Fig 1.
Work flow diagram showing the steps of the starch granule purification.
Mature rice endosperm were used as the starting materials for this experiment. The final products were the purified starch granules used for further experiments in this report.
Fig 2.
Image of purified starch granules and the intermediate products of purification.
A: I2 stain image of the purified starch granules. Microscope observation with 40 × amplification; B: Cross section image of rice endosperm viewed by SEM. 6k amplification; C: Large endosperm fragment image under SEM. 6k amplification; D: Endosperm fragment image under SEM. 6k amplification; E: Partially purified starch granule image under SEM, 6k amplification; F: The sediments of grounded endosperm image under SEM, 6k amplification; G-I: Purified starch granule image at different magnifications under SEM. G: 1 k amplification; H: 6k amplification; I: 24 k amplification.
Fig 3.
The pattern of starch granule proteins and total proteins of rice endosperm on SDS PAGE.
The proteins extracted from rice endosperm and rice starch granules using phenol extraction method were separated by 12% SDS-PAGE and visualized by Coomassie blue stain. M: Marker; T: Total proteins; G: Starch granule proteins.
Fig 4.
Western blot image of the starch granule proteome. Same amount of proteins (25 μg per lane) were loaded.
A: Western blot images with different antibodies. The anti-bodies used were for V-ATPase E, V-ATPase A, Anti-Rubisco, cFBPase (Agrisera, Sweden). T: Total proteins; G: Starch granule proteins. B: Western blot image of protein acetylation of endosperm and starch granule proteins. Antibodies for acetylated Lysine (ImmuneChem) were used for Western blots. The source of proteins is indicated on the top of the lane. M: Protein marker; T: Total proteins extracted from endosperm; G: Proteins extracted from starch granules.
Table 1.
GO Distribution of the Starch Granule Proteins.
Table 2.
Starch Synthesis and Related Proteins Identified in Starch Granules Proteome.
Fig 5.
Distribution of identified proteins based on their peptide counts.
A: Protein peptide count numbers vs numbers of proteins. The proteins identified with the same peptide counts were grouped together to obtain the protein numbers. X-axis: protein peptide counts; Y-axis: number of proteins. B: Peptide count percentage distribution of 40 proteins with highest peptide counts (excluding storage proteins) in the chloroplast/amyloplast (red) and other organelles (blue).
Fig 6.
KEGG pathways enriched in the starch granule proteome.
KEGG pathway enrichment analysis of starch granule proteome. The value of -log10 (Fisher's test p value) is shown.
Fig 7.
Proteins enriched in starch and sucrose metabolic pathways.
The enzymes marked with yellow and blue color are proteins enriched in rice starch granule proteome.