Transcription of potassium transporter genes of KT/HAK/KUP family in peach seedlings and responses to abiotic stresses

Potassium uptake and transport is facilitated by KT/HAK/KUP transporters. In this study, we identified 16 putative K+-uptake transporter genes in peach (Prunus persica). To investigate the role of PpeKUP in maintaing K+ uptake, transport, and homeostasis, we applied abiotic stresses to peach seedlings and analysed physiological reactions and transcriptional responses of PpeKUP genes. The peach seedlings were sensitive to polyethylene glycol (PEG), Pb, and Cd, as evidenced by impaired growth, K+ nutrition, and photosynthetic performance. However, the peach seedlings were tolerant to aluminum. K+ deficiency mainly increased, whereas K+ excess reduced the PpeKUP gene expression in roots. The Al treatments enhanced the PpeKUP transcription in shoots, whereas PEG, Pd, and Cd enhanced the PpeKUP transcription in all tissues. Our findings provided molecular basis for K+ uptake, transport, and homeostasis in the peach seedlings, and revealed potential candidate genes for further functional determination or breeding of peaches.