Modulation of K+ translocation by AKT1 and AtHAK5 in Arabidopsis plants.
Plant Cell Environ
; 42(8): 2357-2371, 2019 08.
Article
em En
| MEDLINE
| ID: mdl-31046137
ABSTRACT
Root cells take up K+ from the soil solution, and a fraction of the absorbed K+ is translocated to the shoot after being loaded into xylem vessels. K+ uptake and translocation are spatially separated processes. K+ uptake occurs in the cortex and epidermis whereas K+ translocation starts at the stele. Both uptake and translocation processes are expected to be linked, but the connection between them is not well characterized. Here, we studied K+ uptake and translocation using Rb+ as a tracer in wild-type Arabidopsis thaliana and in T-DNA insertion mutants in the K+ uptake or translocation systems. The relative amount of translocated Rb+ to the shoot was positively correlated with net Rb+ uptake rates, and the akt1 athak5 T-DNA mutant plants were more efficient in their allocation of Rb+ to shoots. Moreover, a mutation of SKOR and a reduced plant transpiration prevented the full upregulation of AtHAK5 gene expression and Rb+ uptake in K+ -starved plants. Lastly, Rb+ was found to be retrieved from root xylem vessels, with AKT1 playing a significant role in K+ -sufficient plants. Overall, our results suggest that K+ uptake and translocation are tightly coordinated via signals that regulate the expression of K+ transport systems.
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MEDLINE
Assunto principal:
Potássio
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Canais de Potássio
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Arabidopsis
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Antiportadores de Potássio-Hidrogênio
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Proteínas de Arabidopsis
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article