Impacts of Cd on Temporal Dynamics of Nutrient Distribution Pattern of Bletilla striata, a Traditional Chinese Medicine Plant
Round 1
Reviewer 1 Report
“Impacts of Cd on Temporal dynamics of nutrient distribution pattern of Bletilla striata, a traditional Chinese medicine plant”
The objective of the work submitted for the review was to determine the relationship between the degree of soil Cd concentration and its content in the study species Bletilla striata, the effects of Cd contents on plant parts development (leaves, shoots, tubers, and roots) and the relation between nutrient allocation and Cd plant enrichment. B. striata is an important Chinese medicinal plant but endangered due to limited natural wild resources. Currently, artificial cultivation of B. striata is being developed. The study of the effects of heavy metals on plant development is a widely studied issue in the context of crop plants, especially monoculture crops that provide nutritional security in all countries of the world. Less popular, however, is the study of plants in natural environments, often under protection, including those that have applications in natural medicine. Therefore, the research presented in the submitted manuscript is important especially in these days when more and more wild natural areas are under human pressure. The authors, considering the diverse reports on the effects of Cd on plant development, presented 2-year results of an important Chinese medicinal plant Bletilla striata and attempted to elucidate the effects of different Cd concentrations on plant development and its defense mechanisms. The effect of varying Cd concentrations in Bletilla striata pot cultivation on the plant development and nutrient allocation has not been studied before. I have a few comments:
- Figure 1 shows that under short-term Cd exposure (T1), dry weight of leaves, shoots, and roots increased slightly at all Cd concentrations. In the second year (T2), dry mass also increased in all parts of the Cd-treated plants, although the least increase in leaf, shoot, and tuber mass occurred at Cd concentration IV, except for the roots, whose biomass decreased at Cd concentration IV. Explain why you write that the biomass of leaves and shoot, tuber, root decreased at high Cd concentrations (7.39 and 54.6 mg/kg) at T2 (line 149-150).
- Figure 3: Correct the marking in position IV Cd treatment in T2-9.
- The effect of cadmium addition on Zn content in B. striata was not so simple. In the first year (T1), Zn content increased from T1-7 to T1-9 regardless of Cd concentration and part of plant. However, in the next year (T2), Zn content was at a significantly lower level at T2-7 compared to T1-9 and gradually increased. Could you explain why Zn content decreased after T1-9 and was at a significantly lower level at T2-7 (Line 191-193).
- Table 1: Use a subscript for the letter k in the abbreviation TFk1 and correct the abbreviation TFk2 and TFc2 (use high letter).
- Comments on individual lines:
Line 23: The symbol T2-9 is illegible in the Abstract, it should be removed.
Line 37and 124: Reichb. f. change to Rchb. f.
Line 133: screened change to screened out.
Line 148: complete (T1) at the sentence: „Under short-term (T1)…
Line 160: Explain the abbreviation DW.
Line 160: The max Cd accumulation is amounts to 772.2 μg - T2-8 (Table S1).
Line 180: K content in shoots and roots decreased at T1 and T2-7 compare to control (Table S2).
Line 197-198: The tubers demonstrated the highest Zn accumulation at a Cd dose of 1.00 mg/kg (II) in the first year (T1) and at a Cd dose of 0.37 mg/kg (I) in the second year (T2), except T2-7 (if it is possible try to explain). The high Cd dose (54.6mg/kg) significantly reduced Zn accumulation compared to the control only in the second year (T2) (Table S6).
Line 241-251: This paragraph should be included in the Introduction.
Line 272-273: Insert this sentence in the previous paragraph.
Line 269-272 and 276-277: Rephrase and combine these sentences.
Line 278: Insert only year in the bracket.
Line 280: Explain the ZIP abbreviation.
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Comments – “Impacts of Cd on Temporal dynamics of nutrient distribution 2 pattern of Bletilla striata, a traditional Chinese medicine plant”.
Agriculture 2021, 11, x. https://doi.org/10.3390/xxxxx
The problem of soil contamination may be of great importance for crops grown, e.g. in the vicinity of heavy industrial sites. Heavy metals, their bioaccumulation in food chains pose a direct threat to wildlife and human health. Therefore, the problem presented in the submitted paper: Cd content, growth and mineral nutrient uptake and transfer in Bletilla striata are interesting and of broad international interest. The paper falls within the Aims and Scope of the journal. This article contains new aspects and is of general interest. The presentation reflects the present state of knowledge. The paper has an appropriate structure. However, I have only some suggestion to improve the manuscript:
The goal of the study is too general. In my opinion, it should be rewritten in a more particular way.
Material and methods:
Where the research were performed? That was a pot experiment - how many plants were grown in each pot? How many composite/single samples have been taken under consideration?. How many analytical replications in heavy metals estimation were taken under consideration. Statistical analysis must have biological replicates, and therefore, it should be precisely specified. What about the certified reference material in estimated elements analysis?
The uptake of metals depends on the bioavailability of metals. What about bioavailable Cd concentration in the studied soil and pH value?
The figures miss information about the statistically significant differences (e.g. using symbols in superscript) between obtained values in all experiments treatment.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
