Grape berry plasma membrane proteome analysis and its differential expression during ripening

Area of Science:

• Plant Biology
• Biochemistry
• Molecular Biology

Background:

• Grape berry ripening involves complex physiological and biochemical changes.
• Plasma membranes (PMs) are crucial for cellular processes, but their protein composition during ripening is poorly understood.

Purpose of the Study:

• To characterize the plasma membrane proteome of Vitis vinifera cv. Cabernet Sauvignon berries during ripening.
• To identify key proteins involved in transport, metabolism, and signaling pathways.

Main Methods:

• Isolation of high-purity plasma membranes using two-phase partitioning.
• Two-dimensional electrophoresis (2-DE) and silver staining for protein separation.
• MALDI-TOF mass spectrometry for protein identification.

Main Results:

• 119 protein spots identified in pre-véraison PMs, with 62 putative PM proteins identified.
• Identified proteins include ATP synthase, ABC transporters, and GTP-binding proteins.
• Total PM protein content decreased during ripening; 12 proteins showed significant abundance changes.

Conclusions:

• This research provides the first comprehensive characterization of the grape berry plasma membrane proteome during ripening.
• Changes in protein abundance suggest dynamic regulation of transport, metabolism, and signaling pathways.
• Ubiquitin proteolysis and cytoskeleton proteins increased, while Zeatin O-glucosyltransferase peaked at véraison.