Review Reports - Determination of Physiochemical Characteristics Associated with Various Degrees of Cadmium Tolerance in Barley Accessions

Round 1

Reviewer 1 Report

Tahir et al., provide an important subject in Cd stress struggling in agriculture by establish a species selection guideline however I found major comments that should be considered one by one to improve this work mentioned as follow:

1- In the abstract in L 18 correct the unit into µM

2-“Compared to the untreated plants, treatments with Cd lowered germination percentages by 1.15, 1.79, and 3.84% for 125, 250, 22, and 500 µM concentrations, respectively”, Authors didn’t mention in which barley accessions they got these results and so on for the coming statements. Otherwise, you should mention that “the average of increase percentages among barley accessions ranged as, for example, 1.15 - 3.00, 1.79 - 4.00, and 3.84 - 5.00 % for 125, 250, 22 and 500 µM concentrations, respectively.

Introduction

2-In general, all species of plants can tolerate the stress of heavy metals at different rates, depending on the variety of plants and the type of heavy metal. Please add the reference. Also, you should differentiate in one main paragraph the diverse strategies of HMs tolerance in HM- sensitive, tolerant, and accumulator plants and changes that occur in relevant physio-chemical parameters in each.

3-Mention previous studies manifested the sensitive physio-chemical parameters judging HMs tolerance that were used as selection criteria in their conclusions.

Material and method

1- It is not clear how much water contaminated with Cd was added to the Petri dishes of Cd treatment.

2- It is not clear whether dishes were supplied by more Cd-contaminated water after seed imbibition or Cd was supplied as a single dose then add dist. water.

3- What is AC add full description. Please, mention in some detail the methodology of radical scavenging activity by DPPH determination.

4- Why did not authors determine Cd tissue content? Please add the data of Cd tissue content. Cd content and its translocation factor is a very important criterion for judging species tolerance and how can species manage Cd in their tissues.

In discussion

1- In L 542 “the decrease in nutrient uptake and photosynthetic efficiency, which weakens their photosynthetic production capacity, and the increase in production of ROS, which damages the cell membrane and macromolecules” Add this reference https://doi.org/10.3389/fpls.2022.1004173 regarding nutrient uptake imbalance for example Fe deficiency due to Cd stress affect photosynthetic efficiency and causing of membrane lipid oxidation.

2- In L 546 “The root organ accumulated a high amount of Cd, which had a negative impact on the roots' morpho-physiological process, leading to a decline in underground biomass that was more severe than the decline in aboveground biomass” . I am wondering how cold author mention that "The root organ accumulated a high amount of Cd" while they did not determine Cd content in root or any organ of the plant. Authors have to interpret this statement they can mention that “The lower content of Cd in aboveground than roots jointed with the absence of toxicity symptoms in these Cd-stressed accessions could rationalize the importance of Cd root-retention mechanism established by tolerant accessions in order to protect aerial parts versus the toxic influence of Cd. Then use this https://doi.org/10.1007/s42729-022-00966-x to document your discussion.

Again when discussing the seven Physio-biochemical parameters you should focus on how the extent of sensitive and tolerant accessions differs based on the tested Physio-biochemical parameters. Use this article https://doi.org/10.3390/plants11192556 to discuss the suggested mechanism related to the tolerance degree in each category (sensitive or tolerant)

The conclusion and results sections need to be shortened

Author Response

Manuscript number: agronomy-2432698

Paper title: Determination of Physio-Chemical Characteristics Associated with Various Degrees of Cadmium Tolerance in Barley Accessions

Authors: Nawroz Abdul-razzak Tahir, Djshwar Dhahir Lateef, Kamil Mahmud
Mustafa, Kamaran Salh Rasul, Fawzy Faidhullah Khurshid

Dear Editor and Reviewer

The authors would like to thank the area editor and the reviewers for their precious time and invaluable comments. We have carefully addressed all the comments. The constructive comments/ suggestions by the reviewer are really appreciated. We have now completely revised the manuscript. All corrections in English language and updating of information are highlighted by the red lines. The corresponding changes and refinements made in the revised paper are summarized in our response below. The actual comments and questions of the reviewer are in BOLDED RC, and the author's responses are italicized AR.

Comments of Reviewer and Answer

RC1. In the abstract in L 18 correct the unit into µM

Thank you. The unit has been corrected

RC2. Compared to the untreated plants, treatments with Cd lowered germination percentages by 1.15, 1.79, and 3.84% for 125, 250, 22, and 500 µM concentrations, respectively”, Authors didn’t mention in which barley accessions they got these results and so on for the coming statements. Otherwise, you should mention that “the average of increase percentages among barley accessions ranged as, for example, 1.15 - 3.00, 1.79 - 4.00, and 3.84 - 5.00 % for 125, 250, 22 and 500 µM concentrations, respectively.

Thank you. The abstract section has been modified

RC3.In general, all species of plants can tolerate the stress of heavy metals at different rates, depending on the variety of plants and the type of heavy metal. Please add the reference. Also, you should differentiate in one main paragraph the diverse strategies of HMs tolerance in HM- sensitive, tolerant, and accumulator plants and changes that occur in relevant physio-chemical parameters in each.

Thank you. The reference and the diverse strategies of HMs tolerance have been added to the revised manuscript.

RC4. Mention previous studies manifested the sensitive physio-chemical parameters judging HMs tolerance that were used as selection criteria in their conclusions.

Thank you. The previous studies manifested the sensitive physio-chemical parameters have been added to the revised manuscript.

