Gene expression studies. Changes in the relative expression of genes involved in L-ascorbic acid (AsA) metabolism of ‘Ailsa Craig’ fruits at immature green (IG; 27DAP), mature green (MG; 39DAP), B-1 (41DAP), breaker (B; 42DAP), B + 1 (43DAP), and red (52DAP) stage. Ripening stages are expressed as Days After Pollination (DAP). qPCR values were normalized against the geometrical mean of the expression of CAC and PP2Acs. Results are presented as the mean of three biological (each of them consist of a pool of 3 samples of equivalent stage) and two technical replications ± SD. Genes have been divided into four groups based on their relative expression pattern during ripening: 1) increase with ripening (A, SlGMP3; B, SlDHAR2), 2) decrease with ripening (C, SlGMP1; D, SlGMP2; E, SlGME1; F, SlGME2; G, SlGPP1; H, SlGalDH; I, SlGLDH; J, SlDHAR1), 3) peak at MG stage (K, SlGGP2; L, SlGPP2; M, SlMDHAR2) and 4) peak at B-1 stage (N, SlGGP1; O, SlMDHAR1; P, SlMDHAR3). Different letters indicate significant differences (P < 0.05) between values based on Duncan's multiple-range-test in SAS.