Expression patterns of carotenoid-related genes during ripening of RHB and RH fruits. Relative average gene transcript levels ± SD are given, following normalization with rps28 values. A: isoprenoid genes [cmk, 4-(cytidine 5'-diphospho)-2-C-methyl-d-erythritol kinase; dxs, 1-deoxy-d-xylulose 5-phosphate synthase; hdr, 4-hydroxy-3-methylbut-2-enyl diphosphate reductase]. B: early carotenoid genes (pds, phytoene desaturase; psy, phytoene synthase; zds, ζ-carotene desaturase). C: other carotenoid genes (chy-b, carotene β-hydroxylase; chy-e, carotene ε-hydroxylase; lcy-b, lycopene β-cyclase; lcy-e, lycopene-e-cyclase; zep, zeaxanthin epoxidase). D: dioxygenase-related genes (ccd1 and ccd4, carotenoid cleavage dioxygenases 1 and 4; nced1 and nced2, 9-cis-epoxycarotenoid dioxygenases 1 and 2). For each gene, different letters indicate significant differences among mean values from different stages (*: p ≤ 0.05; **: p ≤ 0.01).