Changes in the mitochondrial proteome of developing maize seed embryos.

Area of Science:

• Plant Biology
• Mitochondrial Biology
• Seed Development

Background:

• Mitochondria are essential for seed development, but their specific functions during this process are not well understood.
• Understanding mitochondrial roles is crucial for improving seed viability and crop yield.

Purpose of the Study:

• To investigate the function and proteomic changes of mitochondria during maize embryo development.
• To create a comprehensive map of mitochondrial energy production during seed development.

Main Methods:

• Isolation of mitochondria from developing maize embryos.
• Analysis of mitochondrial membrane integrity, respiration, and proteome using two-dimensional gel electrophoresis (2-DE) and sequential windowed acquisition of all theoretical fragment ion mass spectra (SWATH).

Main Results:

• Mitochondrial membrane integrity and respiration remained high until 21 days after pollination (DAP), then declined.
• Mitochondrial number, cytochrome c oxidase activity, and respiration per embryo showed a bell-shaped curve, peaking at 35-45 DAP.
• 286 mitochondrial proteins changed abundance; early stages showed increased proteins for energy production and metabolism, while later stages showed increased stress and detoxification proteins.

Conclusions:

• Mitochondria are highly active in early maize embryo development, supporting rapid growth.
• In later stages, mitochondria become quiescent but are protected, aiding embryo maturation, drying, and storage.
• This study provides novel insights into the organelle-level mechanisms governing seed development.