SbHKT1;4, a member of the high-affinity potassium transporter gene family from Sorghum bicolor, functions to maintain optimal Na⺠/K⺠balance under Na⺠stress.
J Integr Plant Biol
; 56(3): 315-32, 2014 Mar.
Article
em En
| MEDLINE
| ID: mdl-24325391
ABSTRACT
In halophytic plants, the high-affinity potassium transporter HKT gene family can selectively uptake K⺠in the presence of toxic concentrations of Naâº. 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⺠stress, SbHKT1;4 expression was more strongly upregulated in salt-tolerant sorghum accession, correlating with a better balanced Na⺠/K⺠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⺠stress, and such hypersensitivity could be alleviated with the supply of elevated levels of Kâº, implicating that SbHKT1;4 may mediate K⺠uptake in the presence of excessive Naâº. Further electrophysiological evidence demonstrated that SbHKT1;4 could transport Na⺠and K⺠when expressed in Xenopus laevis oocytes. The relevance of the finding that SbHKT1;4 functions to maintain optimal Na⺠/K⺠balance under Na⺠stress to the breeding of salt-tolerant glycophytic crops is discussed.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Plantas
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Potássio
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Sódio
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Estresse Fisiológico
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Família Multigênica
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Proteínas de Transporte de Cátions
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Simportadores
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Sorghum
Idioma:
En
Revista:
J Integr Plant Biol
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
China