A Combinatorial TIR1-Aux/IAA Co-Receptor System for Peach Fruit Softening

Round 1

Reviewer 1 Report

This study offers a compelling investigation into the role of the TIR1-Aux/IAA co-receptor system in the softening of peach fruits. The authors successfully demonstrate the potential of lower auxin concentrations in mitigating the hardness of these isolated fruits. The breadth of methods employed - including yeast two-hybrid technology, bimolecular fluorescence complementary technology, and firefly luciferase complementation imaging assay - serve as strong evidence of the TIR1 and Aux/IAA interaction within peach fruits.

To further strengthen the paper, I propose the following recommendations:

In the Introduction, the authors give too many details about Aux/IAA genes in tomatoes. Considering the study's focus on peaches and the complete sequencing of the peach genome, I suggest reorienting this section towards information pertinent to peaches.

The selection of the artificial auxin, NAA, over the naturally occurring IAA in the physiological experiment that measures fruit firmness lacks clear justification. Understanding the rationale behind this preference would be beneficial. Furthermore, since IAA was utilized in the two-hybrid experiment, elucidating any unsuccessful attempts with IAA in the physiological experiment would be informative.

The statement on line 80 posits that "the regulation of auxin on peach fruit softening is concentration-dependent." This conclusion currently lacks adequate context for comprehension. A more thorough explanation within this paragraph would improve reader understanding.

In Figure 2b, please identify the stage of fruit development during which gene expression was recorded.

The choice to use different auxin concentrations in the two-hybrid system versus the physiological experiment needs clarification. A rationale for this decision would be enlightening.

An in-depth discussion of the implications of PpTIR1 overexpression on auxin signaling, as highlighted in line 369, is necessary. The paper should consider exploring the upregulation of IAA1, IAA5, and IAA9 genes (Figure 3), and whether this is indicative of a swift auxin response suggestive of increased auxin signaling. On the other hand, the downregulation of several ARF genes may point toward negative feedback regulation of auxin signaling.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

The reviewed paper shows important results for peach fruit softening. This paper is characterized by high research quality and high significance of content. 

I have a few suggestion and comments:

- Molecular part of the paper is very well presented, however my suggestion is to improve and explicitly describe the treatment  with auxins - in abstract (line 23) 'interaction depended on auxin type', M&M (line 95) 2 concentrations of NAA were selected,  in lines 169 and 181 - 100 uM IAA was mentioned but in the line 281 we can read about 50 uM IAA. It is difficult to follow the parts with auxin treatment. Why in some analyzes NAA was used, and in others - IAA? Why in this concentrations?

- Please add the information about statistics in M&M section and in the Figures description.

Author Response

Please see the attachment.

Author Response File: Author Response.docx