Figure 11.

MYB73 is involved in malic acid accumulation via regulating Ma1 expression in apple fruit. A) Expression levels of MYB73, Ma1α, Ma1,β and malic acid concentrations in response to rattle virus‐based overexpression of MYB73 in mature WT fruits. Viral vector IL60‐MYB73 was infiltrated into fruit for overexpression of MYB73, with empty vector (IL60) as control. B) Expression levels of MYB73, Ma1α, Ma1,β and malic acid concentrations in response to rattle virus‐based suppression of MYB73 in WT mature fruits. Mature fruits were infiltrated with A. tumefaciens harboring TRV‐MYB73 for silencing MYB73 expression, with an empty vector (TRV) as control. C) Expression levels of MYB73, Ma1α, Ma1β and malic acid concentrations in WT mature fruits in response to overexpression of MYB73 or suppression of Ma1 alone or in combination via infiltration of viral vectors, IL60‐MYB73 and TRV‐Ma1, alone or in combination into fruits, with empty vectors (IL60 and TRV) as control. Quantitative RT‐PCR was performed using gene‐specific primers (Table S3, Supporting Information), with actin as the internal reference gene, and the relative expression level of each gene was obtained using the ddCT method. Data are mean ± SE of five biological replicates with three fruits per replicate (three injection sites per fruit). * Represents significant differences using Student's t‐test at p < 0.05, ** Represents significant differences using Student's t‐test at p < 0.01. Different letters (a, b, c) indicate significant differences between groups using Tukey's HSD test at p < 0.05 after ANOVA.