PutHKT2

Gene Details:

A high-affinity K+transporter PutHKT2|1|PutHKT2|1 cDNA was isolated from the salt-tolerant plant Puccinellia tenuiflora. Expression of PutHKT2|1|PutHKT2|1 was induced by both 300 mM NaCl and K+-starvation stress in roots, but only slightly regulated by those stresses in shoots.
PutHKT2|1|PutHKT2|1 transcript levels in 300 mM NaCl were doubled by the depletion of potassium. Yeast transformed with PutHKT2|1|PutHKT2|1, like those transformed with PhaHKT2|PutHKT2|1 from salt-tolerant reed plants (Phragmites australis), (i) were able to take up K+ in low K+ concentration medium or in the presence of NaCl, and (ii) were permeable to Na+.
This suggests that PutHKT2|1|PutHKT2|1 has a high affinity K+-Na+ symport function in yeast. Arabidopsis over-expressing PutHKT2|1|PutHKT2|1 showed increased sensitivities to Na+, K+, and Li+, while Arabidopsis over-expressing OsHKT2|PutHKT2|1 from rice (Oryza sativa) showed increased sensitivity only to Na+.
These findings demonstrate that the functional activity of PutHKTPutHKT2|1|5 and PutSOSPutHKT2|1 in P. tenuiflora roots is fine-tuned under saline conditions as well as by operation of other ion transporters/channel (PutHKTPutHKT2|1|4, PutHKT2|1|PutHKT2|1, and PutAKTPutHKT2|1).
These results show that the modes of action of PutHKT2|1|PutHKT2|1 in transgenic yeast and Arabidopsis differ from the mode of action of the closely related OsHKT2|PutHKT2|1 transporter.