Dynamic Traits of Intracellular Water and Salt Based on Electrophysiological Measurements During Adaptations of Three Mangrove Species Under Salinity Stresses

Round 1

Reviewer 1 Report (New Reviewer)

Comments and Suggestions for Authors

Comment 01

The manuscript titled "Dynamic traits of intracellular water and salt based on electrophysiology and adaptations of three mangrove species under salinity stresses" (Manuscript ID: horticulturae-3440307), submitted to Horticulturae, presents an innovative study on the intricate mechanisms of water and salt dynamics in mangrove species under salinity stress. The research employs advanced electrophysiological sensors to elucidate the synchronous variations in intracellular water and salt metabolism across three mangrove species—Rhizophora stylosa, Kandelia candel, and Aegicerascorniculatum. by exploring these dynamics under varying salinity conditions, the study offers a profound understanding of the adaptive strategies of these plants, such as salt exclusion, ultrafiltration, and intracellular water balance. The findings are particularly significant for the scientific comunity as they bridge critical knowledge gaps in plant salt tolerance mechanisms, with potential applications in ecological restoration and the management of saline environments. Additionally, the socio-economic implications of this work are substantial, given the role of mangroves in coastal protection, biodiversity conservation, and sustainable landscaping in saline and coastal zones.  the study’s novel methodology and impactful results contribute to advancing both theoretical understanding and practical applications in horticulture and environmental sustainability.

Comment 02

the use of electrophysiological parameters measurement and dynamics model parameters calculation in the manuscript is notably innovative.  This methodological approach represents a significant advancement in studying plant physiological responses, allowing for non-invasive and precise detection of intracellular processes. Such techniques enhance the understanding of dynamic water-salt metabolism and provide valuable tools for exploring plant adaptability under stress  conditions.

Comment 03

to enhance the depth and analytical rigor of the work, it is recommended to include a comprehensive correlation analysis among the various studied parameters, integrating the effects of the different salinity treatments. such an approach would allow the authors to uncover potential interdependencies and patterns that could enrich the understanding of the adaptive mechanisms.  Additionally, incorporating a Principal Component Analysis (PCA) could provide a holistic perspective by summarizing the key variables driving the observed responses and differentiating the adaptive strategies among the mangrove species.

Comment 04

In the presented tables, numerical values are occasionally reported with up to four decimal places. the scientific relevance of such high precision is unclear, as it does not appear to add meaningful information to the findings and may unecessarily clutter the tables, making them harder to interpret. It is suggested that  the authors limit the numerical precision to one or two decimal places, which is typically sufficient for biological and ecological data.

Comment 05

Regarding Figure 4, the addition of two supplementary parameters—Intrinsic Water Use Efficiency (IWUE) and Water Use Efficiency (WUE)- is recommended. These parameters, calculated as simple ratios, would provide valuable insights into the efficiency of water utilization under different salinity treatments, offering a more comprehensive understanding of the plants' adaptive strategies.

Comment 06

The manuscript predominantly relies on older references, with only one citation from 2024 and another from 2023 . While foundational studies are undoubtedly valuable, the inclusion of more recent literature is essential to reflect the latest advancements and ensure the study is grounded in the current state of knowledge.

Comment 07

The term "Photosynthetic parameters," as used in manuscript, does not accurately reflect the scope of the parameters measured. The study focuses on gas exchange parameters such PN, gs, Ci, and E, which are specifically related to photosynthetic gas exchange processes. However, "Photosynthetic parameters”  is a broader term that typically encompasses a range of measurements, including pigment concentrations, photosystem activities, enzymatic activities, and overall photosynthetic efficiency... It is recommended to adjust the  terminology throughout the manuscript to "Photosynthetic gas exchange parameters" or a similar term that more precisely describes the scope of the study, ensuring clarity and accuracy in the presentation of the research.

Comment 08

One notable omission in the manuscript is the lack of data on photosynthetic pigments. Considering the critical role of pigments such as chlorophyll and carotenoids in photosynthesis and plant stress responses, their quantification would have provided valuable complementary insights. The measurement of photosynthetic pigments using straightforward spectrophotometric methods is a well-established and relatively simple technique that could have enriched the study’s analysis of the physiological responses of mangroves to salinity stress.

Comment 09

• Please, make sure that all references have a corresponding citation within the text and vice versa .

• Please, double-check the spelling of the author’s names and dates and make sure they are correct and consistent with the citations.

• Please, spell out all journal titles in the references section.

