All reviews of published articles are made public. This includes manuscript files, peer review comments, author rebuttals and revised materials. Note: This was optional for articles submitted before 13 February 2023.
Peer reviewers are encouraged (but not required) to provide their names to the authors when submitting their peer review. If they agree to provide their name, then their personal profile page will reflect a public acknowledgment that they performed a review (even if the article is rejected). If the article is accepted, then reviewers who provided their name will be associated with the article itself.
I confirm that the authors addressed all the Reviewers' comments. Consequently, the manuscript was significantly improved and the content is suitable for publication in this journal.
[# PeerJ Staff Note - this decision was reviewed and approved by Konstantinos Kormas, a PeerJ Section Editor covering this Section #]
Four Reviewers assessed your manuscript and found merit in its content. Several observations need attention; in particular those related to the experimental design, figures improvement, and biological significance of the results. Please prepare a revised version for a second round of revisions.
[# PeerJ Staff Note: The review process has identified that the English language must be improved. PeerJ can provide language editing services if you wish - please contact us at [email protected] for pricing (be sure to provide your manuscript number and title). Your revision deadline is always extended while you undergo language editing. #]
I consider that the article complies with the authors' guide and is duly written.
Very well
No comment
Correct in the line "364 pigmentation on the edges" (Liaquat et al., 2020)·
The manuscript is overall well written, but a few grammar details are encouraged to be corrected. The authors follow a reasonable structure and flow of their findings. Although data is sufficient for the topic, authors need to articulate and discuss possible reasons for differences between species, treatment, and timing, few data are not considered within the discussion (e.g. MDA index at 144 h).
How much inoculum of Trichoderma spp. (CFU) did you add to liquid media with either HM or control? Need this information to reproduce the experiment. Clarify in lines 122-123.
In lines 365 to 367 “Mycelial pigmentation is a characteristic that could be related to the tolerance of metals (Martino et al., 2000), and we suggest that pigment production could be related to the tolerance of T. asperellum and T. longibrachiatum to Cu, Cr, and Pb”.
However, there is no suggestion on how this correlates with their data (e.g. HM+Trichoderma sp gives xx color) and how this color correlates to a specific variable. Besides, there is no particular pigmentation in T. longibrachiatum for any of the HM.
The authors don´t discuss about Cr effect on dry mass and TI increase in T. longibrachiatum.
In lines 369 to 372 “T. longibrachiatum, hexaketide metabolites such as sorbicillinoids have been identified (Meng et al., 2016), and in T. asperellum, polyketides have been identified (Wu et al., 2017). However, the role of polyketides in tolerance to HMs in these two Trichoderma species has not been studied and could be the subject of future studies." It is not clear how this is relevant and how it links to the authors findings related to pigmentation and TI.
In figure 3 and 4, wonder whether GPX and CYS differential expression between Trichoderma species would be similar among different strains within the same species.
I suggest an overall review of grammar issues. Overall the article has the quality to be published once the authors go through the comments and revisions.
This research shows the possible damage caused by heavy metals generated by anthropogenic activities, which can harm soil microbial communities, especially fungi of the Trichoderma genus.
Overall, the work is carried out correctly and shows the raw data. The methods used help to resolve the hypothesis raised.
Why was 100 mg of each of the heavy metals used in this research? Is there any precedent that indicates the gradual increase or concentration of these contaminants in soils?
I think it is necessary to further substantiate this point.
The conclusions reached by the research work are supported by the results shown in the manuscript.
Line 25: This is the first time these microorganisms' names appear in the manuscript, so you must include the full name.
Line 85: Full name of Trichoderma asperellum.
Line 87: Full name of T.lixii
Line 91: Full name of T. harzianum
Line 96: Full name of T. longibrachiatum
Line 95: Define the gene GPX, CAT and CYS.
Line: 111: From now on, you can abbreviate T. asperellum and the others mentioned above.
Line 134: Briefly describe the protocol used.
Line 181: H2O2 ; what concentration or percentage?
Fig 1. In the legend at the bottom of the figure, change the word sporulation to conidiation; since they are not spores, the same for panel C. And also in the supplementary data found on the excel page.
Fig. 3. In panel b; In the case of Pb and Cr, why was this difference not evaluated? They are not significant?
And in panel e). Why are they no longer expressed with Cu, Pb and Cr? Why does this happen?
Lines 252-349: These lines have some repetitions about the traits of fungal strains when placed in the presence of metal. You could mention it once.
Line 362: Full name of T. virens
Line 367: Full name of T. reuse
Line 374: conidia nor spore
Line 379: Full name of T. viride
Line 380: Full name of T. gamsii
line 398: Full name of P. opuntia.
Line 418: What kind of plant is it?
Nothing is in the literature about the CAT gene of fungi and heavy metals.
An experiment that I consider important is about the viability of the conidia of both strains when they are exposed to heavy metals. Especially because there is variation in production when they are challenged with metals. This result would be important in concluding that heavy metals reduce the fungal community (Trichoderma) of the soil in which these contaminants are found.
In line 115, they mention that they use the conidia for growth in the face of metals, but after exposure, are the ones that have been produced viable?
I consider important to justify why to do the analysis on mycelium/ conidia (different morphologies) and not on chlamydospores, in some of the introduction or materials/methods sections, what information each one provides. It is mentioned a little in line 361, but I consider important to explain this point.
In the materials/methods section describe how the tolerance index was performed, normally what is performed is the measurement of the mycelial radius of the fungus with metal/ fungus without metal, but here how was it performed if it is mentioned that it forms aggregates?
How were the conidia recovered from the liquid medium, was any viability analysis for conidia performed?
In line 126 it is mentioned that images of liquid medium cultures were taken, but the images shown in Figure 1 are liquid medium cultures, describe what is observed in the cultures or include the photographs.
In Figure 1, consider placing microscopy images to observe the aggregation of the fungus.
In Figures 3 and 4, the legends of the graphs I consider that “Relative expression levels” should be placed, since in the figure caption they indicate that the data were normalized with the TUB gene. I believe that “Relative expression levels” should be placed in the figure caption to indicate that the data were normalized with the TUB gene.
There are already studies of T. harzianum and T. virens with these same heavy metals, what is the biological importance of T. longibrachiatum and T. asperellum to perform the studies in these models? I consider that this point should be explained so that the objective of the study is clearer
no comment
All text and materials provided via this peer-review history page are made available under a Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.