Water Uptake and Hormone Modulation Responses to Nitrogen Supply in Populus simonii under PEG-Induced Drought Stress
, Na Wu 1 and Zhan Bian 1,3,*
Round 1
Reviewer 1 Report
Comments and Suggestion for Authors
Water Uptake and Hormone Modulation Responses to Nitrogen Supply in Populus simonii under PEG-induced Drought Stress.
The subject of the work is very interesting and relevant since climatic alterations are already being responsible more frequent extreme events, as drought periods, which negative influences the growth of forest plants.
Figure 10. A schematic model of responses to nitrogen supply in drought in Populus simonii under drought stress. Please adjust in the results section.
Line No 503, 504, Please correct the sentence
Line No 16, Please change “hydroponic culture condition” to hydroponic solution
Line No 36, Please change the “Lack” to deficit.
Line No 37-38, Please correct the sentence
Line No 40, what do you mean poor soils and dry sit (Please clear the sentence)
Line No 42-50, please make the sequence in the introduction section, and complete describe the introduction of species in line 50.
Line 53, please add the CO2 assimilation rate
Line No 58, please use another appropriate word cascades
Line No 86-89, please correct the sentences
Line No 92, 2 cm in diameter means stem diameter, and diameter is always measure in mm not in cm, please correct it
Line No 99, Please use the same pattern in the whole text of manuscript, seedlings, saplings and plants. Don’t be use the different style.
Line No 112, What is the root character? root measurement, please correct the sentences.
Line No 123, computed, use another word calculated.
Line No 117 and 125, Please follow the correct format of journal for Reference style in the text.
Line No 127, centrifugation 10,500 × g, please correct it.
Line No 131, Spectrophotometry (Please add the details of instrument)
Line No 174, Measurement of Antioxidants enzyme, according to my point of view there is no need of Supplementary materials and method for only this section. Please adjust SOD, POD, CAT and APX methodology in the material and methods section.
Line No 178, IAA and ABA contents please describe some methodology.
Results section: Please improve the sentence structure in all the section of results in the manuscript.
Line No 205, Chlorophyll content, where you measure the chlorophyll content was not mentioned in the material and methods section. Please check it very carefully.
Line No 219, Little effect, minor effect please replace the world.
Line No 327, by drought stress is not suitable word please use the under the drought stress.
Line No 390, What do you mean by original environment? Please use the appropriate word.
Line No 395, P. simonii survive under drought stress, please correct it.
Line No 397, The growth and biomass parameters were decreased under drought stress, and how is possible the electrolyte leakage was not affected under drought stress. Please justify it
Line No 403, what is Attacked? Use the appropriate words.
Comments for author File: 
Comments.pdf
Author Response
Please see the attachment.
Author Response File: 
Author Response.doc
Reviewer 2 Report
Li et al. evaluated the effect of PEG-induced drought stress and low N supply on Populus simonii plants in hydroponics evaluating several physiological, biochemical and molecular aspects. The experiment is well conducted and several analyses were carried out to better understand poplar response. However, in my opinion results can be further discussed. I have reported several comments and suggestion in the attached file.
As I reported in the attached file, Table 1 is missing and some results in supplementary material deserve to be mentioned in the main manuscript (Supplementary Table S2) while some figures can be joined (Figures 5 and 6), simplified (Figure 2), or removed (Figure 3).
Authors did not clarify the way in which they have chosen the isoforms for gene transcription analysis and how they have retrieved primers. If they have designed them, M&M are lacking also regarding the check of amplicon sequences. Moreover, the selected isoforms must be further described.
I also suggest to uniform the definition of treatments, as example PEG-induced stress, drought stress and osmotic stress were used alternatively along the text as well as low N treatment and 0.01 mM NH4NO3. I suggest to be clearer the use of abbreviations for all treatments consistently throughout the manuscript.
Comments for author File: Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.doc
Round 2
Reviewer 2 Report
Authors resolved some of my comments but important points remain to be deepened.
Authors again did not clarify the way in which they have chosen the isoforms for gene transcription analysis. Since in literature there are many works regarding aquaporins and poplar under drought it is important to explain because as example PIP2;1 has been chosen rather than PIP1;1 or 2;2 or 3;1. The choice of isoforms seems casual. Moreover, authors have designed their own primers but no verify about the accuracy of amplification has been reported (amplicon sequence, melting curve, electrophoresis gel with amplicon lenght, etc.). Please carefully revise this section.
Also methods on biomass calculation and RWC are confusing, please specify how you the turgid weight measures were conducted and if dry biomass calculation was obtained through a fresh to dry biomass ratio using the fresh weight before the grinding with liquid nitrogen. Unit of measures in gas exchange are wrong and generally several typos are present along the manuscript.
The definitions of treatments are still not consistent throughout the manuscript (e.g., low N or 0.01 mM NH4NO3 are mutually used).
I reported minor comments in the attached file
Comments for author File: Comments.pdf
Author Response
Dear Editor,
We greatly appreciate both your help and that of the referees in helping me improve this paper and hope that the revised manuscript is suitable for publication. I hope this revision makes my manuscript more acceptable. We have re-submitted our manuscript and our point-by-point responses are detailed below.
Reviewer #2：
Q1: Authors again did not clarify the way in which they have chosen the isoforms for gene transcription analysis. Since in literature there are many works regarding aquaporins and poplar under drought it is important to explain because as example PIP2;1 has been chosen rather than PIP1;1 or 2;2 or 3;1. The choice of isoforms seems casual. Moreover, authors have designed their own primers but no verify about the accuracy of amplification has been reported (amplicon sequence, melting curve, electrophoresis gel with amplicon lenght, etc.). Please carefully revise this section.
A：The selected isoforms and primers has been described. “Key genes involved in water uptake and hormone modulation were selected for gene transcription analysis [8, 17].”
Q2: Also methods on biomass calculation and RWC are confusing, please specify how you the turgid weight measures were conducted and if dry biomass calculation was obtained through a fresh to dry biomass ratio using the fresh weight before the grinding with liquid nitrogen.
A：Yes, dry biomass calculation was obtained through a fresh to dry biomass ratio using the fresh weight before the grinding with liquid nitrogen. “A part of roots (c.2g) were excised from the root system, scanned with a scanner (HP Scanjet G4050) and analyzed with a WinRHIZO root analyzer system (WinRHIZO version 2007b, Regent Instruments, Canada). Six leaves from each plant were submerged in water for 24 h to measure the leaf saturated weight (SW). The remaining roots and leaves were wrapped with tinfoil, ground into fine powder in liquid N with a mortar and pestle and stored at -80°C. Frozen powder (c.100mg) from each plant was dried at 60 °C for 72 h to determine dry biomass and the fresh-to-dry-mass ratio.”
Q3: Unit of measures in gas exchange are wrong and generally several typos are present along the manuscript.
A：The unit of measures in gas exchange had been revised.
Q4: The definitions of treatments are still not consistent throughout the manuscript (e.g., low N or 0.01 mM NH4NO3 are mutually used).
A：All statements of low N had been changed to 0.01 mM NH4NO3.
Q5: I reported minor comments in the attached file
A：All comments had been revised. For example, Fig 5 and 6 were merged. See the revised manuscript with tracked changes.
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
