Physiological and Biochemical Responses of Kandelia obovata to Upwelling Stress
Round 1
Reviewer 1 Report
The work of Li et al fits well in the scope of the journal.
Main criticisms:
- Abstract: please do not assume a change in the activity of enzymatic antioxidants, since this is not clear from the results. You should only mention increasing tendency in SOD and decreasing tendency in CAT)
- Please clearly justify the conditions selected for simulating upwelling (only changes in Temperature when this is only one (among others) relevant parameters involved? and why 13ºC and 5 ºC ?). You may also use some references to consolidate your choices.
- 2.1 Please further detail the plant material (fresh?)
- in the discussion section, the comparison with additional studies focusing on the impact of upwelling would be advisable.
Author Response
Point 1: Abstract: please do not assume a change in the activity of enzymatic antioxidants, since this is not clear from the results. You should only mention increasing tendency in SOD and decreasing tendency in CAT.
Response 1: We gratefully appreciate for your valuable suggestions. We’ve made some revision in the abstract in manuscript and as shown below:
“Line 23-25: Further, the activities of antioxidant enzymes, such as superoxide dismutase activity (SOD) and peroxidase activity (POD) showed an increasing trend during the treatment while catalase activity (CAT) were on the contrary.”
Point 2: Please clearly justify the conditions selected for simulating upwelling (only changes in Temperature when this is only one (among others) relevant parameters involved? and why 13ºC and 5 ºC ?). You may also use some references to consolidate your choices.
Response 2: Thanks for your valuable suggestion. Upwelling activities do produce changes in several parameters, but the most obvious change is temperature. Besides, temperature plays an important role in plants growth and development. As a result, our study focuses more on the air-water temperature difference caused by upwelling.
Considering the previous studies on low temperature tolerance of Kandelia obovata, we selected 5 °C and 13 °C as the treatment temperature. On the one hand, K. obovata is regarded as one of the most cold-tolerant mangrove species and has a strong tolerance to temperature above zero(Jiao Fei, 2021; Wen-Xun Lu, 2021; Ya-lan Peng, 2015). On the other hand, based on the purpose of laboratory simulation, we hope to observe more obvious changes in physiology and biochemistry of K. obovata under upwelling treatment.
Point 3: Please further detail the plant material (fresh?)
Response 3: Thanks for your valuable suggestion. We’ve made some revision in manuscript and as shown below:
Plant material:
“Line 97-101: Following one month of acclimation in Hoagland nutrient solution, K. obovata seedlings were divided into three groups while each group contains 10 seedlings. The second pair of fresh leaves was taken as the measurement material for each index and three bio-logical replicates were guaranteed.”
Point 4: in the discussion section, the comparison with additional studies focusing on the impact of upwelling would be advisable.
Response 4: Thanks for the above suggestion and we have been actively looking for the reasonable comparison studies. However, we can barely find the research about the physiological and biochemical effects of upwelling on plants. Therefore, we pay more attention to the impact of low temperature on plants, and find out the unique response mechanism of mangrove to upwelling with comparison.
Jiao Fei, Y.-S. W., Hao Cheng, Fu-Lin Sun, Cui-Ci Sun. (2021). Comparative physiological and proteomic analyses of mangrove plant Kandelia obovata under cold stress. Ecotoxicology, 30(9), 1826-1840. doi:10.1007/s10646-021-02483-6
Wen-Xun Lu, B.-H. Z., Yuan-Ye Zhang, Sheng-Chang Yang. (2021). Differentiation of Cold Tolerance in an Artificial Population of a Mangrove Species, Kandelia obovata, Is Associated With Geographic Origins. Front Plant Sci, 12, 695746. doi:10.3389/fpls.2021.695746
Ya-lan Peng, Y.-s. W., Jiao Fei, Cui-ci Sun, Hao Cheng. (2015). Ecophysiological differences between three mangrove seedlings (Kandelia obovata, Aegiceras corniculatum, and Avicennia marina) exposed to chilling stress. Ecotoxicology, 24(7-8), 1722-1732. doi:10.1007/s10646-015-1488-7
Reviewer 2 Report
This manuscript is an interesting study on the physiological and biochemical responses of Kandelia obovata to upwelling stress. The main section is well structured and derives logically from the results obtained. The presentation is clear, however, information on the number of seedlings/leaves per group/replicate is lacking in the methods description. Such information is an important element to assess the experimental design and to verify whether dataset is sufficient for evaluating variation in measurements under conditions of reproducibility.
In Table 1, eigenvalues of all variables analyzed (but only of the first three Principal Components -PC) must be included, since they accounted almost for 80% of total variation. Please, delete the other components.
I do recommend to consider other data analysis method to complement and built a most robust statistical approach. Mixed-effects models (GLMM) can be an alternative for this case. This approach provides a broad range of models for grouped data. Authors can use these models to test for i) differences between the functional traits of the groups and ii) the relationship between these functional traits. Afterwards, the authors should interactively rearrange the results and discussion of the manuscript following the new statistical approach. In this case, manuscript need some work, but it should be adjusted in accordance with the new results.