• Please, make sure that all figures and tables are cited within the text and that they are cited in consecutive order.

• Please, spell al the abbreviations the first time when they are mentioned in the text.

Comment 10

I hope my remarks are not perceived as overly severe, as they stem from an appreciation of the potential demonstrated by the manuscript. The research addresses a significant and timely topic, and I believe it holds promise for contributing meaningfully to the field. My intent is to offer constructive feedback to help refine the work, ensuring it is published in its best possible form and has the strongest impact within the scientific community .

Comments on the Quality of English Language

The English could be improved to more clearly express the research.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report (New Reviewer)

Comments and Suggestions for Authors

The submitted Manuscript provides interest from the point of describing different behaviours of three different mangrove species. The Manuscript could be published with the reasonable data presented but requires revisions or rejection-revisions.

1) Title. Dynamic traits of intracellular water and salt based on electro- 2 physiology and adaptations of three mangrove species under 3 salinity stresses.

There was no pure electrophysiology (e.g. voltage clamp, patch clamp); then “electrophysiology” and “adaptations” are logically not linked. So, it’s better to change the title to e.g.

  Dynamic traits of intracellular water and salt during adaptations of three mangrove species under 3 salinity stresses.

Or

Dynamic traits of intracellular water and salt based on electrophysiological measurements during adaptations of three mangrove species under 3 salinity stresses.

Or somewhat else.

Still the electrophysiology is quite weak.

2) Abstract is not well written. Mangroves are not ornamental plants. Huge mangrove areas exist.

There is no water-salt metabolisms but water relations or water salt relations at least.

The other parts of the abstract do not  look not reasonable as well. The language is not ideal.

3) 2.1. Plant materials and treatments

Not well described: what was the size and age of the plants?

4) The method of Duan (Duan, R.; Xing, D.; Chen, T.; Wu, Y. Effects of Different Inorganic Nitrogen Sources of Iris Pseudacorus and Iris Japonica on Energy Distribution, Nitrogen, and Phosphorus Removal. HortScience 2022, 57(6), 698–707. https://doi.org/10.21273/HORTSCI16510-22.) is too mechanistic, it is not  published in a journal with high IF. Moreover, the properties of a capacitor are influenced by dielectric properties of the material inside, e.g. by cell walls, so changes in dielectric properties will change all the parameters under the same thickness. Hence, this part should be excluded and deleted. The Manuscript should be rewritten accordingly.

5) E.g. Table 3. The precision given is too high, it should be rounded. 313.7964±49.1411de

6) Plant height increment What are the units?  Per an hour, per a year, per a day?

7) Nernst equation is for a single cell, not for a group of cells, not applicable.

8) Supplementary.  The cell membrane proteins are most closely related to salt transport. The proportion of phospholipids, surface proteins (peripheral proteins) and conjugated protein (intrinsic proteins) on the cell membrane strongly affects the transport capacity of cellular substances, and ultimately affects the salt transport efficiency of plants.

There are specific ion channels and transporters for specific ions. E.g.

https://pubmed.ncbi.nlm.nih.gov/12221989/

and

Demidchik V, Tester M. Sodium fluxes through nonselective cation channels in the plasma membrane of protoplasts from Arabidopsis roots. Plant Physiol. 2002 Feb;128(2):379-87. doi: 10.1104/pp.010524. PMID: 11842142; PMCID: PMC148901.

Please, add more.

9) All the models composed are a rough approximation of the biological reality. The part about metabolism should be excluded; it doesn’t make sense. Energy in biology is due to metabolism, ATP, biochemical reactions etc.

The volume of experimental data and choice of objects are sufficient for publication. All the text should be rewritten in a more descriptive form with the final figure left.

The present Reviewer suggests rejection to correct the text.

Comments on the Quality of English Language

Could be better; understandable but have to be polished.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report (New Reviewer)

Comments and Suggestions for Authors

Dear Authors,

I recently had the opportunity to review your manuscript titled "Dynamic traits of intracellular water and salt based on electrophysiological measurements during adaptations of three mangrove species under salinity stresses" (horticulturae-3440307). Your study certainly presents elements of interest and novelty. After carefully reviewing the updated version, I appreciate the revisions and additions you've made.

I would like to thank you for taking my suggestions into account.

Kind regards,

Reviewer

Author Response

Comments 1:

Dear Authors,

I recently had the opportunity to review your manuscript titled "Dynamic traits of intracellular water and salt based on electrophysiological measurements during adaptations of three mangrove species under salinity stresses" (horticulturae-3440307). Your study certainly presents elements of interest and novelty. After carefully reviewing the updated version, I appreciate the revisions and additions you've made.

