Figure 5.

Based on weighted gene co-expression network analysis (A) and Pearson correlation analysis (B), key structural genes and transcription factors involved in the accumulation of organic acids in peach fruit were identified. A model for the significant accumulation of organic acids in peach fruit from high-altitude peach-producing areas is proposed (C): the down-regulation of key genes in the synthesis pathway and the up-regulation of key genes in the degradation pathway of organic acids ultimately lead to the accumulation of organic acids in the fruit.