Author Response
Response to Reviewer 2 Comments
Point 1: This manuscript is an interesting study on the physiological and biochemical responses of Kandelia obovata to upwelling stress. The main section is well structured and derives logically from the results obtained. The presentation is clear, however, information on the number of seedlings/leaves per group/replicate is lacking in the methods description. Such information is an important element to assess the experimental design and to verify whether dataset is sufficient for evaluating variation in measurements under conditions of reproducibility
Response 1: Thanks for your valuable suggestion. We’ve made some revision in the methods in manuscript and as shown below:
“Line 97-101: Following one month of acclimation in Hoagland nutrient solution, K. obovata seedlings were divided into three groups while each group contains 10 seedlings. The second pair of fresh leaves was taken as the measurement material for each index and three bio-logical replicates were guaranteed.”
Point 2: In Table 1, eigenvalues of all variables analyzed (but only of the first three Principal Components -PC) must be included, since they accounted almost for 80% of total variation. Please, delete the other components.
Response 2: Thanks for your valuable suggestion. We’ve deleted the other components in table 2.
Table 2. Principal component analysis eigen values for response indexes of K.obovata seedlings under upwelling.
|
PC1 |
PC2 |
PC3 |
|
|
Eigenvalue |
6.700 |
2.541 |
1.875 |
|
Proportion % |
47.86 |
18.15 |
13.39 |
|
Cumulative % |
47.86 |
66.01 |
79.4 |
Point 3: I do recommend to consider other data analysis method to complement and built a most robust statistical approach. Mixed-effects models (GLMM) can be an alternative for this case. This approach provides a broad range of models for grouped data. Authors can use these models to test for i) differences between the functional traits of the groups and ii) the relationship between these functional traits. Afterwards, the authors should interactively rearrange the results and discussion of the manuscript following the new statistical approach. In this case, manuscript need some work, but it should be adjusted in accordance with the new results.
Response 3: We are really appreciated for your valuable suggestion. We have studied the mixed-effects models to some extend and this method do have a great help for our analysis. However, we have carefully evaluated the experiment data and time and found that such modification is not currently affordable. Meanwhile, we feel that the PCA still plays an important role in our present paper. Therefor, we suggest the data analysis models be included in a follow-up paper.
Reviewer 3 Report
The paper is interesting, however it needs improvement before its final acceptance. First of all, an English language revision is necessary. Moreover, introduction section should be reduced (for instance the paragraph from l.50 to l.76 should be significantly shorter) while overall there is an inadequate justification of the aims and objectives of this study. Some indicative comments can be also found below.
l. 19: revealed (instead of found)
l. 143: K. obovata italics
l. 201: Previous studies
l. 90: treatments (not treatment conditions)
l. 215-216: The value of Y(â…¡), ETR and qP values showed a decrease compared to control but no significant change: when the differences are not statistically significant then there are no differences and should not be mentioned
l. 310: further study (instead of further research)
Author Response
Response to Reviewer 3 Comments
Point 1: The paper is interesting, however it needs improvement before its final acceptance. First of all, an English language revision is necessary. Moreover, introduction section should be reduced (for instance the paragraph from l.50 to l.76 should be significantly shorter) while overall there is an inadequate justification of the aims and objectives of this study. Some indicative comments can be also found below.
- 19: revealed (instead of found)
- 143: K. obovata italics
- 201: Previous studies
- 90: treatments (not treatment conditions)
- 310: further study (instead of further research)
Response 1: Thanks for your careful check and valuable suggestion. We have carefully checked the manuscript and made corrections to English grammar and writing errors. We have also revised the introduction section to make it more streamlined and justification and all the comments you gave above have made relevant revision in the manuscript.
Point2: l. 215-216: The value of Y(â…¡), ETR and qP values showed a decrease compared to control but no significant change: when the differences are not statistically significant then there are no differences and should not be mentioned.
Response 2: Thanks for your suggestion. Although there’s no statistically significance in Y(â…¡), ETR and qP values, they show the decreasing trend. And these had certain implication for our data analysis which demonstrated that the original light energy capture efficiency in the PS â…¡ reaction center decreased slightly but still maintained in a regular level. It helps us to better understanding the status of plants under upwelling.
Reviewer 4 Report
The paper is interesting and in my opinion it is well written, however, the whole experimental design is based on only nine plants (three plants per three treatments). I'm skeptical about the possibility of accepting a paper based on such a limited sample of plants. The authors must check the contracted forms of the references (eg Plant and Soil = Plant Soil) and write the species and genera in italic
Author Response
Response to Reviewer 4 Comments
Point 1: The paper is interesting and in my opinion it is well written, however, the whole experimental design is based on only nine plants (three plants per three treatments). I'm skeptical about the possibility of accepting a paper based on such a limited sample of plants. The authors must check the contracted forms of the references (eg Plant and Soil = Plant Soil) and write the species and genera in italic
Response 1: Thanks for your careful reading and valuable comments. We would apologize for not expressing ourselves clearly. We have revised the material and method section of the manuscript to better describe our experiment design.
“Line 97-101: Following one month of acclimation in Hoagland nutrient solution, K. obovata seedlings were divided into three groups while each group contains 10 seedlings. The second pair of fresh leaves was taken as the measurement material for each index and three bio-logical replicates were guaranteed.”
We have also carefully checked the references and made revision in the manuscript.
Round 2
Reviewer 4 Report
I accept the current version of the article because the authors have done the analyzes on thirty plants
