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Abstract: The purpose of this study is to investigate the function of a novel potassium transporter gene (NrHAK1) isolated from Nicotiana rustica roots using yeast complement and real-time PCR technique. The complementary DNA (cDNA) of NrHAK1, 2 488 bp long, contains an open reading frame (ORF) of 2 334 bp encoding a protein of 777 amino acids (87.6 kDa) with 12 predicted transmembrane domains. The NrHAK1 protein shows a high sequence similarity to those of high-affinity potassium transporters in Mesembryanthemum, Phytolacca acinosa, Arabidopsis thaliana, and so on. We found that the NrHAK1 gene could complement the yeast-mutant defect in K⁺ uptake. Among several tissues surveyed, the expression level of NrHAK1 was most abundant in the root tip and was up-regulated when exposed to potassium starvation. Moreover, the transcript accumulation was significantly reduced by adding 5 mmol/L NH₄⁺ to the solution. These results suggest that NrHAK1 plays an important role in potassium absorption in N. rustica.

[1] Ahn, S.J., Shin, R., Schachtman, D., 2004. Expression of KT/KUP genes in Arabidopsis and the role of root hairs in K⁺ uptake. Plant Physiol., 134(3):1135-1145.

[2] Banuelos, M.A., Garciadeblas, B., Cubero, B., Rodriguez-Navarro, A., 2002. Inventory and functional characterization of the HAK potassium transporters of rice. Plant Physiol., 130(2):784-795.

[3] Epstein, E., Rains, D.W., Elzam, O.E., 1963. Resolution of dual mechanisms of potassium absorption by barley roots. Proc. Natl. Acad. Sci., 49(5):684-692.

[4] Fernando, M., Kulpa, J., Siddiqi, Y.M., Glass, A.D.M., 1990. Potassium-dependent changes in the expression of membrane-associated proteins in barley roots. Plant Physiol., 92(4):1128-1132.

[5] Fu, H.H., Luan, S., 1998. AtKUP1: a dual-affinity K⁺ transporter from Arabidopsis. The Plant Cell, 10(1):63-73.

[6] Fulgenzi, F.R., Peralta, M.L., Mangano, S., Danna,C.H., Vallejo, A.J., Puigdomenech, P., Santa-María, G.E., 2008. The ionic environment controls the contribution of the barley HvHAK1 transporter to potassium acquisition. Plant Physiol., 147(1):252-262.

[7] Gierth, M., Maser, P., Schroeder, J.I., 2005. The potassium transporter AtHAK5 functions in K⁺ deprivation-induced high-affinity K⁺ uptake and AKT1 K⁺ channel contribution to K⁺ uptake kinetics in Arabidopsis roots. Plant Physiol., 137(3):1105-1114.

[8] Gietz, D.R., Schiestl, R.H., Willems, A.R., Woods, R.A., 1995. Studies on the transformation of intact yeast cells by the LiAc/SS-DNA/PEG procedure. Yeast, 11(4):355-360.

[9] Glass, A.D.M., Dunlop, J., 1978. The influence of potassium content on the kinetics of potassium influx into excised ryegrass and barley roots. Planta, 141(1):117-119.

[10] Hirsch, R.E., Lewis, B.D., Spalding, E.P., Sussman, M.R., 1998. A role for the AKT1 potassium channel in plant nutrition. Science, 280(5365):918-921.

[11] Kim, E.J., Kwak, J.M., Uozumi, N., Schroeder, J.I., 1998. AtKUP1: an Arabidopsis gene encoding high affinity potassium transport activity. The Plant Cell, 10(1):51-62.

[12] Langer, K., Ache, P., Geiger, D., 2002. Poplar potassium transporters capable of controlling K⁺ homeostasis and K⁺-dependent xylogenesis. The Plant Journal, 32(6):997-1009.

[13] Maathuis, F.J., Filatov, V., Herzyk, P., Krijger, G., Axelsen, K.B., Chen, S., Green, B.J., Yi, L., Madagan, K.L., Sanchez-Fernandez, R., et al., 2003. Transcriptome analysis of root transporters reveals participation of multiple gene families in the response to cation stress. The Plant Journal, 35(6):675-692.

[14] Martínez-Cordero, M.A., Martínez, V., Rubio, F., 2004. Cloning and functional characterization of the high-affinity K⁺ transporter HAK1 of pepper. Plant Molecular Biology, 56(3):413-421.

