Aims: KUP/HAK/KT transporters mainly play a role of K uptake in plants. PaHAK1 was a previously isolated KUP/HAK/KT transporter gene from a high K plant Phytolacca acinosa Roxb. In this study, we want to identify the function of PaHAK1. Methods: PaHAK1 was overexpressed in eukaryotes including Arabidopsis, rice, and yeast. The growth and K uptake of transgenic lines in media of low K concentration were investigated. Results: We found that PaHAK1 rescued the growth phenotype of athak5 seedlings which was hard to grow in the media of 10 μM K. Faster depletion from diluted K solutions was detected for transgenic than for WT plants. Moreover, PaHAK1 confers the growth of K uptake deletion yeast mutant on AP media containing 50 μM of K. Conclusions: Taken together, these results suggest an important role for PaHAK1 transporter on K uptake. [ABSTRACT FROM AUTHOR]