Fig. 1: Construction of the peach mAb library and screening of differentially expressed proteins in ripening peach fruit with a mAbArray chip.

a Peach protein antigens used to generate the mAb library. SDS-PAGE analysis of proteins extracted from peach fruit that were used as antigens for antibody library construction. Proteins were extracted from the mesocarp of the CN13 and CN16 cultivars at ripening stages S3, S4 I, S4 II, and S4 III. Twenty micrograms of protein was separated by SDS-PAGE and stained with Coomassie blue. b–d Quality of the antibody chip analyzed by hybridization. b Antibody chip after hybridization with Cy5-labeled goat anti-mouse IgG, and the Cy5 signal was scanned. c Magnified image of one block. The red circles and block indicate the positive controls (biotin-labeled BSA), and the green circles indicate the negative controls. d Diagram of mAb arrangement on the chip. e The peach mAbArray chip was used to screen for differentially expressed proteins in CN13 fruit between fruit-ripening stages S3 and S4 III. The differences in fluorescence intensities between peach fruit from stages S3 and S4 III within a small area of the chip are presented. f Correlation matrix of the replicated samples. g Volcano plot depicting the analysis of the differentially expressed proteins. The p value cut-off was 0.05 (y-axis), while the abundance fold-change cut-off was >1.5 or <−1.5 (x-axis). Significantly and nonsignificantly differentially expressed proteins are indicated in blue and red, respectively. h Western blot (WB) analysis of the differentially expressed proteins identified by LC-MS/MS. CN13 fruit samples harvested during stages S3 and S4 III were analyzed