Combinatorial Effects of Glycine and Inorganic Nitrogen on Root Growth and Nitrogen Nutrition in Maize (Zea mays L.)
Round 1
Reviewer 1 Report
Comments: -
In the present study entitled “Combining glycine with inorganic nitrogen promotes root 1 growth and nitrogen nutrition in maize (Zea mays L.)” authors have demonstrated the effects of organic and inorganic nitrogen supplements on root growth, nutrient metabolism, assimilation in maize and its content in the soil. They have also suggested the co-application of organic and inorganic nutrition to the plants for enhancing root growth and root surface area so that nutrient use efficiency can be increased in crop plants. As practical aspects in crop improvement, the manuscript is technically sound except estimation of enzymes pertain to nitrogen metabolism and assimilation in plant. However, the manuscript is pertains to some pit-falls which need to be improve for global acceptance. The following comments were observed during review of the manuscript:
Comment #1 – It is just suggestion to change the title of manuscript. Authors can write the suggestive title “Combinatorial effects of glycine and inorganic nitrogen on root growth and nitrogen nutrition in maize (Zea mays L.)”.
Comment #2 - Authors must check and rectify merging of the words in whole text of manuscript. See line number 20 “Plant aboveground and belowground”.
Comment #3 - Authors should clear that it is the right way to denote NO3- -N and NO4+ -N.
Comment #4 – The images must be improved with high resolution. Some images are not visible.
Comment #5 – Authors have stated that “Six roots were selected from each plant to determine the root hair length. It must be clarified that whether 6 roots from six plants?
Comment #6 – Authors should note that the English language should be improved at various statements. It seems to be less readable.
Comment #7 – A technical issue came in mind that why do authors have not estimated the respective enzymes or expression of 1-2 nitrogen metabolic genes during the treatments. It would be more authenticated about nitrogen metabolism and assimilation in maize, if authors have included some molecular work. Authors can clarify whether it is possible to incorporate the molecular work at this stage?
Comment #8 – Why do authors have not included water control and glycine alone in the treatments?
Comment #9 – Authors have claimed that combined effects of the work related to organic and inorganic nutrition have not be reported in crop plants in the statement of “how the coapplication of 18 organic and inorganic nitrogen affects root growth, plant nitrogen metabolism, and soil nitrogen content is still unclear”. So authors must clarify that whether this is novel work or not then cite references of the previous work in other crop plants.
Comment #10 – Authors must improve the conclusion by making it quantifiable.
English language should be improved at various statements. It seems to be less readable
Author Response
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Reviewer 2 Report
1. Line 90: Are the basic properties derived from the soils after mixing with river sands present here?
2. Lines 139 to 141: It is unclear what was evaluated based on the stained small root segment.
3. Line 144: Does it mean that the repetitive soils in the pot samples were mixed and collected?
4. Line 159: To which treatment does “Amm + Nit + Gly” refer? Please indicate it in the Materials and Methods section.
5. Lines 159 to 160, based on Table 1, the plant height and leaf area following the Amm, Amm+Nit, and Amm + Nit + Glu treatments were also significantly higher than the values from the Nit treatment.
6. Lines 224 to 226, based on Figure 5b, it was concluded that root surface area was one of the important factors affecting the changes in shoot physiological and biochemical indicators. Please provide the evidence that supports root surface area being the most important factor.
7. Line 279, the conclusion section should include some important experiment results.
1. Line 54: The comparative form of adjectives, such as “higher”, is generally used with "than" to make a comparison between two things.
2. Lines 210 to 212: This sentence needs to be rewritten to make it easier for readers to understand.
3. Line 223: The word “significant” should be changed to “significantly”.
4. Line 279: The word “indicate” should be changed to “indicates”.
5. Lines 293 to 294: This sentence needs to be rewritten to make it easier for readers to understand.
Author Response
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Reviewer 3 Report
Combining glycine with inorganic nitrogen promotes root growth and nitrogen nutrition in maize (Zea mays L.)
Major revision
1. How were glycine and inorganic nitrogen concentrations determined in the study?
2. What controls did you use in your experiments?
3. The root growth was quantified in what way?
4. In assessing maize nitrogen nutrition, what metrics were used?
5. Did the experimental conditions mimic natural conditions?
6. How consistent were the results of any replications of the study?
7. How were the data analyzed statistically?
8. All your results are accompanied by p-values?
9. A power analysis was conducted, and how was the sample size determined?
10. How is 'significance' defined in this context, and are the results statistically significant?
11. What accounts for the observed increase in root growth and nitrogen nutrition?
12. Can these results be generalized to other crop species?
13. Have any trade-offs or downsides been observed with the treatment, such as increased disease susceptibility?
14. What is the comparison between the results and the existing literature?
15. Based on your findings, what further studies would you recommend?
16. What impact might these findings have on current agricultural practices?
17. Do we need to consider possible environmental impacts, such as leaching of inorganic nitrogen?
18. Does your study have any limitations that have not been addressed?
19. Can other confounding factors be eliminated by the methodology?
20. Are there any other unexplored benefits or risks associated with the combination of glycine and inorganic nitrogen?
Major revision
Author Response
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Reviewer 4 Report
Dear Authors,
Your article has been written as original and descriptive. However, if you revise my criticisms below, your article would be of much better quality.
- Which fertilizer form was used as the source of NO3 -N and NH4—N.
- In the discussion, the difference between ammonium results and nitrate results should be discussed in detail. Forexample, the solubility of NH4 -N and its uptake by plants are more affected by soil pH, organic matter content and mineral substances than NO3 -N uptake. Therefore, the differences between soil nutrient content and applications should be discussed.
Results section should be improved. Among the applications, the most appropriate should be specified. Important emphasis should be placed on the recommendations and how this study can be applied in field conditions.
Best regards,
Author Response
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Round 2
Reviewer 1 Report
Authors can improve the Figure 1a and Figure 3 by increasing thier brightness at appropriate level.
Author Response
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Author Response File: Author Response.docx
Reviewer 2 Report
1. Table S1 is better to move into the text.
1. Line 199, 202, 212, 224, 236, 268, 334, 378, 419: The phrase “compared to” should be changed to “than”.
2. Line 201: "compared to other" should be changed to "among all".
Author Response
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Reviewer 3 Report
Accepted
Accepted
Author Response
Thank you for your recognition of our manuscript.
