PpMYB10.1 regulates peach fruit starch degradation by activating PpBAM2

Area of Science:

• Plant Biochemistry
• Fruit Ripening Physiology
• Molecular Genetics

Background:

• Starch degradation is vital for soluble sugar production, impacting fruit flavor during ripening.
• Alpha-amylases (AMYs) and beta-amylases (BAMs) are key enzymes in starch metabolism.

Purpose of the Study:

• To identify and characterize amylase genes (PpAMYs and PpBAMs) in peach.
• To investigate the roles of specific PpAMY and PpBAM genes in fruit ripening and starch degradation.
• To elucidate the regulatory mechanism of starch degradation involving transcription factors.

Main Methods:

• Gene identification and phylogenetic analysis of peach amylase genes.
• Gene expression analysis during fruit development and ripening.
• Transient overexpression assays in peach fruit and callus.
• Promoter interaction analysis for transcription factor PpMYB10.1.

Main Results:

• Identified 5 PpAMYs and 9 PpBAMs in peach, classified into distinct groups.
• PpAMY1, PpAMY5, and PpBAM2 expression increased during mid-to-late fruit development.
• Overexpression of PpBAM2 significantly reduced starch content.
• PpMYB10.1 transcription factor directly activated PpBAM2 expression and reduced starch content.

Conclusions:

• PpBAM2 plays a significant positive role in peach fruit starch degradation.
• PpMYB10.1 acts as an activator of PpBAM2, contributing to starch metabolism regulation during ripening.