Are Traditional Lima Bean (Phaseolus lunatus L.) Landraces Valuable to Cope with Climate Change? Effects of Drought on Growth and Biochemical Stress Markers

Round 1

Reviewer 1 Report

 

The manuscript entitled "Are traditional Lima Bean (Phaseolus lunatus L.) landraces valuable to cope with climate change? Effects of drought on growth and biochemical stress markers” reports the effect of drought stress in three cultivars of P. lunatus plant (two from local Valencian traditional crops and one as commercial cultivar) using growth and biochemical stress markers. The results based on growth and biochemical results show that the commercial variety of P. lunatus more tolerant under high intensity of drought stress. Their data were supported with appropriate analyses which are known for plant response under abiotic stress.

Following points need to be addressed/modified:

1.  The introduction section part is long, could be summarised, and focus mainly on the growth and biochemical markers as tools to select tolerant species

2.  Try to avoid the long phrases (par examples lines 74-77, 273-275, etc.), at some points it was difficult to understand the sentence

3.    Remove the black borders around the figures (2 to 7)

4.   The significant letters for figures (2 to 7) are confusing, better to put them in different colors or in bolds to understand the significant differences within each cultivar or between the cultivars. Also, the same for Table 1.

5.   Section 3.5, interpretation of the results is unclear, and the illustration of figure 8 is the same

6.   The conclusion section can be written more detailed.

All the best, 

 

Author Response

Thank you very much for the positive review carried out. Below, we include in bold the replies to the comments.

1. The introduction section part is long, could be summarised, and focus mainly on the growth and biochemical markers as tools to select tolerant species

We understand the point of this appreciation. However, we believe that general information, for example, on the 2030 Agenda and the effects of climate change serves to frame the work in the current context of climate emergency and food security and is of interest to many readers.

2. Try to avoid the long phrases (par examples lines 74-77, 273-275, etc.), at some points it was difficult to understand the sentence

We have rewritten these sentences, reducing their length and believe that they are now better understood. Apart from these sentences pointed out by the reviewer, a revision of the text as a whole has been carried out, improving the wording of some fragments to ensure the clarity of what has been presented.

3. Remove the black borders around the figures (2 to 7)

We have removed the black borders of figures 2 to 7.

4. The significant letters for figures (2 to 7) are confusing, better to put them in different colors or in bolds to understand the significant differences within each cultivar or between the cultivars. Also, the same for Table 1.

We have worked on figures 2 to 7 (and Table 1), introducing bolds to help differentiating each cultivar and between the cultivars.

In addition, extra effort has been made to improve the clarity of the figures in order to help in the interpretation of the results. To this end, the figures have been enlarged and the font size reduced.

5. Section 3.5, interpretation of the results is unclear, and the illustration of figure 8 is the same.

We addressed the appreciation and realised that figure 8 and the explanation of the figure was probably not entirely clear. We have added in subfigure 8a the measured intensity and expanded the explanations both in the figure and in the results. New lines 510-517 include now this explanation: “Taking the base-lines depicted in Figure 8 to measure peak currents, it can be ob-served that the intensity of the peak at 0.67 V (I670) relative to the wave at 0.0 V (I0) provides information on the ROS scavenging capacity of the cultivar when comparing control and water-stressed plants. Therefore, as the difference in the I670/I0 ratio between control and stressed plants increases, a higher capacity can be deduced due to a higher enzymatic mobilisation under stress conditions. This difference decreases from the Peru genotype to Pintat and Ull de Perdiu, these two being essentially identical; i.e.: (I670/I0)Peru < (I670/I0)Pintat ≈ (I670/I0)Ull de Perdiu.”

