to explain more and better to enhance the resolution and reproducibility
- Scientific names of species goes in italic
- 37ºC seems high for B. subtillis incubation
- LB medium composition? Or citation.
- 'Culture medium' is not a correct title. Consider 'Soil composition' or 'Soil mix'. These kinds of short topics should be joined to avoid dispersion
- B. subtillis growing in liquid nutrient broth medium (composition?) for 72 h get exhausted and old and sporulating population.
- Adjust CFU to 108? Get the numbers doesn't mean anything without a context. Are they sporulated cells? Fresh cells? Did you check the growth curve of the strain?
- Some methodologies require more detail in order to ensure reproducibility (as POD, CAT or MDA activity). This happens continuously
- Some sections overlap and cause reiterations, consider to join them
Results:
- Too exhaustive as well, but at least in this section could be reasonable. Support more in the figures and tables, so don't need to reflex each result in the text but the main relevant ones
- For box plots, consider other outline color to favor the interpretation
- Many parameters under salt-alkali conditions are not significative, correct this in the text, can lead to many misunderstandings
- Again, scientific names of the species goes in italic
- In section 3.2 too many contradictions in the assessments, and with the figure results interpretation...
- In most of the cases, the effect of the strain with no stress is reducing enzymatic activities, but they augment under stress conditions. This is overall should be compared with the phenotype to discern the involved traits
- Metabolically, the changes are minimal, please consider at the time to elucidate why
- No any picture of the treatments? Phenotypical validation requires some visual support...
Discussion:
- The positive effect of the strain is not that evident, so I would suggest to mild your words and contextualize by parameter
- I think the evaluation of results is too optimistic...
Conclusions:
- Again, careful with the assessments, they are not solidly based
- By only metagenomics and functional metagenomics, without an experimental assessing, you cannot say the strain treatment enhances the presence of beneficial bacteria. In the best of the cases, putatively it does it. In the same increased genus under treatment you can find even pathogens, so imagine how solid is this...
Author Response
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Author Response File: Author Response.docx
Round 2
Reviewer 4 Report
Comments and Suggestions for AuthorsThanks for taking into the account my suggestions. I still see very report-like the results section, but I'm going to leave the decision to the editor.