I would like to thank you for taking my suggestions into account.

Kind regards,

Reviewer

Response 1: We are extremely grateful for your kind words and the time you have dedicated to reviewing our manuscript. Your feedback has been instrumental in shaping the current version, and we are delighted to hear that you appreciate the revisions and additions we've made. It is encouraging to know that our efforts to address your suggestions have been successful. Your suggestions not only improved the quality of our manuscript but also deepened our understanding of the research topic.

Reviewer 2 Report (New Reviewer)

Comments and Suggestions for Authors

The Authors basically made reasonable corrections in the text of the Manuscript in the title and in the abstract which make it survivable.

The present Reviewer completely disagree that the measured electrical parameters somehow reflect "intracellular water-salt transport 111 and cellular metabolic energy based on the Gibbs Free Energy equation and Nernst 112 equation"; this assumption is completely not correct since the electrical parameters measured cannot be translated to chemical energy. The measured electrical parameters reflect the redistribution of water and gas phases in the complex multicellular system of leaves under pressure. However, the measured number of parameters is sufficient for publication. Therefore, the Reviewer leaves the references to energy and the calculations to the Editor of the Manuscript. Unfortunately, the not correct assumptions had already been published in several journals with hopefully not so high IFs.

Still the Manuscript requires major revisions.

1) The growth conditions for plants (temperature, humidity, illumination) had not been described.

2) Each cell of a plant can be regarded as a concentric spherical capacitor. The diagram 169

The morphology of cells doesn't fit the model. Cells of leaves are not spherical, they have cell walls, they have inhomogeneous cytoplasm and vacuole. All the statements of the sort should be softened at least. Here is a rude simplifying approach from the point of simple physical models which do not fit the complex biological systems.

3) Results. LISPC/LIUSF decreased. The LISAC of the three mangrove plants at no saltwas 1.27,1.32, 276 and 1.70,24 times higher than that at 0.4 mol/L, and the LISPC at no salt treatment was 277 2.00,1.62 and 2.65 times higher than that at 0.4 mol/L treatment.

Please, correct the misprints.

4) Table 5. Cellular metabolic energy of leaves at each salinity treatment level.

Here and everywhere in the text: here is not the metabolic energy but an artificially measured parameter which is not related to cell metabolism and energy. Suggest to rename the parameter since here is the not correct interpretation of the results. Left for the Editor and the Journal.

5) Photosynthetic and gas exchange parameters together water potential with the selection of mangroves and their growth parameters are sufficient to have the Manuscript published in the Journal.

6) Furthermore, R. stylosa plants growing at no salt treatment level exhibited a clear- 465 lysignificantly higher photosynthetic capacity than those subjected to NaCl treatments, 466

The text has many misprints. Please, check.

7) Did the salinity treatment show any effects on plants and their leaves morphology?

Comments on the Quality of English Language

Could be improved but it's understandable.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

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.

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper written by Wang et al is entitled “Dynamic traits of intracellular water and salt based on electro-2 physiology and adaptations of three mangrove species under 3 salinity stresses”. Authors exposed mangrove plants to different salt concentrations and use an electrophysiological sensor to understand the effects of salt dilution, salt exclusion and salt accumulation of leaf water and salt metabolisms. I have many concerns about the physiological relevance of the regulation proposed by the authors.

1-The authors described in the introduction that mangrove species always suffer from salinity stresses, high osmotic pressure, and low osmotic potential in the inter-tidal zone, which easily leads to metabolic disorders, poor growth, and even death. Then, they select low, middle and high salt treatments. I found some inconsistencies in those salt treatments used by the authors since in Table 2, all the species have improved height at middle salt and some of them even at high salt treatments. Are these appropriate treatments for slat stress analysis? Additional growth indices and survival assays should be informative about this concern.

2- In the discussion, authors  exposed they proved that the adaptability of mangrove plants differed with different salt stress levels, and revealed the dynamic adaptive characteristics of the  three mangrove plants under four salt gradients. However, they did not contrast electrophysiological and photosynthetic parameters with plant growth, in order to conclude about plant adaptation. It is surprising that medium salt treatment closes stomata, reduces CO2 and photosynthesis but according to Table 2 plants improve growth.

3- Table 1 references are missing.

