PpMYB14-SAHH1 Module Regulates Peach Fruit Softening Through Promoting Lignin Accumulation

Area of Science:

• Plant Biology
• Molecular Biology
• Biochemistry

Background:

• Fruit softening significantly impacts postharvest quality and storage duration in peaches (Prunus persica L.).
• Understanding the molecular mechanisms governing peach softening is crucial for developing strategies to maintain fruit quality.

Purpose of the Study:

• To investigate the function and regulatory network of S-adenosine-L-homocysteine hydrolase 1 (SAHH1) in postharvest peach softening.
• To identify key genes involved in maintaining fruit quality during storage.

Main Methods:

• Quantitative real-time PCR (qRT-PCR) to assess gene expression and correlation with firmness.
• Overexpression and silencing studies in peach, tomato, and apple callus to evaluate gene function.
• Bioinformatic analysis for protein properties and promoter analysis.
• Transcriptome analysis to identify enriched pathways.
• Yeast one-hybrid, dual-luciferase, and GUS assays to verify transcription factor binding and activation.

Main Results:

• PpSAHH1 expression positively correlated with peach firmness.
• PpSAHH1 overexpression delayed senescence, maintained firmness, and preserved cell membrane integrity in peaches.
• PpSAHH1 altered cell wall metabolism in apple callus, increasing cellulose, hemicellulose, and lignin while reducing pectin.
• The transcription factor PpMYB14 directly binds to the PpSAHH1 promoter and activates its transcription.
• PpMYB14 silencing in apple reduced total phenols and cell wall components, especially lignin.

Conclusions:

• The PpMYB14-SAHH1 module plays a critical role in inhibiting peach softening.
• This module coordinates signaling pathways and phenylpropanoid biosynthesis to promote lignin accumulation, thereby enhancing postharvest quality.
• The findings provide novel insights and potential targets for improving peach storage and quality.