RC5. It is not clear how much water contaminated with Cd was added to the Petri dishes of Cd treatment.

Thank you. The procedure of treatments has been modified and improved.

RC6. It is not clear whether dishes were supplied by more Cd-contaminated water after seed imbibition or Cd was supplied as a single dose then add dist. water.

Thank you. The procedure of treatments has been modified and improved.

RC7. What is AC add full description. Please, mention in some detail the methodology of radical scavenging activity by DPPH determination.

Thank you. The full description and detail have been added

RC8. Why did not authors determine Cd tissue content? Please add the data of Cd tissue content. Cd content and its translocation factor is a very important criterion for judging species tolerance and how can species manage Cd in their tissues.

The determination of Cd in different organs of seedling was not performed because the seedling was only 8 days old, and thus the quantity of tissue collected was insufficient for the determination of Cd content in seedling roots and shoots by ICP. Furthermore, the separation of seedlings into root and shoot results in the collection of too little tissue, which cannot be used in Cd analysis.

RC9. In L 542 “the decrease in nutrient uptake and photosynthetic efficiency, which weakens their photosynthetic production capacity, and the increase in production of ROS, which damages the cell membrane and macromolecules” Add this reference https://doi.org/10.3389/fpls.2022.1004173 regarding nutrient uptake imbalance for example Fe deficiency due to Cd stress affect photosynthetic efficiency and causing of membrane lipid oxidation.

Thank you. This reference has been added

RC10. In L 546 “The root organ accumulated a high amount of Cd, which had a negative impact on the roots' morpho-physiological process, leading to a decline in underground biomass that was more severe than the decline in aboveground biomass” . I am wondering how cold author mention that "The root organ accumulated a high amount of Cd" while they did not determine Cd content in root or any organ of the plant. Authors have to interpret this statement they can mention that “The lower content of Cd in aboveground than roots jointed with the absence of toxicity symptoms in these Cd-stressed accessions could rationalize the importance of Cd root-retention mechanism established by tolerant accessions in order to protect aerial parts versus the toxic influence of Cd. Then use this https://doi.org/10.1007/s42729-022-00966-x to document your discussion.

Again when discussing the seven Physio-biochemical parameters you should focus on how the extent of sensitive and tolerant accessions differs based on the tested Physio-biochemical parameters. Use this article https://doi.org/10.3390/plants11192556 to discuss the suggested mechanism related to the tolerance degree in each category (sensitive or tolerant)

Thank you. The interpretation and reference have been added

RC11. The conclusion and results sections need to be shortened

Thank you. The conclusion has been shortened

Best regards

Author Response File: Author Response.docx

Reviewer 2 Report

please open the attached file

Comments for author File: Comments.pdf

English Language of the manuscript is good

Author Response

Manuscript number: agronomy-2432698

Paper title: Determination of Physio-Chemical Characteristics Associated with Various Degrees of Cadmium Tolerance in Barley Accessions

Authors: Nawroz Abdul-razzak Tahir, Djshwar Dhahir Lateef, Kamil Mahmud
Mustafa, Kamaran Salh Rasul, Fawzy Faidhullah Khurshid

Dear Editor and Reviewer

Comments of Reviewer and Answer

RC1. Regarding the abstract section:

The results section of the abstract is reviewed and rewritten. In addition, we explained why the current approach were chosen. Then, a final, researched conclusion was presented shortly and precisely.

RC2. Regarding the introduction section:

AR, All feedback and suggested changes were accepted. In response to making a connection and filling gaps in the research, this work is completely new in our area because many researchers believe that cadmium is not a major problem in our region, but we think differently because these barley accessions were adapted for salt, drought, and many other stresses, and we aimed to find out whether these materials can also withstand cadmium heavy metals so that it can be a resource for those places suffering from this problem.

RC3. Regarding the result section:

AR, 1-To better illustrate how the resistant and susceptible barley accessions fared in the presence of 250 and 500 µM compared to control circumstances, several images of these barley varieties have been added to the supplementary section. There were no discernible changes phenotypically between the treated with 125 µM and untreated conditions, thus this group was thrown out.

2- In this study, we employed numerous variables phenotypically, physiologically, and biochemically to offer us clear behaviors of tested barley accessions. However, it is true that completing both lab and field experiments is very crucial to validate the reliability of the screening at this point. This will be our next step.

3- Regarding not conducting or identifying the expression of specific genes, we searched for those genes whose expression is related to cadmium resistance and chose the HvPAA1 gene to be included in this investigation based on previous research, but at the time of conducting this research, all real-time PCR were busy analyzing the blood passions affected by corona virus, and the -80 freezer in our department was broken. In addition, we have another project about the testing the effects of Cd on the growth and productivity of tolerant and sensitive barley plants cultivated in the pots under plastic house to find the correlation between the results of in vitro and plastic house. In this experiment, we will analyse the expression of some genes related to the Cd tolerance.

RC4. Regarding the conclusion section:

This section has been improved by the addition of a conclusive conclusion, a future view, and a recommendation in order to make it more legible and easily available to anyone who are interested in learning more about the topic.

RC5. Regarding the conclusion section:

We checked each and every reference to make certain that it was properly cited in the text and that it was as recent as possible.

Best regards

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors have adequately improved their paper and addressed the recommended corrections. Accordingly, I recommend the acceptance

Reviewer 2 Report

the authors have made all the corrections in the manuscript and replied well to all inquiries well. Therefore, I recommend publishing the manuscript in the Agronomy journal