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SbHKT1;4 , a member of the high‐affinity potassium transporter gene family from Sorghum bicolor , functions to maintain optimal Na + /K + balance under Na + stress
Author(s) -
Wang TianTian,
Ren ZhiJie,
Liu ZhiQuan,
Feng Xue,
Guo RuiQi,
Li BaoGuo,
Li LeGong,
Jing HaiChun
Publication year - 2014
Publication title -
journal of integrative plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.734
H-Index - 83
eISSN - 1744-7909
pISSN - 1672-9072
DOI - 10.1111/jipb.12144
Subject(s) - xenopus , gene family , transporter , potassium , arabidopsis thaliana , arabidopsis , mutant , gene , chemistry , gene expression , biology , biochemistry , microbiology and biotechnology , organic chemistry
In halophytic plants, the high‐affinity potassium transporter HKT gene family can selectively uptake K + in the presence of toxic concentrations of Na + . This has so far not been well examined in glycophytic crops. Here, we report the characterization of SbHKT1;4 , a member of the HKT gene family from Sorghum bicolor . Upon Na + stress, SbHKT1;4 expression was more strongly upregulated in salt‐tolerant sorghum accession, correlating with a better balanced Na + /K + ratio and enhanced plant growth. Heterogeneous expression analyses in mutants of Saccharomyces cerevisiae and Arabidopsis thaliana indicated that overexpressing SbHKT1;4 resulted in hypersensitivity to Na + stress, and such hypersensitivity could be alleviated with the supply of elevated levels of K + , implicating that SbHKT1;4 may mediate K + uptake in the presence of excessive Na + . Further electrophysiological evidence demonstrated that SbHKT1;4 could transport Na + and K + when expressed in Xenopus laevis oocytes. The relevance of the finding that SbHKT1;4 functions to maintain optimal Na + /K + balance under Na + stress to the breeding of salt‐tolerant glycophytic crops is discussed.