[15] Martínez-Cordero, M.A., Martinez, V., Rubio, F., 2005. High-affinity K⁺ uptake in pepper plants. Journal of Experimental Botany, 56(416):1553-1562.

[16] Nieves-Cordones, M., Martínez-Cordero, A.M., Martínez, V., Rubio, F., 2007. An NH₄⁺-sensitive component dominates high-affinity K⁺ uptake in tomato plants. Plant Science, 172(2):273-280.

[17] Pilot, G., Gaymard, F., Mouline, K., 2003. Regulated expression of Arabidopsis shaker K⁺ channel genes involved in K⁺ uptake and distribution in the plant. Plant Molecular Biology, 51(5):773-787.

[18] Qi, Z., Hampton, C.R., Shin, R., Barkla, B.J., White, P.J., Schachtman, D.P., 2008. The high affinity K⁺ transporter AtHAK5 plays a physiological role in planta at very low K⁺ concentrations and provides a caesium uptake pathway in Arabidopsis. Journal of Experimental Botany, 59(3):595-607.

[19] Quintero, F.J., Blatt, M.R., 1997. A new family of K⁺ transporters from Arabidopsis that are conserved across phyla. FEBS Letters, 415(2):206-211.

[20] Rigas, S., Debrosses, G., Haralampidis, K., Vicente-Agullo, F., Feldmann, K.A., Grabov, A., Dolan, L., Hatzopoulos, P., 2001. TRH1 encodes a potassium transporter required for tip growth in Arabidopsis root hairs. The Plant Cell, 13(1):139-151.

[21] Rodríguez-Navarro, A., 2000. Potassium transport in fungi and plants. Biochim Biophys Acta, 1469(1):1-30.

[22] Rodríuez-Navarro, A., Rubio, F., 2006. High-affinity potassium and sodium transport systems in plants. Journal of Experimental Botany, 57(5):1149-1160.

[23] Rubio, F., Santa-María, G.E., Rodriguez-Navarro, A., 2000. Cloning of Arabidopsis and barley cDNAs encoding HAK potassium transporters in root and shoot cells. Physiologia Plantarum, 109(1):34-43.

[24] Rufty, T.W., Jackson, W.A., Raper, D.C., 1982. Inhibition of nitrate assimilation in roots in the presence of ammonium: the moderating influence of potassium. Journal of Experimental Botany, 33(6):1122-1137.

[25] Santa-María, G.E., Rubio, F., Dubcovsky, J., Rodríguez-Navarro, A., 1997. The HAK1 gene of barley belongs to a large gene family and encodes a high-affinity potassium transporter. The Plant Cell, 9(12):2281-2289.

[26] Santa-María, G.E., Danna, C.H., Czibener, C., 2000. High-affinity potassium transport in barley roots: ammonium-sensitive and -insensitive pathways. Plant Physiol., 123(1):297-306.

[27] Schleyer, M., Bakker, E.P., 1993. Nucleotide sequence and 3′-end deletion studies indicate that the K⁺-uptake protein kup from Escherichia coli is composed of a hydrophobic core linked to a large and partially essential hydrophilic C terminus. J. Bacteriol., 175(21):6925-6931.

[28] Senn, M.E., Rubio, F., Banuelos, M.A., Rodriguez-Navarro, A., 2001. Comparative functional features of plant potassium HvHAK1 and HvHAK2 transporters. Journal of Biological Chemistry, 276(48):44563-44569.

[29] Su, H., Golldack, D., Zhao, C., Bohnert, H.J., 2002. The expression of HAK-type K⁺ transporters is regulated in response to salinity stress in common ice plant. Plant Physiol., 129(4):1482-1493.

[30] Wang, Y.H., Garvin, D.F., Kochian, L.V., 2002. Rapid induction of regulatory and transporter genes in response to phosphorus, potassium, and iron deficiencies in tomato roots. Evidence for cross talk and root/rhizosphere-mediated signals. Plant Physiol., 130(3):1361-1370.

[31] Wang, Z., Zhang, X., Fedida, D., 2000. Regulation of transient Na⁺ conductance by intra- and extracellular K⁺ in the human delayed rectifier K⁺ channel Kv1.5. The Journal of Physiology, 523(3):575-591.