Changes in Diversity and Community Composition of Root Endophytic Fungi Associated with Aristolochia chilensis along an Aridity Gradient in the Atacama Desert
and Marcia González-Teuber 1,*
Round 1
Reviewer 1 Report
The reviewed work entitled 'Changes in diversity and community composition of fungal endophytes associated with Aristolochia chilensis along an aridity gradient in the Atacama Desert' is a study of the diversity and community composition of fungal endophytes associated with Aristolochia chilensis. Authors found that richness indexes were inversely related to aridity, although this pattern was partially observed for FE frequency and diversity. FE community composition was dissimilar among contrasting locations, and soil water availability significantly influenced FE community composition across the gradient. Authors postulate that their data indicate that both long-term historical patterns of precipitations and current levels of soil water availability are relevant factors influencing FE distribution in desert ecosystems. I am not sure if they can speculate this based on their results, which haven't been actually shown. There are no repetitions of samples analysed. It is not known exactly how samples were taken from each location. In how many places etc.? There are actually no results from this part of the experiment. Why was only the 18S rDAN characteristic of fungi analyzed, and not the bacteria, which are also part of the FE? The results of edaphytic analyzes are also presented in the form of final values and it is difficult to say whether they were carried out correctly. The results obtained are largely in line with expectations and do not bring much new information. They can be presented in the form of a short report, and in order for them to become an original scientific article, it would certainly be appropriate to repeat, take samples in a specific area from several populations in one location. Carry out a thorough species analysis of the fungi and bacteria found there, not just fungi. > 265 - different - what does it mean? > 269 - small? > 280 - rDNA - why only for fungi > 281 - 2 ul of both primers would give 12 ul of PCR mixture. In my opinion, the work in its current version is not suitable for printing. It should be extended to include additional research. It adds little to the current state of knowledge.Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
Review article “Changes in diversity and community composition of fungal endophytes associated with Aristolochia chilensis along an aridity gradient in the Atacama Desert” written by Guevara-Araya et al.
The authors collected material of Aristolochia chilensis from three places along an aridity gradient in the coast of the Atacama Desert in Chile. They studied root- associated endophyte diversity and community composition linked to aridity. The authors also analyzed the role of edaphic factors co-varying with aridity (soil water potential, soil moisture, pH and nutrients) on structure of the belowground fungal endophyte communities. The authors expected that fungal endophyte diversity gradually increases towards the aridity declines and those locations having the most contrasting environments should show more dissimilar fungal endophyte communities. They found that richness indexes were inversely related to aridity, although this pattern was partially observed for fungal endophyte frequency and diversity. Additionally, they detected that the community composition was dissimilar among contrasting locations, and soil water availability significantly influenced the belowground fungal endophyte community composition across the aridity gradient studied.
Weaknesses of the manuscript, only 10 plants are included in the study for each of the three sites. I would expect for this type of study, at least 5 plots (replicates) for each site and each plot should include 5 to 10 plants. In addition, the co-occurring vegetation should be also considered. It is very difficult with such limited sampling to robustly test the hypothesis and objectives proposed in the study. Rather, the predictions could be that when the plant is under unfavourable conditions it should have a greater diversity of associates in order to be able to tolerate the stressful environmental conditions and thus these plants may survive specifically under very low water availability.
It is difficult to demonstrate with such limited sampling and using a single study methodology that the diversity and composition of endophytic fungi changes along a gradient.
Line 212 refers to frequency... or abundance?
Line 267 medium used not very suitable as it allows the isolation of fast growing fungi such as Penicillium, Fusarium, etc. This support my hypothesis that the low diversity found is rather due to methodological bias and does not necessarily correspond to the natural diversity present in the sites analysed. Therefore, any calculation of relative abundance is not valid. The authors should include within the main manuscript a table with all isolated and identified fungi.
Line 271 both genera are common root inhabitants of non-woody plants.
Line 269 the number of pieces per plant used to isolate fungi is not specified.
Line 291 does not indicate how OTUs were defined. The molecular part is very weak.
Line 315 no mention of how irrigation regimes were defined... why 85 mm3? and not another amount? For the reading public outside of Chile, it would be appropriate to include a map of the sampling sites, including plant pictures, etc.
Author Response
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Reviewer 3 Report
Obviously, only root endophyte fungi were studied. This should be reflected in the title of the paper and in other appropriate places. The results description is very short. In this case, one could merge the Results and Discussion sections.
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Please, change μl on molar quantities in this text: 'Partial amplification of the 18S rDNA gene (about 680 kpb) was performed with 10 μl of PCR reaction mixtures, each with 3 μl fungus genomic DNA, 1 μl of each primer, 3 μl of SapphireAmp Fast PCR Master Mix (Takara) and 2 μl of sterile water. You cant use microlitres in scientific text. 20-40 ng of DNA?, 10pM of primers ? 1 x Mix? and not mention water quantity.
Author Response
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Author Response File: 
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Reviewer 3 Report
The authors have sufficiently improved their manuscript, so it can be potentially published. The need to merge the Results and Discussion sections I leave at the discretion of the academic editor.
Author Response
- The guidelines made by the journal states that Results is a different section from the Discussion. We, additionally, consider that the Results section in our manuscript is not too short to be merged with the Discussion section.
- The text has been reviewed by a native English speaker.
