Expression patterns of SlSR s in tomato ripening mutant fruit. Total RNA from the rin, Nor and Nr fruit at mature green (MG) and breaker equivalent stages was subjected to RT-qPCR analysis. Relative gene expression levels (highest value = 100%) are shown following normalization with actin transcript values. Error bars represent standard error of the mean. For each gene, different letters indicate significant differences among mean values (P value < 0.05; t-test). The analyses were repeated at least three times in three independent experiments.