Comments on the Quality of English Language

4- English particularly on the Abstract must be improved. It also has typing errors, e.g. “0, 0.1 mol/L (low salinity)”

Author Response

1. The paper written by Wang et al is entitled “Dynamic traits of intracellular water and salt based on electro-2 physiology and adaptations of three mangrove species under 3 salinity stresses”. Authors exposed mangrove plants to different salt concentrations and use an electrophysiological sensor to understand the effects of salt dilution, salt exclusion and salt accumulation of leaf water and salt metabolisms. I have many concerns about the physiological relevance of the regulation proposed by the authors.

Response: Thanks for your valuable comments, we have carefully addressed all the concerns, hope to meet with the requirements of this journal.

2. The authors described in the introduction that mangrove species always suffer from salinity stresses, high osmotic pressure, and low osmotic potential in the inter-tidal zone, which easily leads to metabolic disorders, poor growth, and even death. Then, they select low, middle and high salt treatments. I found some inconsistencies in those salt treatments used by the authors since in Table 2, all the species have improved height at middle salt and some of them even at high salt treatments. Are these appropriate treatments for salt stress analysis? Additional growth indices and survival assays should be informative about this concern.

Response: Absolutely, the serious salt stress will always lead to metabolic disorders, poor growth, and even death in many plants. As reported in the previous research, the salt concentration that had a remarkable negative impact on mangrove plants was more than 30‰ (about 0.5 mol/L NaCl). We have added this sentence into the first paragraph of the Introduction section. And we are sorry for not clearly introducing the actually applied salinity level or conditions in this manuscript. In fact, in the current research in this manuscript, it was not appropriate to define the 0.4 mol/L NaCl treatment as high salinity. We originally planned to simulate the high tide, mid tied and low tide of the inter-tidal zone using 0.1 mol/L, 0.2 mol/L, and 0.4 mol/L NaCl treatment solutions. The three selected mangrove plants can widely survive in the mid and low tide zone. In order to correctly describe the salinity level and avoid misunderstanding, we have revised the low, medium and high salinity in the manuscript to be 0.1 mol/L, 0.2 mol/L, and 0.4 mol/L NaCl concentrations, respectively.

With regarding to the results presented in Table 2, the mangrove plants selected in this research actually belong to halophytes, they actually need a minimum level of salt for optimal functioning, they can widely survive in the mid and low tide zone. Therefore, the 0.2 mol/L or 0.4 mol/L NaCl treatments would benefit the growth of those halophytes (i.e., R. stylosa at 0.2 mol/L and 0.4 mol/L, K. candel and A. corniculatum at 0.2 mol/L), in fact, the ΔH of R. stylosa at 0.2 mol/L exhibited no clear difference compared to the value at 0.4 mol/L (Table 2). Besides, the variation of growth could be attributed to the unique adaptations and physiological mechanisms in these halophytes, such as specific ion transport and osmotic regulation. The corresponding discussion has been added into Part 4.1 of the revised manuscript.

Finally, taking your feedback into account, we have included additional data on cellular metabolic energy, which is directly usable by cells for metabolism and essential for sustaining life processes. This added information will help us better elucidate the observed phenomena.

3. In the discussion, authors  exposed they proved that the adaptability of mangrove plants differed with different salt stress levels, and revealed the dynamic adaptive characteristics of the  three mangrove plants under four salt gradients. However, they did not contrast electrophysiological and photosynthetic parameters with plant growth, in order to conclude about plant adaptation. It is surprising that medium salt treatment closes stomata, reduces CO2 and photosynthesis but according to Table 2 plants improve growth.

Response: Thanks for the reviewer’s useful comments. In the revised manuscript, we have improved the Discussion section. We have revised the corresponding parts to correctly interpret the mechanisms of resistance to salinity, by combining the electrophysiological and photosynthetic parameters with plant growth. Meanwhile, we have drawn connections between our findings and existing knowledge in the field, and incorporated relevant literatures to support our conclusions. With regarding to the results of photosynthetic parameters and growth at 0.2 mol/L NaCl concentration treatment, we've also explained the phenomenon and described the reasons in detail and made changes in the corresponding part of the revised manuscript.

“Furthermore, R. stylosa plants growing at no salt treatment level exhibited a clearly higher photosynthetic capacity compared to those subjected to NaCl treatments, which was attributed to the highly opening stomata and sufficient water supply. However, the halophytes including R. stylosa are always bound to a minimum level of salt for optimal functioning, the treatment solution without NaCl addition seemed to be a stress condition for the growth of R. stylosa plants. Although the energy which was converted from the photosynthetic products maintained a high level for the cellular metabolic activities of plants at no salt treatment, but these plants also needed to allocate some energy converting from photosynthetic products for resisting the stress condition at this treatment, which as a result decreased the part of photosynthetic products using for biomass accumulation and was not supporting for the increase of ∆H.”

