Fig. 4

Spatiotemporal patterns of asparagine (Asn) concentration and transcript abundance of Asn metabolism-related genes in apple fruit tissues in response to fruit load reduction. Fruit load reduction was performed at 11 d after full bloom. Asparagine concentration was determined using gas chromatography and transcript abundance was determined using quantitative RT-PCR. Mean and S.D. (n = 4) are displayed for metabolite data. Mean and S.E. of the mean are displayed for transcript abundance data (n = 4). CC: Control fruit load-Cortex; CP: Control fruit load-Pith; RC: Reduced fruit load-Cortex; RP: Reduced fruit load-Pith. ASPA: ASPARAGINASE; GS: GLUTAMINE SYNTHETASE. All transcript abundance data are in reference to mean expression at 0 d after treatment in RC. Apple ACTIN and GAPDH (GLYCERALDEHYDE 3-PHOSPHATE DEHYDROGENASE) genes were used for normalization of transcript abundance data. Asterisk and dagger symbols indicate significant difference between control and reduced fruit load treatments in the cortex and pith, respectively (α = 0.05). Shaded regions indicate early (dark grey), mid (light grey), and late fruit development (white) periods