PpZAT10 inhibits PpTST1 expression to regulate sugar accumulation in peach (Prunus persica) fruit

Tonoplast sugar transporter (TST) is a critical gene that regulates the accumulation of soluble sugars in peach; however, its regulatory mechanisms remain unclear. In this study, we identified a C2H2 transcription factor, PpZAT10 using a yeast one-hybrid screening of PpTST1 promoter in peach. PpZAT10 is a nucleus-localized transcriptional inhibitor that directly binds to the promoter of PpTST1 and depress its expression. Overexpression of PpZAT10 in peach fruit inhibited sugar accumulation by reducing the expression of PpTST1, whereas RNAi of PpZAT10 increased sugar content in peach fruit. Moreover, PpZAT10 significantly inhibited the expression of sugar accumulation genes, including PpTMT2, PpSTP1 and PpSUT5. PpZAT10 expression was significantly reduced under drought treatment, suggesting its involvement in sugar regulation during drought stress. Collectively, our findings reveal a novel regulatory network controlling sugar accumulation mediated by PpZAT10, which may be valuable for regulating sugar content in peach fruit.