Fig. 3.

Relative expression of the genes involved in the synthesis of HGA (homogentisate) through the SK pathway (A), and in the synthesis of PPP (phytyl pyrophosphate) through the recycling of free phytol (B) and MEP pathway (C) in the flavedo of non-covered (NC) and covered (C) fruits of Star Ruby grapefruit, at the covering time (CT), harvest (H) and during postharvest storage at 2 °C for up to 8 weeks. The genes analyzed were: TAT1 (tyrosine aminotransferase), HPPD (4-hydroxyphenylpyruvate dioxygenase), VTE5 (phytol kinase), VTE6 (phytyl-P kinase), DXS1 and DXS2 (1-deoxy-D-xylulose-5-phosphate synthase 1 and 2), GGPPS1 and GGPPS6 (geranylgeranyl pyrophosphate synthase 1 and 6) and GGDR (geranylgeranyl diphosphate reductase). An expression value of 1 was arbitrarily assigned to the values obtained in the flavedo of C fruit at harvest. The data are mean ± S.E of at least three replicates.