Wheat proteomics: relationship between fine chromosome deletion and protein expression

Area of Science:

• Plant genetics and molecular biology
• Proteomics and bioinformatics
• Agricultural science and crop improvement

Background:

• Understanding the relationship between chromosome structure and protein expression is crucial for wheat breeding.
• Previous methods like two-dimensional gel electrophoresis (2-DE) faced challenges in identifying specific wheat seed proteins due to complex genomes.

Purpose of the Study:

• To investigate the impact of fine chromosome 1B deletions on wheat seed proteome composition.
• To identify specific wheat seed proteins and their gene locations on chromosome 1B.
• To evaluate a novel analytical approach for protein identification and expression analysis in wheat.

Main Methods:

• Generation of fine deletion lines of common wheat using a monosomic alien chromosome addition line.
• Separation and visualization of endosperm and embryo proteins using two-dimensional gel electrophoresis (2-DE).
• Application of isotope-coded affinity tag (ICAT) labeling followed by electrospray ionization mass spectrometry (ESI-MS) for peptide analysis.

Main Results:

• Fine gene locations for several endosperm and embryo proteins on chromosome 1B were identified for the first time.
• ICAT labeling and mass spectrometry identified changes in peptide expression (4 down-regulated, 9 up-regulated) due to terminal deletion of chromosome 1B.
• Four proteins were successfully identified: alpha-amylase inhibitor, alpha-amylase/subtilisin inhibitor precursor, proteasome subunit alpha-type 7, and 1,4 alpha-glucan-D-maltohydrolase.

Conclusions:

• The identified proteins with specific gene locations can serve as valuable protein markers in wheat breeding programs for enhancing protein quality.
• The ICAT labeling coupled with mass spectrometry provides a feasible and effective approach for identifying wheat seed proteins and understanding their expression, overcoming limitations of 2-DE.