Effects of Exogenous Salicylic Acid (SA), 6-Benzylaminopurine (6-BA), or Abscisic Acid (ABA) on the Physiology of Rosa hybrida ‘Carolla’ under High-Temperature Stress

Round 1

Reviewer 1 Report

Dear Editors and Authors,

 

Thank You for giving me the opportunity to review the manuscript entitled: “Effects of exogenous salicylic acid (SA), 6-benzylaminopurine (6-BA) or abscisic acid (ABA) on the physiology of Rosa hybrida ‘Carolla’ under high temperature stress”.

 

[94]The materials and methods section need more details,

[125] include the settings for the Licor and used chamber,

[130] add more details how samples were prepared

[175] u are describing the soluble sugar content measurement in this section, but then writing again about proline content etc. how soluble sugars were measured?

[211] explain what is L1, L2, L3, L4 on the graphs, it’s not in the description

[204] indicate the statistical significant differences between the experimental groups into the graphs.

[299] discussion is poorly described, hormones need to be more described in the context of heat temperature. The photosynthesis parameters are almost completely forgotten in the discussion, especially the effect of ABA must be explained, why it leads to increased transpiration, was the experiment properly designed, are there other examples of such response described by other authors. The mechanism how PGRs increase the activity of antioxidant enzymes must be carefully explained, same case for the proteins and sugar content, what mechanisms trigger this response? Moreover, why higher concentrations of PGRs had weaker response in most of the analyzed parameters?

Author Response

Please see the attachment.

Reviewer 2 Report

The manuscript by Wang et al. is of great interest for the effects of plant growth regulators on high temperature stress. The studies were elaborately planned, and the experiments were well executed. I have some minor comments that should be addressed to possibly strengthen the paper.

1)     The authors performed experiments with spraying leaves with various concentrations with plants hormones. Plant leaves possess physical barriers such as wax layer. Have the authors considered suppling these plant hormones through root system instead of spraying directly on the leaves.

2)     JA and JA-Ile are known plant hormones that play important roles in plant biotic and abiotic stresses. Have the authors looked at levels of JA or JA-Ile during these treatments? It is all well documented that plant hormone signaling is an intricate system. The interplays between plant hormones tightly regulate plant responses to stresses. Measuring the changes of endogenous levels of these plant hormones would shed more lights on how they affect stress responses.

3)     The authors looked at superoxide dismutase and peroxidase. Lipoxygenase was also documented to play roles in lipid peroxidation during plant response to stress. This should be included, or at least discussed.

4)     Endogenous levels of these plant hormones should be mentioned in introduction.

5)     The unit for ABA concentration should be the same as SA and 6-BA.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

The review topic is really interesting and the manuscript is well written. Therefore, the manuscript has some problems that are listed below:

 

1) Please, uniformize the unit of SA (mmol/L), 6-BA (µmol/L), ABA (mg/L). If the authors decide to maintain the unit as mol/L, add also the concentration in terms of mg/L to other study be able to compare with your results.

2) Line 99 – what is RH? Please, define it.

3) Lines 109-112. Please, explain why these concentrations were used. Why are they different in the same group? For example, L1 (Low): 0.5 mmol L-1 SA, 109 10 μmol L-1 6-BA or 10 mg L-1 ABA. Please, also explain why these chemicals were selected for this research.

4) The authors should add statistic analysis to analyze your data.

5) The authors should create a table comparing the application of SA, 6-BA, ABA in other studies under temperature stress. Please, cite also the disadvantages of using these chemicals. The discussion should be improved significantly.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Dear Editors and Authors

I find this manuscript significantly improved, I can only sugest at poin1 to add some parameters listed below:

Point 1: [125] include the settings for the Licor and used chamber,

Response 1: The CO2 concentration in the LI-6400 leaf chamber (Ca) was set at 400 μmol CO2 mol−1 air, the leaf temperature at 25 °C, and the relative humidity (RH) of the incoming air at 65–70%. 

Answer:

Please include also what was the flow rate and light intensity.

Author Response

Answer: Please include also what was the flow rate and light intensity.

The flow rate was set to 500 μmol s^-1, Photosynthetic photon flux density (PPFD) was 1800 μmol m^-2 s^-1.