Figure 6.

Expression profiles of all 23 PpIAA genes during development of ‘Okubo’ and ‘Jing Yu’ peach fruits. RNA was isolated from peach mesocarp at different development stages and was analyzed by qRT-PCR. The horizontal axes indicate stages of fruit development: S1, cell division and enlargement; S2, period of slow growth (pit hardening stage); S3, second period of exponential growth; and S4, the physiological maturity stage, which can be further divided into three stages (S4-1, S4-2, S4-3). Similar expression patterns of genes were divided into four groups: (A) the genes were more highly expressed in ‘Okubo’ than in ‘Jing Yu’ in almost all development stages; (B) the genes more highly expressed in the stony hard cultivar during ripening stages; (C) the genes that displayed lower expression level in all fruit developmental stages and the expression of genes were significantly different in S2 between two cultivar; (D) the expression of gene was not significantly different between the two cultivars at any stage. All samples were run in triplicate. Error bars represent the SE of three independent biological replicates. Asterisks indicate statistically significant differences as determined by a Student’s t-test (* p < 0.05, ** p < 0.01).