Abstract
Potassium is an essential element for plant, and high-affinity K+ uptake system plays a crucial role in potassium absorption and transportation. Here we report the isolation and characterization of a HKT1 homolog from C3 halophyte Suaeda salsa (L.) (SsHKT1), particularly under low K+ treatment. The SsHKT1 cDNA was 2033 nucleotides long including 1650 bp ORF for a 550 amino acids peptide and a predicted molecular mass of 63.0 kDa. The deduced amino acid sequence of SsHKT1 was 39–64% identical to other plant HKT-like sequences. A SsHKT1-specific antibody was prepared and reacted with a 63.0 kDa protein from S. salsa plasma membrane. Reverse transcriptase-PCR analysis showed that SsHKT1 was mainly expressed in leaf tissues and to a lesser extent, in root tissues. Amounts of SsHKT1 transcript were developmentally controlled and significantly up-regulated by K+ deprivation and NaCl treatment. The results suggested that SsHKT1 might play an important role in ion homeostasis and salt tolerance of S. salsa.
Acknowledgements
We are grateful for financial support by the NSFC (National Natural Science Research Foundation of China, project No: 30670177), Natural Science Research Foundation of Shandong Province (Z2004D03).