Cesium Inhibits Plant Growth Primarily Through Reduction of Potassium Influx and Accumulation in Arabidopsis.
Plant Cell Physiol
; 60(1): 63-76, 2019 Jan 01.
Article
em En
| MEDLINE
| ID: mdl-30219884
ABSTRACT
Cesium (Cs+) is known to compete with the macronutrient potassium (K+) inside and outside of plants and to inhibit plant growth at high concentrations. However, the detailed molecular mechanisms of how Cs+ exerts its deleterious effects on K+ accumulation in plants are not fully elucidated. Here, we show that mutation in a member of the major K+ channel AKT1-KC1 complex renders Arabidopsis thaliana hypersensitive to Cs+. Higher severity of the phenotype and K+ loss were observed for these mutants in response to Cs+ than to K+ deficiency. Electrophysiological analysis demonstrated that Cs+, but not sodium, rubidium or ammonium, specifically inhibited K+ influx through the AKT1-KC1 complex. In contrast, Cs+ did not inhibit K+ efflux through the homomeric AKT1 channel that occurs in the absence of KC1, leading to a vast loss of K+. Our observation suggests that reduced K+ accumulation due to blockage/competition in AKT1 and other K+ transporters/channels by Cs+ plays a major role in plant growth retardation. This report describes the mechanical role of Cs+ in K+ accumulation, and in turn in plant performance, providing actual evidence at the plant level for what has long been believed, i.e. K+ channels are, therefore AKT1 is, 'blocked' by Cs+.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Potássio
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Césio
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Arabidopsis
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Desenvolvimento Vegetal
Limite:
Animals
Idioma:
En
Revista:
Plant Cell Physiol
Ano de publicação:
2019
Tipo de documento:
Article