“Therefore, we speculated that this treatment (0.2 mol/L) was the optimum salt concentration for the growth of K. candel in this study. In other words, moderate salinity can promote the growth of K. candel, similar to the effects observed in other halophytes.”

“However, the increase in salt concentration did not impact on the fundamental life activities of A. corniculatum leaves in utilizing light energy for the synthesis of organic matter.”

4. Table 1 references are missing.

Response: Sorry for our careless. The references for table 1 have been added into the corresponding Part 2.1.

5. English particularly on the Abstract must be improved. It also has typing errors, e.g. “0, 0.1 mol/L (low salinity)”.

Response: Thanks for the reviewer’s kind reminding. We have made modifications in the revised manuscript to correct those typing errors and improve the English.

Reviewer 2 Report

Comments and Suggestions for Authors

The species used are very common in mangrove studies as they are some of the dominant species in this environment. There are already studies like this from 1985 or after 2008, but the updated view of the electrophysiological characteristics at the cellular level is correct.

However, it is still an updated review of an article (2022) by the same research team from doi: 10.1080/15592324.2022.2073420. In this one with a few less species, but with a very similar structure. Even the graphics are the same but more modern.

Other works with the same species, and others similar, are more an analysis of physiological parameters, of oxidative and genetic stress, and perhaps not so much electrophysiological and at the level of the plasma membrane, which in the end reflects the physiological state of the plant and plays a key role in ion absorption, especially in salinity

Regarding the work, it is necessary to correct the concentration of NaCl 0M, replacing it with a name like No Salt or Control, but zero is not counted and therefore units cannot be put. This affects text as well as figures and legends. In section 3.1, the leaf water potential symbol is confused, Ψ_L is not correct in my opinion, at least I should put Ψ_Lw. This also affects Table 2

The results of the analyzes are given, and clearly the species Aegiceras corniculatum excludes salt, and is more effective compared to the other two, but considering the results of table 3 of LIWHC, it is not discussed whether these species of mangroves are bound to a minimum level of salt for optimal functioning. Perhaps they are species forced to a minimum of salinity like many other halophytes.

In general, the article needs a discussion of the results obtained and not long lists of values ​​in tables or supplementary material. It is necessary to go further into processes at the intercellular level of the mechanisms of salt dilution, exclusion or accumulation as adaptive mechanisms to salinity.

The final conclusion is not a conclusion.

Author Response

1. The species used are very common in mangrove studies as they are some of the dominant species in this environment. There are already studies like this from 1985 or after 2008, but the updated view of the electrophysiological characteristics at the cellular level is correct.

However, it is still an updated review of an article (2022) by the same research team from doi: 10.1080/15592324.2022.2073420. In this one with a few less species, but with a very similar structure. Even the graphics are the same but more modern.

Other works with the same species, and others similar, are more an analysis of physiological parameters, of oxidative and genetic stress, and perhaps not so much electrophysiological and at the level of the plasma membrane, which in the end reflects the physiological state of the plant and plays a key role in ion absorption, especially in salinity.

Response: Thanks for the reviewers’ valuable comments. It is very crucial to clearly explain the difference between the current research in this manuscript and our previous work in the article (doi: 10.1080/15592324.2022.2073420). Hence, we have revised the manuscript and pointed out the new findings of the current research.

Absolutely, a variety of adaptation mechanisms, including root salt exclusion and leaf salt secretion of those typical salt-tolerant plants (i.e., R. stylosa, K. candel, and A. corniculatum), have been determined. The current study mainly used the electrophysiological technique which has been described in the article by Ali Solangi et al., resulting in similar technical graphics (Figures 2 and 3).

