Effects of Bacillus subtilis HS5B5 on Maize Seed Germination and Seedling Growth under NaCl Stress Conditions

Round 1

Reviewer 1 Report

Manuscript topic is interesting, current and well presented. References cited in the manuscript are up to date as well. English is well written and easy to follow. 

Material and Method Section needs minor improvements that are suggested in comments in PDF file attached. My major doubt is - are the samples you took for the analyses representative enough for conclusions you've made? As you wrote - five plants per treatment - is not enough for reliable conclusion. You need at least five plants per replicate which would be 15 plants per treatment...otherwise the manuscript does not have satisfying quality required for such high impact journal.

Comments for author File: Comments.pdf

Author Response

请参阅附件。非常感谢。

Author Response File: Author Response.docx

Reviewer 2 Report

The search for new plant growth-regulating microorganisms that increase plant resistance to abiotic stresses is a promising direction, especially for the creation of new highly effective crop yield-increasing preparations. From this point of view, the work of the authors Peng Song, Biao Zhao, Xingxin Sun, Lixiang Li, Zele Wang, Chao Ma and Jun Zhang "Effects of Bacillus Subtilis HS5B5 on Maize Seed Germination and Seedling Growth under NaCl Stress Conditions" is relevant and perspective.

At the same time, in my opinion, its presentation needs to be improved.

Questions and remarks:

2. Materials and methods

2.1.

- Add: the origin of the bacterium, what characteristics it has, why it was chosen for research.

- On what nutrient medium was the strain cultivated to prepare the suspension?

2.3.

Describe in more detail the procedure for treating plants with salt after inoculation with bacterial cells.

2.5.

- How was the height of the plant measured?

“Root to Crown Ratio = G1/G2" should be replaced by "Root to Shoot Weight Ratio (g/g)" because, as the authors write, "G1 represents the below-ground fresh weight" (respectively, this is the Weight of the root) and "G2 represents the above ground fresh weight" (respectively, this is the Weight of the shoot). Replace «(g strain-1)» with «(g)». Make appropriate changes to Fig. 2. and the text of the manuscript.

Fig. 1 and Fig. 4 - on the axis should be "biomass (g) “ and «fresh weight (g)" not «(g strain-1)».

Fig. 4 - specify leaves or shoot in the caption.

2.8.

Explain what is the basis of the methods used, is not just to list them.

Fig. 2-13 - indicate what the letters mean and what is being compared.

Fig. 5 and 13 - correct the figures, since the words on the axes are unreadable.

3. Results

Line 196. Remove the word «gradually»

References

Check if DOI is correct

35. Lastochkina O. Bacillus subtilis-mediated plant tolerance to abiotic stress. Springer, Cham 2019, 97-133. DOI: 10.1007/978-3-030-595 15175-16.

The study is of scientific and practical interest, but the article needs to be finalized, especially pay attention to the presentation of the methodological part.

 

 

 

 

 

Author Response

Please see the attachment. Thank you very much.

Author Response File: Author Response.docx

Reviewer 3 Report

The article is devoted to the problem of elucidating the mechanisms of mitigation of stress caused by salinity due to inoculation with the strain B. subtilis HS5B5. The authors estimated many parameters of morphometric properties under NaCl stress conditions. Statistically treated data and description of methods in details are out of doubt. But for improving the understanding of text it is necessary to make several remarks and questions.

1)     Lines 104-106: «a foam  board containing charcoal soil and vermiculite (1∶1) …was placed in a pot, containing 2 L maize total nutrient solution» It is not understandable how this plant growth system was looked like. It will be good to present the photo.

2)    Line 106: what is «maize total nutrient solution (pH 6.0 ± 0.1)»?

3)    Lines 125-127: «The roots and leaves were placed in an electric blast drying oven at 120 °C  for 15 min. The oven temperature was adjusted to 75 °C and the samples were dried to a constant weight». It is not clear, why the samples were dried, f there wasn’t the information about the parameters of dried plants?

4)    Line 146: The error in abbreviation catalase 145 (POD), and peroxidase (CAT)

5)    Lines 374-376: «We observed that the root-to-crown ratio of maize increased somewhat in response to the NaCl treatment, probably because the salt stress suppressed the growth of the above-ground plant parts more than the growth of the roots». Probably,  there was an an adaptive redistribution of resources in favor of root growth, and not suppression of the growth of the aerial part?

6)    Line 384: What is meant by «cystoid membrane»?

7)    Lines 395-396: This effect of B. subtilis HS5B5 may involve the ability of the microorganism to  control the expression of plant genes encoding regulators of photosynthesis [46]. I didn’t find this fact in this reference.

8)    Line 417: Biofilm? maybe better membrane?

The article may be published after a minor revision.

Author Response

Please see the attachment. Thank you very much.

Author Response File: Author Response.docx