Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript Acosta et al., investigates the germination properties of seed from Zephyranthes tubispatha (Amaryllidaceae). The work focuses on the effect of light period and the high temperature, and their interaction. The main observation is, that increasing light period per day delays the germination. This effect is mediated equally by monochromatic red and blue light. Pre-incubation of the seeds at high temperature erases the delay. The authors measure some phytohormone levels and superoxide anions to speculate about their possible regulatory roles in the Z. tubispatha germination.

The germination control is a complex process with a strong adaptive role. Articles about germination control often strictly limited to one aspect, such as only temperature or only light condition. This reviewer welcome this manuscript to read about a different species, when the complex germination control is analyzed in the context of the local habitat, that is often missing from studies. There is still a lot to learn about Z. tubispatha germination, but this work is a good initiation for further experiments. Although the manuscript is well written, some improvement could enhance the clearance and help the readers to draw clear conclusions.

 

Major comments:

 

1. The authors draw too strong conclusion about the possible HIR response in the negative photoblastic phenotype. From the shown experiment we cannot conclude if it is an HIR. Other experiments, such as light pulse experiments, and far-red treatments would be needed to conclude this. By definition, the HIR is induced by continuous light and not by light pulses. If intermittent light treatment with the same total fluence does not induce the same response, then it is an HIR. I suggest to remove the HIR from the conclusion. 

 

2. The experimental setup is often unclear, for example at Figure 4 and 5. I strongly suggest to include a schematic representation with simple drawings, that which treatment how long was applied, and from when the germination was counted. It is particularly true for the Figure 5, when this reviewer failed to understand what does 72 hours mean in t25 context?

 

3. Among bioactive gibberellins, the GA3 is known to regulate stem elongation, while GA4 and GA7-isolactone is effective in the germination control. Please see the publication: Gibberellins in seeds of Arabidopsis thaliana: biological activities, identification and effects of light and chilling on endogenous levels (Derkx et al., 1994 Plant Growth Regulation 15:223-234.) Therefore, the measurement of GA3 is not so informative, and it can be very misleading. It might be advisable to leave it out, or if possible, analyze GA4 instead.

The authors conclude, that the germination does not merely correlated with the absolute levels of phytohormones (line299). Yes, it is well known, that the GA:ABA ratio, rather than the absolute values control germination. Therefore, it is better to compare the hormonal ratio in the treatments, calculating in molarity and not in ng/g.

 

4. An additional conclusive sentences at the end of result parts 3.3 and 3.4 would help the readers to understand the message of the experiment, similar to 3.1 and 3.2.

 

Minor comments:

 

1. Please double-check the journal’s policy about “unpublished data” and “data not shown”. Nowadays most journals are strongly against the usage of these.

2. Line 149: Please add if preincubation means dry or wet treatment?

3. Figure 4: I would place the dry samples at the beginning. As written before, the treatments and their indication is very unclear.

4. Line 492-493: Is this sentence needed here?

5. Line 593: Is the name Herrranz correct?

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript presents a detailed investigation into the effects of light exposure and high temperatures on seed germination dynamics in Zephyranthes tubispatha, with a focus on the physiological mechanisms underlying photoinhibition and thermoinhibition. The study contributes valuable insights into the interplay between light and temperature cues in regulating seed germination and highlights the role of phytohormones such as ABA and ethylene in this process. I suggested that the authors conduct the following revision before acceptance.

1. The introduction provides a good background on the species but could benefit from clearer articulation of the specific research gap being addressed. The transition between previous studies on light and temperature cues and the novelty of this research is somewhat abrupt. A clearer explanation of why this specific study is needed would strengthen the introduction.
2. While the results suggest that Zephyranthes tubispatha seeds exhibit negative photoblastism and photoinhibition, the discussion could further elaborate on how these findings compare with other species known for similar responses. Additionally, there is limited discussion of the ecological relevance of photoinhibition in this species. The manuscript could benefit from a broader ecological perspective on how these responses might help the species avoid germination under unfavorable conditions (e.g., during dry, high-temperature periods).
3. The authors suggest that the HIR (High Irradiance Response) type of photoinhibition is responsible, but this could be further supported with references to other species showing similar responses. Additionally, more detail could be provided on the role of phytochrome in this response, including any related gene expression studies if available.

Author Response

Please see the attachment

Author Response File: Author Response.pdf