6. The conclusion section can be written more detailed.

The conclusions have been rewritten, improving them by adding information, as requested.: “As a corollary, P. lunatus, considering the three analysed cultivars, has proved to be a relatively water stress-tolerant species, as revealed by the slight or non-significant variations of the morphologic and biochemical markers. Subsequently, overall low levels of oxidative stress were found. Notwithstanding, just contrary to the germination phase, the commercial variety appears to be the less stressed, taking into account the global results: lower decreases in growth parameters, unaffected pigment contents, the highest increase of K+, a non-significant increase of MDA, low augment of polyphenol compounds or an earlier response of Pro. The breeders' selective efforts are especially aimed at improving this phase, so the results presented here are probably a consequence of this selective pressure. Besides, most of the biochemical parameters evaluated contributed to unravelling the water stress response of Lima bean, except for ions, where only K+ and Ca2+ leaves/roots ratio generated valuable information. Finally, the voltammetric method was demonstrated to be a good and quick tool to evaluate oxidative stress and, therefore, water stress in cultivated plants. The I520/I670 ratio measured in the four humidity conditions showed concordant results with those related to TPC and TF, antioxidant compounds that react with ROS species.”

We believe that it now includes the details expected by the reviewer.

Please, find attached the manuscript with the changes tracked.

Author Response File: Author Response.docx

Reviewer 2 Report

Dear Authors,

Congratulation on your great work. The paper is well written, the results are well explained and the discussion shows the importance of the results obtained.

I would recommend inserting the following information in the Material and Methods section:

- Number of plants and replicated used in the experiments;

-  Stage or age of plants when the characteristics described on items 2.4, 2.5, 2.6, and 2.7 were evaluated;

 

I understand the Authors have as objective ii: evaluate if water stress tolerance is enhanced in commercial varieties by plant breeding, or rather in local landraces through years of cultivation. However, because of the number of genotypes evaluated (one commercial variety and two landraces), conclusions related to the difference between these two groups could be biased. I believe conclusions should be restricted to the specific genotypes used in the study.

Sincerely,

 

Author Response

Thank you very much for the positive review carried out. Below, we include in bold the replies to the comments.

R1.- Number of plants and replicated used in the experiments;

The last sentence of the first paragraph of section 2.2 includes the requested information: "five plants were used per cultivar and treatment". (line 164)

R1.-  Stage or age of plants when the characteristics described on items 2.4, 2.5, 2.6, and 2.7 were evaluated;

Thank you very much for this appreciation. We have modified the last part of the second paragraph of section 2.2 this way “These conditions were maintained until plants subjected to the strongest water deficit showed visible signs of deterioration, 18 days after the beginning of the treatments, when the experiment was concluded and all plants were harvested". (lines 170-171).

The title of section 2.3. has also been modified and now states “Plant Sampling and Growth Parameters” (line 175). We have also included a new sentence at the end of the section: “Plant samples used for determination of biochemical parameters were stored frozen at -80 °C.” (lines 185-186).

R1. I understand the Authors have as objective ii: evaluate if water stress tolerance is enhanced in commercial varieties by plant breeding, or rather in local landraces through years of cultivation. However, because of the number of genotypes evaluated (one commercial variety and two landraces), conclusions related to the difference between these two groups could be biased. I believe conclusions should be restricted to the specific genotypes used in the study.

Yes, you are right: conclusions are restricted to the specific genotypes used in the study. To emphasise this aspect, in the conclusions section it has been clarified that the results refer to the three analysed cultivars (line 626).

Reviewer 3 Report

Thank you for the opportunity .

Appreciated the author's effort in working on the area of climate change.

Nicely covered introduction and objective of the study, well explained results and discussion. Just one comment: could you re-draw or edit figure 2 especially 2e and 2f.

Kind regards

Author Response

Thank you very much for the positive review carried out. Below, we include in bold the replies to the comments.

R2. Nicely covered introduction and objective of the study, well explained results and discussion. Just one comment: could you re-draw or edit figure 2 especially 2e and 2f.

We have edited some of the graphs in figure 2 (especially 2e and 2f), trying to avoid the overlapping of some of the letters. We have also revised the rest of the figures, improving figure 7 in the same way.