However, in 2022, Ali Solangi et al. established the intracellular water utilization parameters and salt transfer parameters based on the inherent electrophysiological characteristics. These parameters reflected the water and salt status of Aegiceras corniculatum and Kandelia obovate plants at each treatment level, and could determine the salt-resistant capacities of plants subjected to rewatering and SNP treatments, which could be verified by the photosynthetic performance of those two plant species. Most importantly, the salt outflow capacity (C1), salt dilution capacity (C2), and salt ultrafiltration capacity (C3) were defined and used for quantitatively comparing the salt-resistance of Aegiceras corniculatum and Kandelia obovate plants under rewatering and SNP treatments. Therefore, the electrophysiological parameters had the potential to rapidly and accurately address the salt-resistant capacity of those mangrove plants, and were used for evaluating the application effect of rewatering and SNP on the Aegiceras corniculatum and Kandelia obovate plants. However, in the study by Ali Solangi et al., it was still unknown how could those mangrove plants exhibit the salt outflow, dilution and ultrafiltration effects, what was the role of the dynamics of water and salt transports in regulating the salt outflow, dilution and ultrafiltration effects in plant leaf cells?

In the current manuscript (horticulturae-3345006), we highlighted the dynamic process of the adaptation of mangrove plants with the increase of salt stress levels. As we know, the transmembrane of salt ions in plant is always coupled with water transport in many cases, the investigation just focusing on the ions transport through cell membrane or the water movement is difficult to comprehensively and timely explain the complex changes of intracellular salt concentration. Therefore, the synchronous characteristics of water and salt metabolism within cells were currently taken into consideration when studying the ion homeostatic strategies of mangrove plants. In addition, we also defined the metabolic energy of cells based on inductive and capacitive reactance. We analyzed the adaptation mechanisms and interspecific differences in salt tolerance from the perspective of intracellular water-salt and metabolic energy dynamic characteristics. We believe that these aspects, combined with the updated discussion and enhanced data analysis, make this manuscript a valuable addition to the existing literature and distinct from our previous work.

2. Regarding the work, it is necessary to correct the concentration of NaCl 0M, replacing it with a name like No Salt or Control, but zero is not counted and therefore units cannot be put. This affects text as well as figures and legends. In section 3.1, the leaf water potential symbol is confused, ΨLis not correct in my opinion, at least I should put ΨLw. This also affects Table 2.

Response: Thanks for the reviewer's good suggestion. We've made changes in all the corresponding parts of the revised manuscript.

3. The results of the analyzes are given, and clearly the species Aegiceras corniculatum excludes salt, and is more effective compared to the other two, but considering the results of table 3 of LIWHC, it is not discussed whether these species of mangroves are bound to a minimum level of salt for optimal functioning. Perhaps they are species forced to a minimum of salinity like many other halophytes.

Response: Thanks for the reviewer’s good suggestion. We've made changes in the revised manuscript.

“The ion transporters on the root cell membrane of R. stylosa might be activated at this treatment level. These proteins can specifically recognize and transport beneficial ions such as K+ and Ca2+, and reduce the absorption of Na+ to ensure that the intracellular ion concentration is at an appropriate level [39]. This ion balance strategy provides favorable conditions for maintaining normal photosynthesis and stem elongation of R. stylosa.”

“Furthermore, R. stylosa plants growing at no salt treatment level exhibited a clearly higher photosynthetic capacity compared to those subjected to NaCl treatments, which was attributed to the highly opening stomata and sufficient water supply. However, the halophytes including R. stylosa are always bound to a minimum level of salt for optimal functioning, the treatment solution without NaCl addition seemed to be a stress condition for the growth of R. stylosa plants. Although the energy which was converted from the photosynthetic products maintained a high level for the cellular metabolic activities of plants at no salt treatment, but these plants also needed to allocate some energy converting from photosynthetic products for resisting the stress condition at this treatment, which as a result decreased the part of photosynthetic products using for biomass accumulation and was not supporting for the increase of ∆H.”

“Therefore, we speculated that this treatment (0.2 mol/L) was the optimum salt concentration for the growth of K. candel in this study. In other words, moderate salinity can promote the growth of K. candel, similar to the effects observed in other halophytes [41, 42].”

“However, the increase in salt concentration did not impact on the fundamental life activities of A. corniculatum leaves in utilizing light energy for the synthesis of organic matter.”

4. In general, the article needs a discussion of the results obtained and not long lists of values ​​in tables or supplementary material. It is necessary to go further into processes at the intercellular level of the mechanisms of salt dilution, exclusion or accumulation as adaptive mechanisms to salinity.

Response: Thanks for the reviewer’s kind reminding. We have revised the corresponding parts in the revised manuscript in order to make the discussion of the results more in-depth, which was highlighted in the Discussion and Conclusion sections of the revised manuscript.

5. The final conclusion is not a conclusion.

Response: The Conclusion section has been revised and improved, it can be seen in the revised manuscript.